4.0 TFSI Misfires - VCDS logs, analysis, diagnostics and (hopefully) resolution

[///M Traitor]

This got started in another thread, but a few members including myself felt it was time to start a new thread regarding this topic of misfires, and hopefully introduce some sound scientific method to identifying and diagnosing this multi-cylinder misfire issue.

My car is a 2013 S6, bone stock, never tuned or modified other than AWE exhaust, I bought it new.

At the 20k mile mark, I started to notice occasional shudders and unsmooth acceleration with my car. It can be best described as that the car feels like it's having trouble building boost and like it's bogged down - feels weak, not like the torque monster I originally purchased. The power is not smooth during the misfire events (obviously) and this is felt as shudders through the chassis and the different torque levels can be felt as the car pulls. This typically happens at low/mid RPM and high load while sweeping up the rev range from low RPMs. So for example, accelerating while in a high gear and low RPM. It often happens when merging onto a highway, or accelerating when traffic clears. Seems to happen worse when the car was cruising for a while, and then I call for power with a roll on the accelerator. I can reproduce the problem in the 2k~4k RPM range, and maybe 1/2 to 3/4 throttle in D mode. I have felt misfires at higher RPMs, but generally speaking full throttle feels strong and smooth.

It should be noted, my car never threw a CEL or a diagnostic code for misfires.

As the shudders happened more and more, I started to realize these felt like misfires and started to look into the VCDS misfire logs and found a frightening amount of misfires lurking there. I changed my spark plugs around the 28k mark thinking this might be the issue, but it made no difference. The dealer turned me away saying that my extended warranty does not cover diagnostics, and that the 2.0Ts have way more misfires so it's not a problem.

I then started logging my misfires with the VCDS and saving the logs at different mileage intervals. At the time I started this logging, there was no chatter on the forums about misfires for untuned cars. I was alone in my quest. I tried fuel additives, switched fuels, and continued to collect the logs. Just recently I decided to consolidate the data into a graph, and low and behold it seems to tell a story. I plan to continue to collect data and add to this graph regularly.

https://farm5.staticflickr.com/4610/28138065169_b803dce23c_c.jpg

Cylinder #2 and #5 on my car are the ones with the most misfires. All of the lines on the graph appear to cross the 0 misfire point at 28k miles. This is around the time my ECU was flashed by the dealer and most likely the misfire logs were reset. If I had the earlier data, I wonder if it would have shown a nice curve suggesting a progressive problem? Starting with misfires at day 1 and getting more and more misfires per mile as the car aged? Or was there a point where the car started missing due to a broken part or malfunction or software error...

So the questions are: What is this problem caused by? Is it the dreaded carbon fouling on the valves ever increasing? Is it carbon inside of the combustion chamber? There are suggestions of oil-scrapers not working because of carbon interfering with their function. Is it a part that stops working properly but does not throw a code? Air tumblers in the intakes? Sensors going bad? Variable cam timing problems?

A fellow forum member resolved a CYL 3 hard miss by utilizing BG products additives. The thread is here (http://www.audizine.com/forum/showthread.php/791415-Cyl-3-misfire-again). His situation suggests carbon fouling of the oil scrapers was resolved by these additives.

I hope we can pull together as a community and see how widespread these misfires really are for cars that are NOT even throwing a code. If you have a VCDS, you can find the misfire tables by selecting Engine - > Advanced Meas. Values -> then select "Numb.of misfir" for each cylinder to see the recorded value. Please post your mileage, modifications, and misfire counts so perhaps we can make sense of this data and find a cause and maybe a solution.

[ryanlada]

Are you running the latest ECU revision?(I'm not sure how you tell) My 2016 was on revision 001 and it ran similar to your description. I had it in for a CEL related to the fuel sender and they updated it to revision 002. Engine performance was night and day different.

[ehofmann]

I was just reading this:

http://www.audizine.com/forum/showthread.php/336352-Audi-FSI-Engine-Carbon-Build-up-Megathread

Has some good info. I'm going to have my mechanic check out the intake valves when doing upgrades soon.


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[OlyS6]

This is just one point in time, but I plan on measuring this more frequently:

http://www.audizine.com/gallery/data/500/misfires.jpg

I have 18,000 miles on the car, and flashed to Stage 3 in early December of 2017. I have no idea if the flash reset the counters, but I suspect it may have. These misfires seem fairly evenly distributed so far, and they have not registered any CELs or thrown any codes to this point.

Thank you for starting this thread. I know several other folks are registering a fair number of misfires as well.

[MadAboutCars]

My misfire count for a MY16 S6 Unitronic Stage 1, done about 9000 kilometers since last flash. It's done 34k kilometers in total.

https://vdsjnq.dm2301.livefilestore.com/y4m1Y6wzAjAIlAYhARai2K4COYOrr7_KmTccOUhxPz0rV3c3li LrvNlRQe3ADVEYy8xD_STLcoyhjMyzmzOaLaDlvBqXsOJudmnw CvA7PfBXgwM5oJ-pnHteVHXNZX0NFZQf3du3pedeSkC6LzsWPcGr0ZnaYrxsDv34v jSIgjWdeBtTFTkJsNWcB9Ldq-rs_oyf9AfNgf9ecckiAFjhLej4Q?width=4032&height=2268&cropmode=none

[pez81]

Could it be carbon build up?

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[lapsandwich]

This got started in another thread, but a few members including myself felt it was time to start a new thread regarding this topic of misfires, and hopefully introduce some sound scientific method to identifying and diagnosing this multi-cylinder misfire issue.

My car is a 2013 S6, bone stock, never tuned or modified other than AWE exhaust, I bought it new.





At the 20k mile mark, I started to notice occasional shudders and unsmooth acceleration with my car. It can be best described as that the car feels like it's having trouble building boost and like it's bogged down - feels weak, not like the torque monster I originally purchased. The power is not smooth during the misfire events (obviously) and this is felt as shudders through the chassis and the different torque levels can be felt as the car pulls. This typically happens at low/mid RPM and high load while sweeping up the rev range from low RPMs. So for example, accelerating while in a high gear and low RPM. It often happens when merging onto a highway, or accelerating when traffic clears. Seems to happen worse when the car was cruising for a while, and then I call for power with a roll on the accelerator. I can reproduce the problem in the 2k~4k RPM range, and maybe 1/2 to 3/4 throttle in D mode. I have felt misfires at higher RPMs, but generally speaking full throttle feels strong and smooth.

It should be noted, my car never threw a CEL or a diagnostic code for misfires.

As the shudders happened more and more, I started to realize these felt like misfires and started to look into the VCDS misfire logs and found a frightening amount of misfires lurking there. I changed my spark plugs around the 28k mark thinking this might be the issue, but it made no difference. The dealer turned me away saying that my extended warranty does not cover diagnostics, and that the 2.0Ts have way more misfires so it's not a problem.

I then started logging my misfires with the VCDS and saving the logs at different mileage intervals. At the time I started this logging, there was no chatter on the forums about misfires for untuned cars. I was alone in my quest. I tried fuel additives, switched fuels, and continued to collect the logs. Just recently I decided to consolidate the data into a graph, and low and behold it seems to tell a story. I plan to continue to collect data and add to this graph regularly.

https://farm5.staticflickr.com/4610/28138065169_b803dce23c_c.jpg

Cylinder #2 and #5 on my car are the ones with the most misfires. All of the lines on the graph appear to cross the 0 misfire point at 28k miles. This is around the time my ECU was flashed by the dealer and most likely the misfire logs were reset. If I had the earlier data, I wonder if it would have shown a nice curve suggesting a progressive problem? Starting with misfires at day 1 and getting more and more misfires per mile as the car aged? Or was there a point where the car started missing due to a broken part or malfunction or software error...

So the questions are: What is this problem caused by? Is it the dreaded carbon fouling on the valves ever increasing? Is it carbon inside of the combustion chamber? There are suggestions of oil-scrapers not working because of carbon interfering with their function. Is it a part that stops working properly but does not throw a code? Air tumblers in the intakes? Sensors going bad? Variable cam timing problems?

A fellow forum member resolved a CYL 3 hard miss by utilizing BG products additives. The thread is here (http://www.audizine.com/forum/showthread.php/791415-Cyl-3-misfire-again). His situation suggests carbon fouling of the oil scrapers was resolved by these additives.

I hope we can pull together as a community and see how widespread these misfires really are for cars that are NOT even throwing a code. If you have a VCDS, you can find the misfire tables by selecting Engine - > Advanced Meas. Values -> then select "Numb.of misfir" for each cylinder to see the recorded value. Please post your mileage, modifications, and misfire counts so perhaps we can make sense of this data and find a cause and maybe a solution.

Check your turbos.
Not even kidding, I have low kms and my car was at the dealership for a unrelated problem that the car was in for. They told me the compressor wheels contacted the compressor housing. Tsb on the 4.0t engines for the turbos failing. Totally unexpected, but I’ve read it’s becoming more common on these cars.

[Dasquade]

Check your turbos.
Not even kidding, I have low kms and my car was at the dealership for a unrelated problem that the car was in for. They told me the compressor wheels contacted the compressor housing. Tsb on the 4.0t engines for the turbos failing. Totally unexpected, but I’ve read it’s becoming more common on these cars.
You have more info on this? Especially what side are we talking about....cold side or the hot side?
I wanted to keep this topic bit offtopic free etc, but i have very simular issues like OP and for my the shudder/powerlack is only present when i have turbo boost building up (+70%). Without turbo boost (the laptimer indicator), no issues. I had checked the hot side of my turbines when i swapped downpipes (around 5k km ago and no play on the shafts, but didn't looked at the other side). But very curious as in a way it feels turbo related...

[brian_216]

You have more info on this? Especially what side are we talking about....cold side or the hot side?
I wanted to keep this topic bit offtopic free etc, but i have very simular issues like OP and for my the shudder/powerlack is only present when i have turbo boost building up (+70%). Without turbo boost (the laptimer indicator), no issues. I had checked the hot side of my turbines when i swapped downpipes (around 5k km ago and no play on the shafts, but didn't looked at the other side). But very curious as in a way it feels turbo related...Compressor housing = cold side
Turbine housing = exhaust (hot) side

At least that is what I have always heard them referred to.

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[brian_216]

I was just reading this:

http://www.audizine.com/forum/showthread.php/336352-Audi-FSI-Engine-Carbon-Build-up-Megathread

Has some good info. I'm going to have my mechanic check out the intake valves when doing upgrades soon.


Sent from my iPhone using TapatalkWhat kind of upgrades? You need to pull the engine to see the intake valves. (At least to do anything to them like a cleaning) you may be able to see them with a scope, but this would require the intercooler housing to be removed.

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[Frenetic]

Interesting chart to look at.

Anyone know the cylinder number per bank?

Does it go 1-4 on one side from front to back and 5-8 the other side front to bank? Anyone have a diagram or schematic of the cylinder numbers and position in the engine?

Just trying to visualize where cylinders 2 and 5 are.

[brian_216]

Interesting chart to look at.

Anyone know the cylinder number per bank?

Does it go 1-4 on one side from front to back and 5-8 the other side front to bank? Anyone have a diagram or schematic of the cylinder numbers and position in the engine?

Just trying to visualize where cylinders 2 and 5 are.1 to 4 passenger side front being 1, rear is 4.
5 to 8 driver side, front being 5 rear is 8.

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[Turbo-Dad]

Here is the way the cylinders are numbered:

https://uploads.tapatalk-cdn.com/20180128/cf773621b5aa8c449a9e29d0fa34ccec.jpg

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[Kczach]

It would be interesting to see if the misfires decreased if the cylinder on demand feature was deactivated.

[///M Traitor]

Check your turbos.
Not even kidding, I have low kms and my car was at the dealership for a unrelated problem that the car was in for. They told me the compressor wheels contacted the compressor housing. Tsb on the 4.0t engines for the turbos failing. Totally unexpected, but I’ve read it’s becoming more common on these cars.

I will check the compressor wheels. Will it be obvious if they have made contact with the housing? Am I looking for shrapnel, or just some signs of scuffing?

I have logged requested boost vs actual, and the charts are highly correlated so I ruled out the turbos, but perhaps prematurely...

[brian_216]

It would be interesting to see if the misfires decreased if the cylinder on demand feature was deactivated.I agree. I think when the cylinder on demand kicks in that there would have to be a misfire or 2 happening. It cant possibly be that seamless. But when my car goes in to 4 cyl mode I cant feel it at all. No signs of it happening other than the mpg bar going green.



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[///M Traitor]

It would be interesting to see if the misfires decreased if the cylinder on demand feature was deactivated.

It would be interesting.. I’d bet with 4-cyl mode disabled, the misfires would decrease in the active cylinders as 4-cyl mode operates the active cylinders at higher loads compared to 8-cyl mode at the same torque request. High torque at low rpms is when ignition related misfires are more likely to happen (if I understand correctly). But I don’t think this means 4-cyl mode is the problem. It means that the problem is effecting 4-cyl mode as well, and moreso those cylinders because they are never inactive.

[Hofahome]

What kind of upgrades? You need to pull the engine to see the intake valves. (At least to do anything to them like a cleaning) you may be able to see them with a scope, but this would require the intercooler housing to be removed.

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Regarding the upgrades, can't say much more other than it is the turbos (and downpipes) and you may be a good candidate. I get the turbos this week. They are not rs turbos btw.
Since they are going to have access to the charge cooler, I'll probably pay them a little more to pull the intercooler and throw a scope down to check out the intake valves. Same thing with changing out the plugs and checking out the cylinders.

[Dasquade]

It would be interesting.. I’d bet with 4-cyl mode disabled, the misfires would decrease in the active cylinders as 4-cyl mode operates the active cylinders at higher loads compared to 8-cyl mode at the same torque request. High torque at low rpms is when ignition related misfires are more likely to happen (if I understand correctly). But I don’t think this means 4-cyl mode is the problem. It means that the problem is effecting 4-cyl mode as well, and moreso those cylinders because they are never inactive.
Like i posted in other topic, in my case the shudder didn't dissapeared after i got my COD completly disabled by my tuner, so at least that rules out the causer in my case. Again, every car is different, tune, wear etc...but sounds we have very simular issue (compaited to Brian's issue he fixed). Misfire count has been reduced for my car since i started using the 1/10 mixture bio ethanol, but overall it isn't a fixer as i still have the shudder and misfires, especially when i recreate the high loud/high gear/mid rpms/70% boost. I know i should stop investigating it myself and simply bring it to my tuner, detune, factory upgrade and retune based on those upgrades (it is one of the solutions for some, wanted or unwanted effect). Currently still waiting it out and replacing coils (RS coils on the way) and meanwhile replace the "M" plugs with a recent brandnew/secondhand NGK race plugs. One of these days the BG cure products should arrive and will do that part first aswell. Once that is done (most likely it won't change the shudder), i'll be heading to my tuner (so at least i know it ain't coil/plug/oil related). While replacing the plugs i'll de a borescope look in the cylinders (should of done the first time).
@Brian: did you ever tested your old injector if it was cluttered/dirty/not fully injecting anymore?
@///M Traitor: you experience the shudder at full WOT (lower gear/full boost/+4.000rpms)? Did you manage to log timing adjustments when the car starts to shudder? Sadely i haven't logged that part yet (for the moment i try not to trigger it too much).

For what it is worth, put my borescope in the intake pipes and looked around the turbines. Sadely i couldn't see inside/between the fins and inspect the housing, but visually nothing looked bad. No signs of abnormal wear beside maybe 1 or 2 thinny cuts on the front of blades, but i suppose a visual inspection from inside the exit side (pipes going to throttle body) would be better but bit scared to take of the rubber tubes (taking them of might work but back on looks like a bitch).

For what it is worth, i got my most misfires on the different cylinder, 1 & 6 (the old non active cylinders, currently full V8 active).

[Hothead309]

Hey guys,
I need some help please.
My a6 c5 is giving this code 08010 along with some misfire,
Any one knows what is this code and how to possible fix the problem?
Thanks in advance for the help.

[brian_216]

Like i posted in other topic, in my case the shudder didn't dissapeared after i got my COD completly disabled by my tuner, so at least that rules out the causer in my case. Again, every car is different, tune, wear etc...but sounds we have very simular issue (compaited to Brian's issue he fixed). Misfire count has been reduced for my car since i started using the 1/10 mixture bio ethanol, but overall it isn't a fixer as i still have the shudder and misfires, especially when i recreate the high loud/high gear/mid rpms/70% boost. I know i should stop investigating it myself and simply bring it to my tuner, detune, factory upgrade and retune based on those upgrades (it is one of the solutions for some, wanted or unwanted effect). Currently still waiting it out and replacing coils (RS coils on the way) and meanwhile replace the "M" plugs with a recent brandnew/secondhand NGK race plugs. One of these days the BG cure products should arrive and will do that part first aswell. Once that is done (most likely it won't change the shudder), i'll be heading to my tuner (so at least i know it ain't coil/plug/oil related). While replacing the plugs i'll de a borescope look in the cylinders (should of done the first time).
@Brian: did you ever tested your old injector if it was cluttered/dirty/not fully injecting anymore?
@///M Traitor: you experience the shudder at full WOT (lower gear/full boost/+4.000rpms)? Did you manage to log timing adjustments when the car starts to shudder? Sadely i haven't logged that part yet (for the moment i try not to trigger it too much).

For what it is worth, put my borescope in the intake pipes and looked around the turbines. Sadely i couldn't see inside/between the fins and inspect the housing, but visually nothing looked bad. No signs of abnormal wear beside maybe 1 or 2 thinny cuts on the front of blades, but i suppose a visual inspection from inside the exit side (pipes going to throttle body) would be better but bit scared to take of the rubber tubes (taking them of might work but back on looks like a bitch).

For what it is worth, i got my most misfires on the different cylinder, 1 & 6 (the old non active cylinders, currently full V8 active).Yes, sent out for testing at an injector cleaning place that uses an ansu machine. Failed, not closing all the way. Dribble of fuel when in the closed position.

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[kpriv]

I think I win (lose?) the misfires relative to miles game. I'm at 17k miles; last flash was to stage 2 at ~9k miles. I have never had a flashing CEL or felt the engine "stumbling"

To the extent the issues can be caused/exacerbated by fuel issues, I can think of two leading causes for me:
1) I'm in los angeles, and I would venture a guess that we have some of the worst 91 octane around (pure speculation, but would not surprise me at all)
2) Last summer, I found 100 octane fuel at the pump at a nearby gas station. I was blending this with 91 octane to run the 93 octane file on my tune for ~4-6 weeks. Chris at EPL was kind enough to warn me off of that saying they've had some of their customers test and the 100 octane at a station is typically bad given how long it sits at the pump. No clue how many misfires I racked up during that period, but likely some.

I'm curious to know if reflashing your ECU causes the vcds count to reset (someone with an EPL tune could tell us pretty simply); if so I may find a time to re-flash and start clean. In any event, I'll start checking every 1k miles or so and update here.

https://i.imgur.com/47OZHjy.jpg

[///M Traitor]

@///M Traitor: you experience the shudder at full WOT (lower gear/full boost/+4.000rpms)? Did you manage to log timing adjustments when the car starts to shudder? Sadely i haven't logged that part yet (for the moment i try not to trigger it too much).

I have been able to replicate the misfires in manual mode with the pedal down as far as possible without depressing the kickdown switch. But I’m my case it’s intermittent so i assume it’s hard to log the ignition timing around events. They occur sporadically and rarely back to back. I have most success reproducing the misfires when the trans is in D for some reason.

I remember a few values in VCDS for cam timing. Which is the correct one to log?

[///M Traitor]

I think I win (lose?) the misfires relative to miles game. I'm at 17k miles;

https://i.imgur.com/47OZHjy.jpg

Holy schnikies, I think you did win so far 😅

[Dasquade]

I have been able to replicate the misfires in manual mode with the pedal down as far as possible without depressing the kickdown switch. But I’m my case it’s intermittent so i assume it’s hard to log the ignition timing around events. They occur sporadically and rarely back to back. I have most success reproducing the misfires when the trans is in D for some reason.

I remember a few values in VCDS for cam timing. Which is the correct one to log?
Same, not always happening so indeed bit hard to log. My tought is, especially in D it happens because it puts stress and you on the top of your torque peak, that while you driving in worst performance condition (grandma style/diesel driving instead of using the v8 higher revs).
As for the timing, if not mistaken you need to log:
*timing angle retardation (can be messured on all cylinders and ideally that should read 0°)
*ignition timing adjustment cylinder 1 (only 1 cylinder can be read and value there should run between 0 and max 30 afaik...negative and positive).
Ideally maybe logging with fuel rail pressure...
There is an camshaft timing test (2 tests) aswell, witch i passed without issues. More and more starting to think it is purely a tune issue :s.
Did your car has the latest ecu/tcu software updates?
Starting to see a pattern most 2013 models are effected...

[averagejoe26]

Having 41k on my 2013 s6, i only got misfires when i let my car sit for a few days, everytime being cylinder 3,5, and 7. I would drive it pretty hard for a hour or so and the misfires will not go away until i reset the computer. Being my first car with direct injection, i am by no means a expert on this matter.

[elp_jc]

I would drive it pretty hard for a hour or so and the misfires will not go away until i reset the computer.
May I ask how exactly do you do that? Many thanks.

[///M Traitor]

Did your car has the latest ecu/tcu software updates?
Starting to see a pattern most 2013 models are effected...

I believe at the 28k mark my dealer updated the ECU and TCU to the latest version. Is there a way to tell in the VCDS? I pondered the idea of an OEM tuning issue causing this, but then why wouldn’t the aftermarket tuners fix and boast about this? And tuned cars are suffering misfires as well, no?

[Dasquade]

I believe at the 28k mark my dealer updated the ECU and TCU to the latest version. Is there a way to tell in the VCDS? I pondered the idea of an OEM tuning issue causing this, but then why wouldn’t the aftermarket tuners fix and boast about this? And tuned cars are suffering misfires as well, no?
No sure how you do it with vcds (i got obd11) but normally when you go to your engine module and scan it, it should be give you software/firmware and hardware numbers. Will check out mine and same for transmittion but since it is tuned i might not able to see it (read something when tuned it shows X for the dealers).
Still waiting for my parts (coils/plugs/BG)...car holding strong with no issues (soft driving and flooring it, didn't played around it the 'shudder zone').

[averagejoe26]

May I ask how exactly do you do that? Many thanks.

I would just clear the cel and immediately after that my car will idle just fine and show no hesistation during low rpm pulls.

[SleekS7]

I'm curious to know if reflashing your ECU causes the vcds count to reset (someone with an EPL tune could tell us pretty simply); if so I may find a time to re-flash and start clean. In any event, I'll start checking every 1k miles or so and update here.



Yes, a reflash clears the misfire counts. I've done it several times and always reset to 0 for all cylinders.

[kpriv]

Yes, a reflash clears the misfire counts. I've done it several times and always reset to 0 for all cylinders.

Thanks! Maybe I'll do that in order to help myself out from an optics perspective [:D]

[Chris Morales]

It's either been either 7K or 17K miles since my last reflash (not sure if adding the 104 tune was a reflash). I have a misfire count of 2300+ on cyl 5 and 600+ on cyl 1. Counts in the other cylinders are much smaller. Cyl 8 only has around 80.

So for me, it's those two front cylinders that are the biggest problems. Seems like most everyone has an issue with cyl 5.

[P_G]

I gather having an APR tune installed will reset the counters, if so I've had a similar number of misfires on cylinders 1,2,5&8 at around the 200 mark but only double digits on the others and that would have been since November 25, 2017 which is 3-4k miles. Not bad but not brilliant however I would say that I suspect a lot of that was when the plugs weren't gapped properly and on old plugs. It used to happen a lot then but recently it's only been at low rpm and high load in high gear, 7&8. After 1800rpm in 8th the 'roughness' disappears.

Will keep logging on a weekly basis going forward and try the BG products at my next oil change in 4-5k miles time.

[ehofmann]

https://uploads.tapatalk-cdn.com/20180206/cbb1698db2ee5764b6ef1139f858e475.jpg

I forget when I flashed my car last. Good old cyl 5. No cel or codes though


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[ryanlada]

I believe at the 28k mark my dealer updated the ECU and TCU to the latest version. Is there a way to tell in the VCDS? I pondered the idea of an OEM tuning issue causing this, but then why wouldn’t the aftermarket tuners fix and boast about this? And tuned cars are suffering misfires as well, no?

I believe the tunes are based on a particular factory version as it's base. All I can say is my 2016 s6 ran poorly on the factory 001 version of the ecu software (surging, low on power odd acceleration). It felt slower than my stage 2 b8 still and with nothing to compare it to, I just assumed that the b8 stage 2 was just faster. It went in for a cel and as a part of the fix the dealer applied the latest ECU software version 002. After that the car picked up a ton of power, smoother, etc. If you're on a factory tune, I would recommend you see if there is an update they can apply. Drive it 200 miles or so after the flash to let it adapt and see how it goes (same as any flash, factory or aftermarket)

[brian_216]

I winhttps://uploads.tapatalk-cdn.com/20180206/53f9ccc957a99f4af92a029957df6f0f.jpg

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[Hofahome]

I winhttps://uploads.tapatalk-cdn.com/20180206/53f9ccc957a99f4af92a029957df6f0f.jpg

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what the eff man. Can you post up any more logs specific to cyl 3?

[brian_216]

what the eff man. Can you post up any more logs specific to cyl 3?Im limited with the snap on tool. No vcds at my fingertips right now

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[DGVR6]

What is the OE spark plug gap?

[Dasquade]

What is the OE spark plug gap?
My oem ngk "m" plugs came out the box gapped 0.6mm/0.024", same gap on my ngk 'race' plugs (unless gab tollerance is that small and it wasnt really measurable for me).

[DGVR6]

Anyone gapped at 0.026? If so, can you post up your misfire counts?

[brian_216]

Ok, so on Feb 5th before running my second round of BG I had this for my misfire count.

https://uploads.tapatalk-cdn.com/20180217/df9e2088be0118ee8ec6b5dae0088ec9.jpg

Today I pulled it again and it looks like I have less on cyl 4 since then compared to the other cylinders. https://uploads.tapatalk-cdn.com/20180217/9f34de4645454de379121d992ee0bf22.jpg

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[brian_216]

Can anyone tell me how to reset the misfire counter?https://uploads.tapatalk-cdn.com/20180219/45d002648163ad1f4726feb1be170197.jpg

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[Dasquade]

Can anyone tell me how to reset the misfire counter?https://uploads.tapatalk-cdn.com/20180219/45d002648163ad1f4726feb1be170197.jpg

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I think it can only be resetted by retuning, since you have EPL it might be a easy job (back to stock, back to tune).

[///M Traitor]

OK ladies and gents. I have made use of my time. I decided to give the mechanic-in-a-bottle solution a go, namely the BG products EPR, MOA and 44k. I decided to do it systematically as to see what product had the most effect in reducing the misfire counts (if any).

I started out with one can of 44k added to my fuel tank just before filling her up. I pulled the misfire logs immediately before refueling, so I'd have a hard data point to reference before treatment vs after treatment. When I was done driving on that tank of fuel, I pulled the logs to find that there was only a slight improvement in CYL 2. Interesting, but not remarkable. Maybe a clogged injector was contributing to misfires in that cylinder? It's obviously still misfiring though.

I then did the EPR treatment. Ran the car at operating temperature with TWO cans of EPR in the oil, 1200rpm for about 20 minutes. I should note I got a code for excessive fuel pressure bank 2 during this treatment (soft code, no CEL). Perhaps unrelated? The EPR stuff smells exactly like PVC cleaner to me. It seems to have some serious dissolving power based on the smell and the way the oil poured out like water when changing it. New oil filter, 8 quarts of Pennzoil Platinum Euro 5W-40, and one can of MOA. I then ran a full tank of fuel again (no additives) and pulled the logs tonight. My gut was telling me that the car felt slightly stronger and idled smoother, but the logs say HORSE CRAP! How frustrating. No apparent change whatsoever for the EPR and MOA treatment.

https://farm5.staticflickr.com/4621/39659500584_50e755ec6c_b.jpg

[brian_216]

There is no doubt in my mind the EPR cleans and removes a lot of junk from the engine. I think my positive experience is also related to changing out to a fresh spark plug on my problem cylinder the 2 times I ran the EPR.

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[///M Traitor]

Hi Brian, I’m glad your issue was addressed with the BG products. Mine unfortunately was not. Have you had a chance to pull you’re misfires with a scanner? I’m curious to see if your engine is experiencing the same as other S6s with excessive misfires (that do not trigger a CEL)

[brian_216]

This was today.https://uploads.tapatalk-cdn.com/20180220/702dabd5c6c0482ced0afef9617b872c.jpg

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[///M Traitor]

Dude, I’m retarded, I missed that just a few posts above me.. sorry!

That’s a heck of a lot of misfires. Do you have any other data points to see what the misfire rate is? (per mile, etc)

[kpriv]

///M — I’m glad you got this thread started. I have a 2016 and have never had a CEL. 17.6k miles on the clock. I checked about a month ago at 17k (7k since my last flash) and pasted an image of my misfire count above.

I just checked again today and I am averaging right around 50 misfires per 1,000 miles in the past month (other than cylinder 5 which is an egregious 200 per 1k), which is consistent with the trend for the 7k miles since my last flash.

I would love to figure out (1) the root cause of these, (2) if I have a major issue festering, and (3) what is a “normal/acceptable” level of misfires for these engines assuming no flashing CEL. Shot in the dark, but would love for Tony or someone from APR to chime in with their thoughts on the issue.


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[Frenetic]

Isn’t there some inherent misfire everytime it switches to four-cylinder mode?

I thought I read that in the self-study guide or somewhere, but the transition itself, at least the first on or off may have a misfire that is logged? I remember reading the computer will severely retard ignition upon 4 cylinder activation, which could cause a misfire. I’m just basing this on my foggy recollection and could be wrong.

Also, this might not explain other misfires due to carbon buildup.

[Dasquade]

Isn’t there some inherent misfire everytime it switches to four-cylinder mode?

I thought I read that in the self-study guide or somewhere, but the transition itself, at least the first on or off may have a misfire that is logged? I remember reading the computer will severely retard ignition upon 4 cylinder activation, which could cause a misfire. I’m just basing this on my foggy recollection and could be wrong.

Also, this might not explain other misfires due to carbon buildup.
That was my tought aswell and why i deactivated COD. My misfires didnt changed by that....but fact, my car still had the loose exhaust bolts.
Carring logging my car and misfires specificly now he is again powercut free!
In case, 81.000km car, imho the epr and/or new plugs/coil did make the car run smoother.
Imho it aint bad to do epr threadment once in a while...

For what i heard, the 4.0tt is indeed misfire happy, especially tuned. Both confirmed by my dealer and tuner itself. Still bit wondering if i should detune, upgrade stock ecu software and retune based on that upgrade as it kinda adresses the misfire issues (on the rs at least).

[Tuner1]

Hi guys im new here, sorry about my english...

I drive a Rs6 Performance year 2016 with catless downpipes, forge intercooler, complete 3" exhaust system, hfp from loba (over180bar) and i have also the misfires...
i changed already 3 times (in 20.000km) the plugs but always same problem with cylinder 5. At the moment i have the 001 software but next week i go to make the update to the 003... Audi say that the 003 is to solve the misfire problems.... we will see... if the 003 dont helps there exist a tpi for the s8plus and also for the rs6/7 Performance i let you know if the 003 works...

[mavpsire]

Figured I would add to this thread seeing that I am experiencing this as well. In the 3 months and 3000km/1875mi I've owned this car, I've had the flashing CEL and CEL ON twice now because of a Cyl 5 misfire.

Each time its been well below freezing and with oil temp hovering at -15C/5F, oil temp hovering around 90C/194F and full load / boost. I've been careful to only request full power after it thoroughly warming up.

Question: what is the difference between a logged misfire (in the count below) and a flashing cel / cel on ? Does the CEL simply indicate the misfire is occurring repeatedly at that particular time?

Questtion 2: In addition to the theory of perhaps COD activation causing these (not likely given I'm requesting 100% power), what about traction control?

http://binaverse.com/docs/rs7/misfires.png

[Dasquade]

Figured I would add to this thread seeing that I am experiencing this as well. In the 3 months and 3000km/1875mi I've owned this car, I've had the flashing CEL and CEL ON twice now because of a Cyl 5 misfire.

Each time its been well below freezing and with oil temp hovering at -15C/5F, oil temp hovering around 90C/194F and full load / boost. I've been careful to only request full power after it thoroughly warming up.

Question: what is the difference between a logged misfire (in the count below) and a flashing cel / cel on ? Does the CEL simply indicate the misfire is occurring repeatedly at that particular time?

Questtion 2: In addition to the theory of perhaps COD activation causing these (not likely given I'm requesting 100% power), what about traction control?

http://binaverse.com/docs/rs7/misfires.png
Bit noob here, but...
1. i think it is indeed a preset amount of misfires within a short time. If not mistaken tought audi raised the limit a bit for not throwing a cel or even limp mode that easly. But again, not sure....
2. It was never confirmed COD caused misfires, read it in the past aswell and one of the reasons i wanted it out (but also the soft powercuts and noise difference etc). Since i deactivated my misfires weren't reduced (but still had my exhaust leak i wasn't aware of untill few days ago). Even since i have found my exhaust leak and mostlikely messing my lambda values constantly, i'm still getting a soft amount of unfeelable misfires. My tuner mentioned the gear shifting itself could also contribute to misfires that are logged and i shouldn't worry too much (i suppose it is a 'fantasy' having a perfectly non misfiring engine?). But he also mentioned for a different reason i should reset me long term selflearning program because of the misleading info and lambda values in the past. Apperently it takes some time (up to 2 weeks or so to settle down).
Buttom line might be, take the misfire count with some sault and unless there are big differences or actual feelable misfires, you should worry.

In your case, i suppose it is the famous 'cylinder 5 - RS apr stage 2' issue and should hopefully adressed soon.

[mavpsire]

Bit noob here, but...
1. i think it is indeed a preset amount of misfires within a short time. If not mistaken tought audi raised the limit a bit for not throwing a cel or even limp mode that easly. But again, not sure....
2. It was never confirmed COD caused misfires, read it in the past aswell and one of the reasons i wanted it out (but also the soft powercuts and noise difference etc). Since i deactivated my misfires weren't reduced (but still had my exhaust leak i wasn't aware of untill few days ago). Even since i have found my exhaust leak and mostlikely messing my lambda values constantly, i'm still getting a soft amount of unfeelable misfires. My tuner mentioned the gear shifting itself could also contribute to misfires that are logged and i shouldn't worry too much (i suppose it is a 'fantasy' having a perfectly non misfiring engine?). But he also mentioned for a different reason i should reset me long term selflearning program because of the misleading info and lambda values in the past. Apperently it takes some time (up to 2 weeks or so to settle down).
Buttom line might be, take the misfire count with some sault and unless there are big differences or actual feelable misfires, you should worry.

In your case, i suppose it is the famous 'cylinder 5 - RS apr stage 2' issue and should hopefully adressed soon.

Very good points... I will keep that in mind as the car seems to drive just fine 99.9% of the time and is just a bit unnerving with the flashing CEL during full power on the odd occasion.

Just to confirm again though - the flashing CEL and CEL ON for the misfire is just an indication of the misfire occoring frequently enough within that given time frame and not indicative of anything else?

I am dropping by my tuner today to have them transfer ownership of the tune into my name and reflash the car and confirm its on the proper map just in case its on 91 and im pumping 94....

[Dasquade]

Very good points... I will keep that in mind as the car seems to drive just fine 99.9% of the time and is just a bit unnerving with the flashing CEL during full power on the odd occasion.

Just to confirm again though - the flashing CEL and CEL ON for the misfire is just an indication of the misfire occoring frequently enough within that given time frame and not indicative of anything else?

I am dropping by my tuner today to have them transfer ownership of the tune into my name and reflash the car and confirm its on the proper map just in case its on 91 and im pumping 94....
Afaik indeed about the CEL + the CEL will throw a stored error code where as 'random' misfires will never throw one (unless it can be defined).
*offtopic: still odd i was getting so much powercuts and at such specific condition, i still fail to see why i didn't get an P error (or any code identifing i had an exhaust leak). It only did once...

Anyway, while you at the tuner, you might want them to check what OEM software version the current tune is based on and make sure they install the latest apr tune (not familiar with apr and not sure if their latest tune includes the OEM misfiring software version).

[Sanjman]

Hey guys,
I need some help please.
My a6 c5 is giving this code 08010 along with some misfire,
Any one knows what is this code and how to possible fix the problem?
Thanks in advance for the help.
You're posting in the C7 subforum... you'll get better answers in the C5 S6 forums.

[brian_216]

I will be opening my wire harness from cyl 3 coil all the way back to the ECU. The erratic behavior of the rough idle and running on 7 out of 8 and then going away by a key cycle and a 10 or so min stop leads me to this conclusion. That and I have already addressed every other variable. I'm hoping to find cracked wire insulation like on the old 1.8t. That or a bad ground, dirty connection, anything at this point. I will report back. I attached images of what used to cause this problem on the old 1.8t cars. Hoping this is it this time. There is so much heat under the hood from the turbos, this makes sense.https://uploads.tapatalk-cdn.com/20180224/452834049c864f92590fc32ef0ec2518.jpghttps://uploads.tapatalk-cdn.com/20180224/57bb2961db2dadae70b1e1990d0de955.jpg

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[Cris_OO7]

I will be opening my wire harness from cyl 3 coil all the way back to the ECU. The erratic behavior of the rough idle and running on 7 out of 8 and then going away by a key cycle and a 10 or so min stop leads me to this conclusion. That and I have already addressed every other variable. I'm hoping to find cracked wire insulation like on the old 1.8t. That or a bad ground, dirty connection, anything at this point. I will report back. I attached images of what used to cause this problem on the old 1.8t cars. Hoping this is it this time. There is so much heat under the hood from the turbos, this makes sense.https://uploads.tapatalk-cdn.com/20180224/452834049c864f92590fc32ef0ec2518.jpghttps://uploads.tapatalk-cdn.com/20180224/57bb2961db2dadae70b1e1990d0de955.jpg

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Good Luck Brian hope u find something.


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[///M Traitor]

I will be opening my wire harness from cyl 3 coil all the way back to the ECU. The erratic behavior of the rough idle and running on 7 out of 8 and then going away by a key cycle and a 10 or so min stop leads me to this conclusion. That and I have already addressed every other variable. I'm hoping to find cracked wire insulation like on the old 1.8t. That or a bad ground, dirty connection, anything at this point. I will report back. I attached images of what used to cause this problem on the old 1.8t cars. Hoping this is it this time. There is so much heat under the hood from the turbos, this makes sense.https://uploads.tapatalk-cdn.com/20180224/452834049c864f92590fc32ef0ec2518.jpghttps://uploads.tapatalk-cdn.com/20180224/57bb2961db2dadae70b1e1990d0de955.jpg

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Hey Brian, did your issue come back?

[brian_216]

Hey Brian, did your issue come back?Yes. It is hit and miss again. Highway driving brings it on, usually 30 to 40 min into the drive. Flashing cel and misfire stored on cyl 3. I still didn't get to look at the harness, this weekend was bring the snowmobiles home from our camp upstate NY, and otherwise just busy. I'm hoping that this week I can get a look at the harness.

Anyone got a pinout of the harness at the ECU? I'm going to unplug it and the coil in question and find the wires going to the coil on cyl 3 to do an ohms test end to end. That may show a possibility of a broken wire or bad connection.

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[///M Traitor]

Yes. It is hit and miss again. Highway driving brings it on, usually 30 to 40 min into the drive. Flashing cel and misfire stored on cyl 3. I still didn't get to look at the harness, this weekend was bring the snowmobiles home from our camp upstate NY, and otherwise just busy. I'm hoping that this week I can get a look at the harness.

Anyone got a pinout of the harness at the ECU? I'm going to unplug it and the coil in question and find the wires going to the coil on cyl 3 to do an ohms test end to end. That may show a possibility of a broken wire or bad connection.

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Sorry to hear that man. I'm assuming you have already swapped coils in your original troubleshooting steps? I'm tempted to buy a new coil and throw it on a cylinder and see what happens in the "charts." RockAuto has two aftermarket brand coils for our car, and one of them claims to be an improvement over OEM. For $25, it might be worth it just for the data.

[Cris_OO7]

Any updates trying to solve CEL misfire issues?


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[///M Traitor]

I'm still experiencing misfires across all cylinders. They are not related to COD transitions as they can be felt when trying to make medium/high torque at mid RPM (well outside of 4-cyl mode territory). I am planing on continuing my logging experiment with adding a GDI valve cleaner treatment (sprayed into the intake) and plotting that change. As well as possibly replacing an ignition coil or spark plug on the most troubled cylinders...

[Dasquade]

I'm still experiencing misfires across all cylinders. They are not related to COD transitions as they can be felt when trying to make medium/high torque at mid RPM (well outside of 4-cyl mode territory). I am planing on continuing my logging experiment with adding a GDI valve cleaner treatment (sprayed into the intake) and plotting that change. As well as possibly replacing an ignition coil or spark plug on the most troubled cylinders...
Did you log your lambda sensors yet?
Same for checking your exhaust line (leakage)?
I had very simular issues as you. My downpipes bolts came loose. Tightened them. Felt much better but i really needed a fully warm engine. Few days ago i swapped to stock exhaust (with hidden cats), turned out 1 gasket between the downpipes and exhaust burned/broke the gasket. Now car is again perfect under every condition!
Worth checking imho....

[Cris_OO7]

Are u guys getting CEL and EPC with your misfires?


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[Tuner1]

Are u guys getting CEL and EPC with your misfires?


Sent from my iPhone using Audizine (http://r.tapatalk.com/byo?rid=87676)Depend when the misfire is continious then is flashing...

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[Tuner1]

Now i received a intern Audi Document from some collegue here is the issue of our misfires.... when the misfire continue with software update 003 on the rs6 than we have to do that changes....https://uploads.tapatalk-cdn.com/20180306/8600683a593eb3c5793f44f8ba0f7c32.jpg

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[mavpsire]

Now i received a intern Audi Document from some collegue here is the issue of our misfires.... when the misfire continue with software update 003 on the rs6 than we have to do that changes....https://uploads.tapatalk-cdn.com/20180306/8600683a593eb3c5793f44f8ba0f7c32.jpg

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Can you post a better picture of this document?

[Tuner1]

Can you post a better picture of this document?Here is it... the strange thing that only audi germany has this document, i asked at audi italy and they dont have it in the database... [emoji35]55581

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[Chris Morales]

What the heck does that say/mean?


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[Tuner1]

What the heck does that say/mean?


Sent from my iPhone using Audizine (http://r.tapatalk.com/byo?rid=87676)That we have to add from zylinder 5-8 this spacers under the valve springs on the exhaust side [emoji85][emoji85][emoji85] https://uploads.tapatalk-cdn.com/20180308/25f857bdcd2f843b18b73fb88139ee72.jpg

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[Hofahome]

I can't imagine Audi covering that without warranty.


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[mcouch70]

I wonder if it has something to do with spring tension or seating and the exhaust valves are either not seating or not closing fast enough under full load. It would be nice if we could get confirmation from someone else on this and finally put this thing to bed.

[Cris_OO7]

This is getting ridiculous. We nay have to get together and take this to court.


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[digdah]

In for us taking this to Audi and making them do what is right.

[mavpsire]

This also seems to be only for the RS6/7 Performance... ?

[Tuner1]

This also seems to be only for the RS6/7 Performance... ?The document i have only for rs6/7 amd s8 but i think that the problem is, that only that models comes already original ober the 750nm of torque.... and the problem is only when you come over that torque.... i tested on my rs6 over 30 maps and i saw, that when i limit the torque to 700nm from 5000-6000 U/min i dont have the misfires.....

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[mavpsire]

The document i have only for rs6/7 amd s8 but i think that the problem is, that only that models comes already original ober the 750nm of torque.... and the problem is only when you come over that torque.... i tested on my rs6 over 30 maps and i saw, that when i limit the torque to 700nm from 5000-6000 U/min i dont have the misfires.....

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Interesting - what about the stock map? Have you done any diagnosis on that as this has been documented as a problem from factory.

[Tuner1]

Interesting - what about the stock map? Have you done any diagnosis on that as this has been documented as a problem from factory.The problem started when i changed the downpipes.... also on stock map but with switched off lambdas i think because already there i had more than the 750nm...

I saw that apr had the same problem with a 2.0tfsi and changed the springs everything was solved....

Look here....
http://www.golfmkv.com/forums/showthread.php?t=183564

So i think on september (than i have time to open the engine) i change with the harder springs from LOBA


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[mcouch70]

Makes sense completely. Which is why tuning these cars exacerbates the issue. I doubt Audi would do much for our tuned cars since the oem set up seems to work okay for the stock map(under 700nm). Tuner1, please keep us posted if you change these out. Really curious at this point.

[Tuner1]

Makes sense completely. Which is why tuning these cars exacerbates the issue. I doubt Audi would do much for our tuned cars since the oem set up seems to work okay for the stock map(under 700nm). Tuner1, please keep us posted if you change these out. Really curious at this point.I change them sure because i hate this misfires... i switched off also the 4 cylinder mode and that helps a lot on cold start misfires

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[///M Traitor]

So what is it from? Excessive exhaust back-pressure holding open the exhaust valves?

[Dasquade]

In a way i think this indeed could be one of the reasons of the famous hidden (unfeelable) misfires.
Got my exhaist fixed and car been good ever since (beside one random CEL misfire on cylinder 8, it was on cold engine :s). Runs perfect but i keep logging misfires.
Since audi has it as a fix i think there is some value in it. Custom tune here and running around 880Nm here...
Not sure if it can be bad for the engine (maybe not really and can be considered as a "safety"?). Sadely this ins't something you can remove and replace easly :(.

[OlyS6]

Thought I'd share my results of cylinder misfire counts for the past 2,000 miles since going APR Stage 3 (3 data points for each cylinder). My overall impression are that the rates are fairly linear, with cylinder 1 being the only 1 that has had a bit of a rate increase during the past 1,000 miles. The graph below is when I started measuring total misfires shortly after going Stage 3 at about 18,000 miles. The second data point was at 19,000 miles, and the third data point was taken today at 20,000 miles. I have not had any CELs, nor have I noted any performance issues. I plan on continuing to log these every 1,000 miles to see if there is any increase in the rate of misfires (an increase in the slope of any of the lines), especially for cylinder 1 since it's showing a slight increase already. This may just be a boring observation and not important, but I don't think we really have a great handle on what 'normal' is for our cars, especially when tuned. I hope folks find these numbers reassuring, and that others continue to share theirs.

http://www.audizine.com/gallery/data/500/misfire_count.jpg

[1975audi]

Back in March when I took out my car from storage I started it up and had a very rough idle, the engine light came on and the epc light.
I scanned it and I got a multiple miss fire and miss fire on cylinder 5
The next day it started up fine, I thought it was old gas that caused it.
A month later same thing but I drove it for a block and back home on limp mode, scanned it and same thing miss fire on cylinder 5.
Later that same day I started it and it was fine until 2 weeks later when I got off the hwy and the car died and wouldn't start.
Flatbed to the dealership and they told me turbos blown
Do you think it's all related or is that a separate issue

[1975audi]

Back in March when I took out my car from storage I started it up and had a very rough idle, the engine light came on and the epc light.
I scanned it and I got a multiple miss fire and miss fire on cylinder 5
The next day it started up fine, I thought it was old gas that caused it.
A month later same thing but I drove it for a block and back home on limp mode, scanned it and same thing miss fire on cylinder 5.
Later that same day I started it and it was fine until 2 weeks later when I got off the hwy and the car died and wouldn't start.
Flatbed to the dealership and they told me turbos blown
Do you think it's all related or is that a separate issue

This all started after installing downpipes with no cats.
Could the downpipes actually cause miss firing ?

[low-profile]

Thought I'd share my results of cylinder misfire counts for the past 2,000 miles since going APR Stage 3 (3 data points for each cylinder). My overall impression are that the rates are fairly linear, with cylinder 1 being the only 1 that has had a bit of a rate increase during the past 1,000 miles. The graph below is when I started measuring total misfires shortly after going Stage 3 at about 18,000 miles. The second data point was at 19,000 miles, and the third data point was taken today at 20,000 miles. I have not had any CELs, nor have I noted any performance issues. I plan on continuing to log these every 1,000 miles to see if there is any increase in the rate of misfires (an increase in the slope of any of the lines), especially for cylinder 1 since it's showing a slight increase already. This may just be a boring observation and not important, but I don't think we really have a great handle on what 'normal' is for our cars, especially when tuned. I hope folks find these numbers reassuring, and that others continue to share theirs.

http://www.audizine.com/gallery/data/500/misfire_count.jpg

Excellent idea to establish a baseline.

[1975audi]

So does changing out the coils and plugs resolve the misfire problem or does it just lessen it.
Also where is coil/plug number 5, I might just change the one and see if the issue goes away

[OlyS6]

So does changing out the coils and plugs resolve the misfire problem or does it just lessen it.
Also where is coil/plug number 5, I might just change the one and see if the issue goes away

There are several lines of thought on this, and although I'm not an expert I'll share some of the reasoning as I understand it
1) Turbo powered cars generally need 'better' oil than others, which won't break down as readily as others. Many folks (including myself) feel that the factory recommendation of 10K oil changes is not nearly good enough. It seems like many folks with blown turbos have been sticking with factory recommendations, and often using Castrol oil that the dealerships are using. I have no firm evidence on this as a root cause, but you can find some interesting information out there on proper oiling of turbos. Check out silly rabbit motorsports and some links they have on their site. A potential way to mitigate this issue is to do oil changes every 5K (some folks at higher power levels are doing it even more often), and to use something like Motul 5W40 or similar (I own no stock in Motul).

2) The oil separators, with version 'B' or version 'D' are known to fail over time, and have been replaced with a part number ending in 'E'. One thought is that the oil separator may not be doing it's job properly for some time before it fully 'fails' causing the train whistle sound, which may be contributing to misfires and such. Not sure how much (if any) these faulty oil separators are contributing to turbo issues.

3) The turbo lines and the O-rings themselves on our cars are known to leak and cause a build-up of gunk over time in our cars. You can imagine that if any solid build-up of either coolant or oil sludge in any of the lines clogs up a line, that the turbos would likely fail secondary to 'starvation' of coolant and/or oil. Reading some of Brian's posts, I'm considering going back in and pulling my lines to at least examine them if not replace them, and to check out the check valve and screen beneath the turbos.

4) Dirty plugs and/or faulty coil packs can certainly lead to misfires, and would be a comparatively easy first step to try to lessen the rate of misfires in your car. It would be great if folks with new cars and low mileage were to log their total misfire counts so we can establish a baseline 'normal' for misfire rates in our engines, which may be attributed to the back-and-forth switching between 4 and 8 cylinder modes in our cars that have cylinder-on-demand.

**All of this is theory that has been tossed about on these threads, and I have no definitive proof for any of the above statements. I do feel, however, that some of the things I've mentioned above are prudent moves to protect our cars and our turbos, especially knowing that more folks are seeing issues. My fear is that this is all mileage related, as opposed to anything that is different across model years, so it may only be a matter of time before we start seeing these same issues cropping up on facelift cars as well.

[Hofahome]

Anyone else here feel stutter/misfire when you give it 75-100% throttle if the car is still cold (oil temp below about 160)?
I obviously dont regularly go wot on a cold motor but have had to a few times. Happened before my car was tuned too.


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[elptxjc]

Just as a side comment, now that I changed the oil for the first time (at 4,400 miles) with M1 0/40 (rather than the factory 5/40), due to a long trip last week, the engine is much quieter on cold starts. Don't think the turbos run dry in cold starts (an expert can confirm that), like the engine, but thinner oil lubricates everything much sooner, and might extend their life as well. I know group-III M1 is not the best oil you can find, but with 5K-mile intervals and no tracking, should be good enough IMO.

[brian_216]

There is yet another thing I dont think we have taken into account. What does our processor use to determine a misfire? Does it look at coil voltage after it fires or is it from the knock sensors? Any unwanted harmonic could trigger it if it were the knock sensor, such as a downpipe not secured to the transmission properly, a flange further down the exhaust path vibrating against something etc. Even a failing motor mount may be enough to cause it. Maybe one of the EPL guys can chime in and comment on just how the computer works when it comes to misfires.

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[kpriv]

There is yet another thing I dont think we have taken into account. What does our processor use to determine a misfire? Does it look at coil voltage after it fires or is it from the knock sensors? Any unwanted harmonic could trigger it if it were the knock sensor, such as a downpipe not secured to the transmission properly, a flange further down the exhaust path vibrating against something etc. Even a failing motor mount may be enough to cause it. Maybe one of the EPL guys can chime in and comment on just how the computer works when it comes to misfires.

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My guess is that the "unfeelable" misfires are somehow related to this. I have been logging my misfire counts and I have been very steady at ~225 per 1k miles on cylinder 5, ~125/1k on cyl 3, and 50 +/- on all other cylinders. This has been very consistent over the course of 8-10k miles. I have never felt a single one or had a flashing CEL. Moreover, I have logged misfires while doing a regular 45 min commute home in varying conditions (hwy, city streets, etc). Almost all of my logged misfires are occurring at relatively low RPM in low-load situations. As I've mentioned before on the forum, I have yet to log a misfire at WOT. However, I have logged a misfire immediately after letting off the throttle on a WOT run. This makes sense to me as a vibration being picked up as a misfire as everything slows down.

Like oly mentioned earlier -- this is purely conjecture on my part. I plan to switch plugs in the next few months and will line them all up to see if I can see any difference in how 5 & 3 look vs. the others.

[Dasquade]

There are several lines of thought on this, and although I'm not an expert I'll share some of the reasoning as I understand it
1) Turbo powered cars generally need 'better' oil than others, which won't break down as readily as others. Many folks (including myself) feel that the factory recommendation of 10K oil changes is not nearly good enough. It seems like many folks with blown turbos have been sticking with factory recommendations, and often using Castrol oil that the dealerships are using. I have no firm evidence on this as a root cause, but you can find some interesting information out there on proper oiling of turbos. Check out silly rabbit motorsports and some links they have on their site. A potential way to mitigate this issue is to do oil changes every 5K (some folks at higher power levels are doing it even more often), and to use something like Motul 5W40 or similar (I own no stock in Motul).

2) The oil separators, with version 'B' or version 'D' are known to fail over time, and have been replaced with a part number ending in 'E'. One thought is that the oil separator may not be doing it's job properly for some time before it fully 'fails' causing the train whistle sound, which may be contributing to misfires and such. Not sure how much (if any) these faulty oil separators are contributing to turbo issues.

3) The turbo lines and the O-rings themselves on our cars are known to leak and cause a build-up of gunk over time in our cars. You can imagine that if any solid build-up of either coolant or oil sludge in any of the lines clogs up a line, that the turbos would likely fail secondary to 'starvation' of coolant and/or oil. Reading some of Brian's posts, I'm considering going back in and pulling my lines to at least examine them if not replace them, and to check out the check valve and screen beneath the turbos.

4) Dirty plugs and/or faulty coil packs can certainly lead to misfires, and would be a comparatively easy first step to try to lessen the rate of misfires in your car. It would be great if folks with new cars and low mileage were to log their total misfire counts so we can establish a baseline 'normal' for misfire rates in our engines, which may be attributed to the back-and-forth switching between 4 and 8 cylinder modes in our cars that have cylinder-on-demand.

**All of this is theory that has been tossed about on these threads, and I have no definitive proof for any of the above statements. I do feel, however, that some of the things I've mentioned above are prudent moves to protect our cars and our turbos, especially knowing that more folks are seeing issues. My fear is that this is all mileage related, as opposed to anything that is different across model years, so it may only be a matter of time before we start seeing these same issues cropping up on facelift cars as well.

For what it is worth, S6 C7 2013 with 85.000km on it. I replaced my coolant in and oil in seals a good week ago. Especially the coolant seal had visually small cracks in it and was compresed/baked in shape so that obviously didn't seal properly anymore. BUT the inside of turbo (where the lines go in) was perfect clean....so i guess coolant only starts to cook and make that famous crumble carbon once in concat with air and extreme heat?
Still need to find a way to loosen the coolant out lines....

[Hofahome]

I actually have blown engine mounts per vcds, just need to take the car in. I could take a few before and after logs of misfires and see if there is any correlation.


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[Tuner1]

Interesting - what about the stock map? Have you done any diagnosis on that as this has been documented as a problem from factory.Hi mavpsire why i can not write you in private??

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[mavpsire]

Hi mavpsire why i can not write you in private??

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I'm not sure... ? but I am here!

Update: I have not had the flashing CEL or solid CEL light on since summer started....but I am now getting what feels like misfires when the car idles. Plugs were changed a week ago as part of the 55,000km service. Feelable misfires continued even on the new plugs.

[CJ_S4]

Sign me up for the rough pull and shudder from 2500-4000 rpm under 75% or more load (high torque, high load, relatively low rpm conditions). I haven't been able to log misfires, but suspect I'm having the same issues.

Are there any resolutions to this issue yet? The ECU firmware update? The exhaust valve spring spacers?

[///M Traitor]

I'm still having the misfires as well. I had gotten too busy to stay on top of the logging, etc. But the misfires are getting worse for me. I checked back on this thread today to see if anyone figured it out :-P

[///M Traitor]

There is yet another thing I dont think we have taken into account. What does our processor use to determine a misfire? Does it look at coil voltage after it fires or is it from the knock sensors? Any unwanted harmonic could trigger it if it were the knock sensor, such as a downpipe not secured to the transmission properly, a flange further down the exhaust path vibrating against something etc. Even a failing motor mount may be enough to cause it. Maybe one of the EPL guys can chime in and comment on just how the computer works when it comes to misfires.

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An Audi technician who I trust told me that the computer uses RPM information to determine misfires. When there is a sudden change, or decrease in rate of crank rotational acceleration which is unexpected, it properly registers that as a misfire. I have no doubt that what I am feeling is a miss, and the computer is picking it up properly.

What I can’t figure out is why everybody has different problematic cylinders. Could it be the injectors - which are impossible to get to?

[brian_216]

An Audi technician who I trust told me that the computer uses RPM information to determine misfires. When there is a sudden change, or decrease in rate of crank rotational acceleration which is unexpected, it properly registers that as a misfire. I have no doubt that what I am feeling is a miss, and the computer is picking it up properly.

What I can’t figure out is why everybody has different problematic cylinders. Could it be the injectors - which are impossible to get to?Nope. I changed the injector on my problem cylinder and the problem came back. So its not the ignition coil, not the injector. But the plug will end up being black and fouled when you pull it after the misfiring continues long enough. Could be something mechanical that we cant see. Like a heat degraded wiring harness between the ECU and the coil, or stuck rings causing blow by and low compression. It's too weird that nobody has put their finger on this yet.

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[///M Traitor]

Nope. I changed the injector on my problem cylinder and the problem came back. So its not the ignition coil, not the injector. But the plug will end up being black and fouled when you pull it after the misfiring continues long enough. Could be something mechanical that we cant see. Like a heat degraded wiring harness between the ECU and the coil, or stuck rings causing blow by and low compression. It's too weird that nobody has put their finger on this yet.

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Could it be the exhaust valve issue since it's so random by cylinder?

[///M Traitor]

I purchased a coil pack for an RS7 to try in my problematic cylinder #2 which is relatively easy to get to compared to the drivers-side bank. I don’t think this will “fix” the underlying problem. But the hotter spark of the RS ignition pack may help overcome whatever is ailing that cylinder.. I’m going to add a datapoint to my misfire chart so we can see the change after changing the pack.

I should note, I swapped cylinder 1 & 2 coil packs with absolutely no change. Cylinder 2 continued with the same misfire rate.

[CJ_S4]

Bumping...

I'm considering swapping to RS7 OEM plugs. Thoughts?

[kpriv]

Bumping...

I'm considering swapping to RS7 OEM plugs. Thoughts?

Yes when it’s time for new plugs, but not to solve this. For the past 10k miles, the misfire rate by cylinder in my car has not changed. Cyl 5 shows about 4x as many as the other cylinders, cyl 3 about 2x as many, and all the rest are about 50 / 1k miles.

Over that period I’ve ran:
- stage 2 tune 93 and 91
- flashed completely to stock
- e25 blend
- pump 91 e10
- stock S turbos
- stage 3 with rs turbos, RS coils, and the new “M” plugs (which are now the OE plugs for all 4.0T variants)
- COD enabled and disabled
- had an ECM update from “s001” to “s002” to see if it was baseline software related

No change in any of these scenarios. I’ve never felt any of the misfires, the car performs great at WOT. Logging over long periods of varied driving they show up at random times. Based on this, it is my hypothesis that these are not true misfires but rather sensor sensitivity. Maybe that is incorrect and I’m fooling myself, but it seems like every car has the “misfires” — even those with no other symptoms and which have no physical manifestation of an actual problem.

My takeaway: I’m no longer concerned until I have an actual issue with the way the car performs. And I wouldn’t bother changing your plugs unless it is time to do so.



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[CJ_S4]

Yes when it’s time for new plugs, but not to solve this. For the past 10k miles, the misfire rate by cylinder in my car has not changed. Cyl 5 shows about 4x as many as the other cylinders, cyl 3 about 2x as many, and all the rest are about 50 / 1k miles.

Over that period I’ve ran:
- stage 2 tune 93 and 91
- flashed completely to stock
- e25 blend
- pump 91 e10
- stock S turbos
- stage 3 with rs turbos, RS coils, and the new “M” plugs (which are now the OE plugs for all 4.0T variants)
- COD enabled and disabled
- had an ECM update from “s001” to “s002” to see if it was baseline software related

No change in any of these scenarios. I’ve never felt any of the misfires, the car performs great at WOT. Logging over long periods of varied driving they show up at random times. Based on this, it is my hypothesis that these are not true misfires but rather sensor sensitivity. Maybe that is incorrect and I’m fooling myself, but it seems like every car has the “misfires” — even those with no other symptoms and which have no physical manifestation of an actual problem.

My takeaway: I’m no longer concerned until I have an actual issue with the way the car performs. And I wouldn’t bother changing your plugs unless it is time to do so.



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Good stuff, Thanks for the reply. I wonder since I'm experiencing the stutter (I can't even really call it misfire, since I haven't logged) under load if it would help. Sure seems like a back-pressure issue spooling the turbos around 2500 rpm, because over 4100 rpm it gets its shit together and pulls hard.

I don't have any explanation as to why new spark plugs would solve this, it would just be pretty much a shot in the dark to see if there is any improvement.

[Tuner1]

Hi guys
Also some news from me i programmed out completely the knock sensors for test and misfire is still there so lets continue to search ....

Rs6 Performance, Catless Downpipes, Straight Exhaust, Loba High Fuel Pumps, Forge Intercooler, Arma Intake ....

[AUDIFREAK23]

I purchased a coil pack for an RS7 to try in my problematic cylinder #2 which is relatively easy to get to compared to the drivers-side bank. I don’t think this will “fix” the underlying problem. But the hotter spark of the RS ignition pack may help overcome whatever is ailing that cylinder.. I’m going to add a datapoint to my misfire chart so we can see the change after changing the pack.

I should note, I swapped cylinder 1 & 2 coil packs with absolutely no change. Cylinder 2 continued with the same misfire rate.

I thought I was the only one....So glad I found this thread. Ive tried new coils and plugs...no change. M Taritor, you discribe the EXACT issue Im having. IVe had my13 for a little over 2 yrs and this issue is beginning to make me hate the car. I just want this fixed

[Mokacrow]

That we have to add from zylinder 5-8 this spacers under the valve springs on the exhaust side [emoji85][emoji85][emoji85] https://uploads.tapatalk-cdn.com/20180308/25f857bdcd2f843b18b73fb88139ee72.jpg

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HEY TUNER1

Running into this issue now with a 13 S6 and wondering if these spacers provided a fix? If so, do you have a part number for them?

[Tuner1]

HEY TUNER1

Running into this issue now with a 13 S6 and wondering if these spacers provided a fix? If so, do you have a part number for them?Hi i dont made the test at the moment.... we are making some other tests next month

Rs6 Performance, Catless Downpipes, Straight Exhaust, Loba High Fuel Pumps, Forge Intercooler, Arma Intake ....

[prosier]

Any new results about the misfires here?

[Tuner1]

Any new results about the misfires here?Hi i received the harder valve springs... i let you know when i mounted them....

Rs6 Performance, Catless Downpipes, Straight Exhaust, Loba High Fuel Pumps, Forge Intercooler, Arma Intake ....

[Mokacrow]

Hi i received the harder valve springs... i let you know when i mounted them....

Rs6 Performance, Catless Downpipes, Straight Exhaust, Loba High Fuel Pumps, Forge Intercooler, Arma Intake ....



Can you tell me if you have any documentation from Audi? i'm assuming that your location is correct and you are in Italy. Audi of North America has yet to acknowledge this problem.

I'm curious if you received harder exhaust valve springs, or just spacers to make the spring stronger. Either way, it seems like the springs aren't strong enough to deal with the vibrations, at those RPMS.

Cheers

[Mokacrow]

Also, do you have a part number????

[Tuner1]

Can you tell me if you have any documentation from Audi? i'm assuming that your location is correct and you are in Italy. Audi of North America has yet to acknowledge this problem.

I'm curious if you received harder exhaust valve springs, or just spacers to make the spring stronger. Either way, it seems like the springs aren't strong enough to deal with the vibrations, at those RPMS.

CheersWrite me a PM so i tell you the parts that i ordered...

Rs6 Performance, Catless Downpipes, Straight Exhaust, Loba High Fuel Pumps, Forge Intercooler, Arma Intake ....

[slowguy]

Add me to the list of misfire group. I logged slight misfires via vcds. Never a flashing cel. Just over 100k miles, ‘13 s6 stage 2, stock everything. Occasionally runs very slightly rough on cold start, I also have a code for engine mount but no other codes, ever. I can feel the slight miss on 50-75% medium accelerating only. Never really felt it at wot. Changed all to ngk plugs, all coil packs to rs7 variant. I’ll do the pcv procedure and screen this spring or summer but never had the noise or code for a failure.

I have a very smart mechanic friend who votes for carbon from the direct injection....especially if the pcv has not properly or fully been doing it’s job. I ran a couple of cans of di cleaner through the intake and it did seem to “feel” a little smoother but I didn’t log. I’ll run a few more cans through this spring and if I can scope the intake valve stems when I have the intercooler out for the pcv update I’ll check for carbon build up. I’ve read that if the build up is bad, di cleaner won’t do much in even a few applications. May take many tries or even mechanical cleaning (which we know, on these engines, would take an engine pull)

Definitely subbed on this one. Would be worth money here to find an answer :)

[Hugson]

Same issue by me but not exactly.

I have stage 2 S8 with custom downpipe - no cats and also without 2 lambda's in it. They are plugged but outsite downpipe. Sometimes get CEL but only 2 errors about poor fuel ( that's normal when lambdas are outside downpipe ). I tryed to fix that random CEL problem by perform slots in real downpipe area. No more CEL about poor fuel, it was clean on VCDS but... after 20-30 miles,
and 100% throttle opening got flashed CEL and multipe missfires on 1,5,6 bank. After that I again unscrew 2 lambdas ( after cats in stock for certainty ) and problem with flashing CEL and misfires gone away.
Still thinking how to solve that random CEL with poor fuel on secounds lambdas. By the way my car has all the time rough idle rpm. I just think that is problem with custom downpipes without cats... but it's additional ~40 HP tested on dyno :)

Hope that someone centainly fix that problem :)

Also found that info here:

https://www.audizine.com/forum/showthread.php/847519-4-0-TFSI-Misfire-and-problems

Think that is really intresting.

[Tuner1]

Same issue by me but not exactly.

I have stage 2 S8 with custom downpipe - no cats and also without 2 lambda's in it. They are plugged but outsite downpipe. Sometimes get CEL but only 2 errors about poor fuel ( that's normal when lambdas are outside downpipe ). I tryed to fix that random CEL problem by perform slots in real downpipe area. No more CEL about poor fuel, it was clean on VCDS but... after 20-30 miles,
and 100% throttle opening got flashed CEL and multipe missfires on 1,5,6 bank. After that I again unscrew 2 lambdas ( after cats in stock for certainty ) and problem with flashing CEL and misfires gone away.
Still thinking how to solve that random CEL with poor fuel on secounds lambdas. By the way my car has all the time rough idle rpm. I just think that is problem with custom downpipes without cats... but it's additional ~40 HP tested on dyno :)

Hope that someone centainly fix that problem :)

Also found that info here:

https://www.audizine.com/forum/showthread.php/847519-4-0-TFSI-Misfire-and-problems

Think that is really intresting.We have all the same problems with the misfires..they starts at ca. 5500rpm in up... i think i found also the problem why it starts to misfire, i changed my software so that i can bring them out also with the original downpipes ... is a hardware thing.... but i tell you more when im 100% sure... it will be in a 2 month when i have all the parts in house

For you as info;
I changed coils,3 types of sparks, various types of exhaust (xpipe and hpipe) racing fuel, i switched off knocking sensors to test ecc the misfire are hardware based im sure that soon i have the solution....

Have a nice evening

Rs6 Performance, Catless Downpipes, Straight Exhaust, Loba High Fuel Pumps, Forge Intercooler, Arma Intake ....

[Hugson]

So you tested it also on stock downpipe and it's not solve problem ?
I just thinking about stock downpipes but think it's not good way.
I don't get missfire exactly but only have problem with rough idle.
It's a way to reset in VCDS misfires counter ?

So you tested it also on stock downpipe and it's not solve problem ?
I just thinking about stock downpipes but think it's not good way.
I don't get missfire exactly but only have problem with rough idle.
It's a way to reset in VCDS misfires counter ?

Also get engine mount error, it will be replace in few days and inform here about results, but I am sure that not solve problem.

[Tuner1]

Yes with vcds you can reset the counter is in the engine module "reset all learned values" a option called something like this i have it in german

With original downpipe you solve it yes but only because you have lesser power with them...

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[Hugson]

Got some information about exhaust :)

Yesterday morning after night with cold engine start 120 km trip for exhaust replace.
After 120 km get missfires like on photo, then install new full custom exhaust MG Motorsport with new downpipes, cells, mufflers - 100% custom.
Next after 6 hours of exchange my old exhaust with only custom downpipes I come back to home same way 120 km, and you can see on photo results.
I can confirm that engine work better, specially on idle. No rough like before with old exhaust. Also check missfires today after next 100 km.
It seems that now works like if should work.

Maybe someone can check for me how many missfires get on stock 4.0T from 100 km~ ?

https://i.ibb.co/XysQNpN/S8-missfires.jpg

[CJ_S4]

Updating the community:

I had the factory spark plugs replaced with RS7 spec spark plugs (06K 905 601M) at my last service (oil change) at 28,500 miles.

Can report that overall, the high load/low rpm stutter between ~2,700-4,100 rpm is not gone, but noticeably better. Boost seems to build better, and there is less overall hesitation.

2016 MY (and perhaps other) 4.0T engines call for spark plugs to be replaced at 35,000 miles or 6 years which ever is first.

[jgoldstein2000]

For those still following this thread here are my misfires on a 2018 s7 for last 1500 miles or so. 121370


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[jgoldstein2000]

Maybe 1000 miles


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[SmithComm23]

Add me to the list. I've got a 2013 S8. Problem started on stage 1. A few times on start up blinking CEL. Turned off then back on fine. Until completely gave up on starting. It was plastic intake on passenger side shearing off and plastic damaging the passenger turbo wheel. I removed them and had comp turbo rebuild them both. I reinstalled and ran great for about 6 months. It happened again with cel flashing on startup and rough shuddering. Turned off then on, issue went away. 1 month later went stage 2 with APR tune and high flow APR copy cat dp's. Within 2 days, same issue on startup. Turned off then on it was ok. Then I started noticing same jerking or shuddering others in here mentioned. I'm have the misfires on 1,5,8. 8 being the worst. I moved the plug and coil to 7 from 8 and misfires moved to 7. I thought I dodged a bullet. I replaced plugs and coils on 5,6,7,8. Problem seemed to be fixed. Ran great a few days, then I could feel it coming back. I replaced plugs and coils 1,2,3,4. Test drove with no issues. Parked in my garage, went out 2 hours later and severe misfiring on startup, cel flashing, code for random,multiple, and misfire 1, 5, 8. 1 week ago I checked the turbo wheels and they looked good, no contact, spin nicely, very little play. Sometimes the car runs perfect and other times it runs like shit. This car is an emotional roller coaster. I love my car, but I'm losing hope especially after reading numerous threads with no answer.

[Dasquade]

Add me to the list. I've got a 2013 S8. Problem started on stage 1. A few times on start up blinking CEL. Turned off then back on fine. Until completely gave up on starting. It was plastic intake on passenger side shearing off and plastic damaging the passenger turbo wheel. I removed them and had comp turbo rebuild them both. I reinstalled and ran great for about 6 months. It happened again with cel flashing on startup and rough shuddering. Turned off then on, issue went away. 1 month later went stage 2 with APR tune and high flow APR copy cat dp's. Within 2 days, same issue on startup. Turned off then on it was ok. Then I started noticing same jerking or shuddering others in here mentioned. I'm have the misfires on 1,5,8. 8 being the worst. I moved the plug and coil to 7 from 8 and misfires moved to 7. I thought I dodged a bullet. I replaced plugs and coils on 5,6,7,8. Problem seemed to be fixed. Ran great a few days, then I could feel it coming back. I replaced plugs and coils 1,2,3,4. Test drove with no issues. Parked in my garage, went out 2 hours later and severe misfiring on startup, cel flashing, code for random,multiple, and misfire 1, 5, 8. 1 week ago I checked the turbo wheels and they looked good, no contact, spin nicely, very little play. Sometimes the car runs perfect and other times it runs like shit. This car is an emotional roller coaster. I love my car, but I'm losing hope especially after reading numerous threads with no answer.

What plugs are you running and how many miles/km on them?
*holding wood, but my misfires/stutter went away once i modified my non res milltek from stock H to X pipe in combination with from race plugs (though they were recommanded) back to stock M plugs. I still log virtual misfires, but no noticable misfires.

[SmithComm23]

Ok,
Plugs are NGK #06k-905-601M
They were new in December but I just put a full new set on 2 days ago. Gapped .024

I also replaced coil packs with the latest version from dealer.

After replacing. I cleared codes, drove with vcds in passenger seat trying to get a misfire and didnt have any. Turned it off, 2 hours later, cant even run the motor its misfiring so bad and cel flashing.

[Dasquade]

Ok,
Plugs are NGK #06k-905-601M
They were new in December but I just put a full new set on 2 days ago. Gapped .024

I also replaced coil packs with the latest version from dealer.

After replacing. I cleared codes, drove with vcds in passenger seat trying to get a misfire and didnt have any. Turned it off, 2 hours later, cant even run the motor its misfiring so bad and cel flashing.
Doesn't sound good :s no faults what so ever?

[SmithComm23]

Doesn't sound good :s no faults what so ever?


Random and multiple misfire po300
Misfire cyl 1
Misfire cyl 5
Misfire cyl 8

[scott99c2]

Any updates here?

[1975audi]

Driving today I gave the car half throttle and after it dropped gears and felt the boost the car made a thump and I lost power.
The car was still running, engine light was flashing but I had 0 power with the gas pedal.
I pulled over and put the car in park.
Instantly the check engine light stopped flashing, I then put it and drive and it drove normal all the way to work.
Got to work and scanned it
I got RANDOM MISSFIRE
and cylinder 8 detected missfire.


I already replaced turbos with the SRM and I'm stage 3 unitronic.
Any thoughts??138857138858

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[15 Phantom S6]

^^ did you change plugs when you went stage 3 and if so, what did you gap them at, I hope not OEM spec?

[1975audi]

The dealership did the 125klm service about a month ago, so ya it's gapped at OEM spec

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[15 Phantom S6]

Stage 3 requires a tighter gap on the plugs than OEM spec.. My bet is the OEM gap size is the cause of your misfiring..

I know you have Unitronic software, but for stage 3 with APR tune, APR states: "APR's software is designed for use with NGK heat range 8 spark plugs gapped to 0.024" ±0.002" or 0.6mm ±0.05mm with a change interval of 10-15,000 mi or 16-24,000 km"

latest spec of OEM plugs work fine, but the gap needs to be adjusted accordingly..

[1975audi]

Thank you sir.
I'll have to make time to re gap all of them.
Hopefully it's not to involved.

Sent from my SM-G955W using Audizine mobile app (http://r.tapatalk.com/byo?rid=87676)

[CJ_S4]

Was watching a random youtube video and came across a part of a repair/inde shop in Chicago that had a 4.0T car in there for blown turbos (oil screen), but he also talks about something else he was fixing that was leading to a misfire that was very hard to diagnose - looks like the crankcase valve.

Has anyone considered this to be causing misfires or throwing codes?

https://youtu.be/EZlvHiqFpr0?t=1307

[Mathews]

Was watching a random youtube video and came across a part of a repair/inde shop in Chicago that had a 4.0T car in there for blown turbos (oil screen), but he also talks about something else he was fixing that was leading to a misfire that was very hard to diagnose - looks like the crankcase valve.

Has anyone considered this to be causing misfires or throwing codes?

https://youtu.be/EZlvHiqFpr0?t=1307

Usually PCV failure symptoms an audible high-pitch whistling sound. Can't say I've heard it cause misfires before.

[CJ_S4]

Usually PCV failure symptoms an audible high-pitch whistling sound. Can't say I've heard it cause misfires before.

As noted in the video the cars with the 4.0T with the "hot V" setup the PCV and intake manifold sits under the turbos.

For NA cars, this whistling sound may be the usual diagnosis, but with the intake manifold (and pcv valve) sitting below the turbos this may change the mechanism by which this problem manifests itself.

He also goes on to say that the problem with the PCV leads to a "hard to diagnose" misfire that isn't logged to a specific code - like many of the misfire issues in this thread.

With the PCV being in close proximity to the intake manifold it seems plausible that this could be related to a misfire, but someone with more knowledge than me about how our specific PCV/intake manifold works will need to corroborate that.

[Dasquade]

Not sure what the link between both parts could be and never heard of it aswell...but curious if that indeed could be something.
*still having slight misfiring under semi boost when going around the 4000rpms...4000rpms the magic line when oil pressure valves open etc (forgot the details but things happen around 4000rpm line).
Mine seperator is still the stock one and didnt replaced yet as i dont have the squeel issue or pressure issues (afaik). No do i have oil consumtion issue.

[Dasquade]

Made me wonder....if the oil seperator would had issue it would be an vacum/air leak afaik and letting extra air into the manifold/cilinders.....shouldn't one be able to see that on the long and short fuel trims? Yeah, been learning myself bit more into those and didn't knew they were so important in properly diagnoting issues or at least they point you in a certain direction.
*will be adding long and short fuel trims to my gauge and do some testing....
My stutter kinda came back again sadely but still bang on the 4.000rpm under low throttle building up boost. No errors at all....

[CJ_S4]

Made me wonder....if the oil seperator would had issue it would be an vacum/air leak afaik and letting extra air into the manifold/cilinders.....shouldn't one be able to see that on the long and short fuel trims? Yeah, been learning myself bit more into those and didn't knew they were so important in properly diagnoting issues or at least they point you in a certain direction.
*will be adding long and short fuel trims to my gauge and do some testing....
My stutter kinda came back again sadely but still bang on the 4.000rpm under low throttle building up boost. No errors at all....

This is exactly what I'm talking about. I just don't know how it all works. The guy in the video says the pcv acts up and causes misfires but the ECU doesn't attibute it to a "lean code". So maybe his implication there is it is leaning out the air/fuel mix and causing misfires, but the computer doesn't know it?

It's a path worth exploring I think.

[Dasquade]

For what it is worth....did the long znd short fuel mixture trims on both banks this morning to work, glad to see my long trims where as good as always 0%. Short trims also most of the times bang on 0% with small spikes perfectly within tolerances of -10/+10% witch is fine. Only when i let go of the trotthle it the short trims spike a bit till -20/-25%...but i blame that on my tune (extra burble tune). "Sadely", even tough i tried to trigger my stutter when still semi cold, it didnt stuttered (typicly haha)...but i figured since it often did it in the past it would have showed on the long trims as it had learned to compensate....but not.

Still curious what exactly the pvc's role could be in the hidden misfires (altought i still think vacum/pressure leak is what they meant and again think normally it should show up in the long trim. Might log the o2 sensors...

[Dasquade]

After talking about it with a friend, he suggested to look into the spark/coil plug wires...a cable breatch normally also dont show up as error and could explain the randomess altought still strange it always happens at the magic 4000rpm line under very specific throttle input.

[Reverie]

When you consider that the engine fires fifty times each second, or whatever, isn't several hundred misfires over the course of thousands of miles fairly insignificant?

[Wkraus]

Does anyone have an update on this? Part numbers that work if so? Thanks!

[Dasquade]

Does anyone have an update on this? Part numbers that work if so? Thanks!
In my case i can just say....installed DS1 OTS stage 2 and it updated my ECU software from 0009 too 0012 and car runs PERFECT NOW!!
Not sure if it was due to old software where my previous tune was based on or the tune it self. Fact is i had the 4.000 build up boost issue on stage 1 and stage 2 (with dyno runs etc). All i know i have a new car (bit less power but rather slower car and overall better performing).
Wish i had DS2 logger and could of compaired the old tune (i'm sure the logger would of shown what was not okey i think).
*yes still getting (unnoticeble) misfires in the fis logger, but those are 'normal' cold start and random ones...

[JustinT]

For those still following, I have a misfire mainly on cyl 1 and 5 which occurs most often on the first acceleration after the car's been started from cold and warmed up for ~5min in the garage. Below are some facts,

- 45837mi on the odometer, completely stock car.
- The misfire is only under very low load/throttle and at ~1500RPM and can be felt by the driver.
- The total number of misfires per cylinder 1/2/3/4/5/6/7/8 is: 3929/418/1098/448/3234/1690/1148/271

Anyone have something similar or have ideas what I could check?

[Dasquade]

For those still following, I have a misfire mainly on cyl 1 and 5 which occurs most often on the first acceleration after the car's been started from cold and warmed up for ~5min in the garage. Below are some facts,

- 45837mi on the odometer, completely stock car.
- The misfire is only under very low load/throttle and at ~1500RPM and can be felt by the driver.
- The total number of misfires per cylinder 1/2/3/4/5/6/7/8 is: 3929/418/1098/448/3234/1690/1148/271

Anyone have something similar or have ideas what I could check?
Did you tried look into disabling the start/stop feature?
Worth checking it out if it helps you.

[JustinT]

Did you tried look into disabling the start/stop feature?
Worth checking it out if it helps you.

Fortunately/unfortunately no stop/start function on my 2015 model year car.

[WmRS3]

No fix to this I bought a 2017 S8 and it’s missing all over dam.

[Woodepic]

I have a similar problem, potentially caused by a problem with the PCV as discussed above. All I know for sure right now is that I'm getting misfires due to oil on the spark plugs / oil in the intake manifolds.

If you've had a similar situation or think you can help, please check out my thread!
https://www.audiworld.com/forums/s7-197/cyl-8-misfires-oil-spark-plug-electrodes-3043734/

[vrod]

I know this thread is old but I am looking for someone whi I might be able to compare my S6 to? I have driven a lot in it, currently it has almost 197kkm on the counter. Over the last 5500km I have gotten 4x Cyl 8 random misfire. The 3rd time it caused the EPC light to go on. All 4 times the issue resolved itself.

Changed the coil for Cyl 8 yesterday, when pulling it out the rubber came apart and it was very well stuck in there. Afterwards I did a 30-40km test-drive and all smooth. I also have significant amounts of misfires on 2 and 5, 7 a bit as well. I am starting to think that the misfires on 2,3,5,8 are just a result of the CoD feature?

Would anyone have a 4.0T car with similar mileage and could let me know their amount of misfires?

[AuriuX]

I know this thread is old but I am looking for someone whi I might be able to compare my S6 to? I have driven a lot in it, currently it has almost 197kkm on the counter. Over the last 5500km I have gotten 4x Cyl 8 random misfire. The 3rd time it caused the EPC light to go on. All 4 times the issue resolved itself.

Changed the coil for Cyl 8 yesterday, when pulling it out the rubber came apart and it was very well stuck in there. Afterwards I did a 30-40km test-drive and all smooth. I also have significant amounts of misfires on 2 and 5, 7 a bit as well. I am starting to think that the misfires on 2,3,5,8 are just a result of the CoD feature?

Would anyone have a 4.0T car with similar mileage and could let me know their amount of misfires?

Hi,
My A8 4.0T has 198k km and started to get sometimes random misfires and one time EPC light, the fauls were Cyl.8, Cyl.3, one time Cyl.2 and all of that misfires i saw when coming from 4 cyl mode to 8 cyl mode and after longer highway drive.
My misfire counter shows: Cyl1 - 3412, Cyl2 - 3195, Cyl3 - 6476, Cyl4 - 1358, Cyl5 - 5907, Cyl6 - 4868, Cyl7 - 880, Cyl8 - 4209.
Few weeks now did not had any misfires..
The car is stock, thinking of doing stage1 and removing COD function.
Doing now BG fuel treatment and in a few weeks will do BG oil treatment.