Misfiring 3.0TFSI

[Westyfield2]

So today whilst driving it developed a bad misfire. Car was in Dynamic at the time, and being driven full throttle. Error message on the dash was EPC, but it wasn't serious enough for it to say "Stop Now".
Stopped the car at the services. Popped the bonnet and nothing obviously wrong. Turned the car off and on again. Misfire was gone, drove home perfectly.

VCDS scan below. Ignore the over-rev warning - that's after the misfire has started and is me putting the car in neutral and revving it (was afraid it was going to stall).

Does anyone have any ideas? Turning it off and on again worked, but why?!

-------------------------------------------------------------------------------
Address 01: Engine (J623-CGWB) Labels: 06E-907-551-CGW.clb
Part No SW: 4G0 907 551 F HW: 4H0 907 551
Component: 3.0l V6 TFSIH07 0005
Revision: --H07---
Coding: 12250034052701020000
Shop #: WSC 02311 785 00200
ASAM Dataset: EV_ECM30TFS0214G0907551F 001005
ROD: EV_ECM30TFS0214G0907551F.rod
VCID: 2C57F9C547FE635EF2-8078

5 Faults Found:
6353 - Cylinder 4
P0304 00 [096] - Misfire Detected
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 64802 km
Date: 2016.08.12
Time: 14:07:20

6354 - Cylinder 5
P0305 00 [096] - Misfire Detected
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 64802 km
Date: 2016.08.12
Time: 14:07:20

6371 - Random/Multiple Cylinder Misfire Detected
P0300 00 [096] - -
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 64802 km
Date: 2016.08.12
Time: 14:07:20

11837 - Maximum Engine Speed Exceeded: Engine Warranty VOID!
P0219 00 [096] - -)
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 64804 km
Date: 2016.08.12
Time: 14:08:32

7948 - Cylinder Disabling
P130A 00 [096] - -
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 64802 km
Date: 2016.08.12
Time: 14:07:20

Readiness: 0000 0000

-------------------------------------------------------------------------------

[gk1]

There is a laundry list of things that can cause a misfire.
Bad gas
bad coilpack
spark plugs
vacuum problems
emission systems problems (purge valve)
Since it only happened once I would clear and wait for it to happen again.

[sciblades]

why did it over rev?? did your trans mess up?

[DGVR6]

Is that even possible on neutral?

[Westyfield2]

What I don't understand is why the misfire was on two cylinders; 4 and 5.

• There's a list of things that will affect a single cylinder. E.g. an injector, a spark/coil. But this was two cylinders, not one.
• There's a list of things that will affect three cylinders. E.g. a camshaft position sensor. But this wasn't a whole bank, it was only two cylinders.

And then, why did turning it off and on again magically fix it?
If it was bad fuel, surely it would have happened again on the rest of the journey?


To those asking about the over-rev, don't worry about that. I know what it is.
If you look at the timestamp, it's a minute after the misfire has started. What happened was the traffic slowed down, and the engine was misfiring so badly that it felt like it was going to stall or cut out. So I stuck the gearbox into manual mode and kept the revs up high'ish, to keep it alive. But then the traffic slowed down further, so I shifted into neutral (forgetting that the car has the limiter set much lower in neutral). So as the car had come from high'ish-revs in a low gear, when I shifted into neutral it was above the neutral rev limiter (3000RPM or whatever it is), and the limiter instantly cut in dropping the engine down to 3000RPM. And because it had arrived in neutral with the revs at 5000RPM, it logged an over-rev.

[gk1]

I assume this is not your first Audi or VAG product since you have VCDS?
Misfires and in your case a cylinder disable always resets after a restart. Nothing is really "fixed" and the faults are not cleared just the system gives another chance to see if the issue is no longer occurring after restart. Almost all modern cars are this way. And in your case the system no longer had an issue.
The issue you felt really wasn't the single misfire. They happen from time to time and no one even notices. You more likely felt the system disable a cylinder. So it had shut off fuel and spark to at least one cylinder and whatever occurred to make the system do this was no longer an issue after restart.

Now, why did it disable a cylinder...that I'm not sure...you said you were at full throttle when the issue occurred. A full throttle single misfire may warrant a cylinder disable so the system can protect itself from worse damage. You need more detailed logs or freeze frame data to really tell any more than that.
I see you are in the UK so I assume you have pretty good gas quality but I don't know what year your car is...at 64k km it makes me think it is a 2012-13 so coil packs may not be out of the question. Seems unlike 2 would fail at once and generally when they are failing the issue comes back but it is not impossible.
I still say run some dry gas through and some injector cleaner....I know, I know, injector cleaner doesn't clean the intake valves on a direct injected motor, but it does still help the injector itself. Perhaps some buildup on the injector dislodged at high rpm to cause your issue. Anyway just a theory...trying to help.

[AdrianLee]

I assume this is not your first Audi or VAG product since you have VCDS?
Misfires and in your case a cylinder disable always resets after a restart. Nothing is really "fixed" and the faults are not cleared just the system gives another chance to see if the issue is no longer occurring after restart. Almost all modern cars are this way. And in your case the system no longer had an issue.
The issue you felt really wasn't the single misfire. They happen from time to time and no one even notices. You more likely felt the system disable a cylinder. So it had shut off fuel and spark to at least one cylinder and whatever occurred to make the system do this was no longer an issue after restart.

Now, why did it disable a cylinder...that I'm not sure...you said you were at full throttle when the issue occurred. A full throttle single misfire may warrant a cylinder disable so the system can protect itself from worse damage. You need more detailed logs or freeze frame data to really tell any more than that.
I see you are in the UK so I assume you have pretty good gas quality but I don't know what year your car is...at 64k km it makes me think it is a 2012-13 so coil packs may not be out of the question. Seems unlike 2 would fail at once and generally when they are failing the issue comes back but it is not impossible.
I still say run some dry gas through and some injector cleaner....I know, I know, injector cleaner doesn't clean the intake valves on a direct injected motor, but it does still help the injector itself. Perhaps some buildup on the injector dislodged at high rpm to cause your issue. Anyway just a theory...trying to help.

When I had a similar issue with my A4, I had a stuck injector and it was stuck wide open. I had to rev it to keep it alive too. Was there a strong smell of fuel coming from exhaust?

[AdrianLee]

any luck figuring it out?

[Westyfield2]

I didn't bother, as it only happened once.
Until last week when it happened again. Exactly the same situation: Full throttle, misfire, turn it off and on again, then fine.

Guess I better investigate properly now...

[OOOO SSSS]

My S4 did this 3 times for the 3 years I owned it ( back in 2010). Was a common issue with those cars then without any solutions.


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[Westyfield2]

Had a look at it. Second occurrence of the misfire was the same as the first: Misfire on cylinders 4 & 5 (possibly for just a split second), but then in reaction it shuts down the cylinder.
Ran though the Audi diagnostics.

Have pulled the spark plugs and coils, and swapped them around.

So if it happens again on the same cylinders, then it's injectors or engine stuff. And if it happens again but on different cylinders, then it's spark/coil.

[GLL]

Did you ever figure this out?

Same problem on my 2013 S5. Dealer said they're going to do injectors and plugs.

[Low Flyer]

Did anyone ever figure this out? My 2012 S4 has been at the local dealer for 2 months with the same issue. The combination valve is good, they check my timing, spot on, replaced #4 fuel injector, replace coils and spark plugs...to no avail.

[Low Flyer]

Did anyone ever figure this out? My 2012 S4 has been at the local dealer for 2 months with the same issue. The combination valve is good, they check my timing, spot on, replaced #4 fuel injector, replace coils and spark plugs...to no avail.

Well the dealership did find the issue after doing a running compression test. My catalytic converter was starting to come apart. They replaced it and I have been driving the car for a couple of days, seems like the problem was sorted.

[jrp916]

Well the dealership did find the issue after doing a running compression test. My catalytic converter was starting to come apart. They replaced it and I have been driving the car for a couple of days, seems like the problem was sorted.

Interesting... how many miles do you have? What stage is your car?




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[BOPOH]

i had this happen, especially at WOT - both cats were bad

[rey_reysA7]

Hm wow. I am having this now. But it started the day I changed my spark plugs. It cuts out under hard acceleration, not just WOT but say 3/4 or more. Also when it is heat soaked it shudders the hole time. I put octane booster in it and it helped a lot, still there but not as much. I'm in the middle of a drive from Orlando to Ft Leonard Wood MO. So suck up 3.0"T"

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[i8snitches]

I had this a few weeks back when looking to perform some preventative maintenance when I discussed sparkplug options with APR. APR stated, "stage 2 cars we recommend NGK BKR8EIX gaped to .024"". Jumped on the internet purchased sparkplugs and new coilpacks for good measure. However after two weeks, while on the way to a car event, engine began to stutter/shake. Immediately pulled over to side of road and shutdown engine. I checked for codes with my ODB11 and no fault codes but did see warning on engine.

Towed to my local indy same day -- even-though I was able to drive back home 20miles without issue didn't want to risk any further damage. My local indy shop stated codes were showing misfire on all cylinders... a look at the sparkplugs showed they were burnt. Replaced spark-plugs and so far been driving two weeks with no issue... did a few launches recently and no re-occurrence.

I am still trying to determine why the sparkplugs APR recommended with Stage 2 (DP) would burn up with less than 30-days.

[jrp916]

Hm wow. I am having this now. But it started the day I changed my spark plugs. It cuts out under hard acceleration, not just WOT but say 3/4 or more. Also when it is heat soaked it shudders the hole time. I put octane booster in it and it helped a lot, still there but not as much. I'm in the middle of a drive from Orlando to Ft Leonard Wood MO. So suck up 3.0"T"

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I had almost this exact scenario on my 2.0t a4 after replacing spark plugs, turned out one of the new plugs was defective.


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[rey_reysA7]

I had this a few weeks back when looking to perform some preventative maintenance when I discussed sparkplug options with APR. APR stated, "stage 2 cars we recommend NGK BKR8EIX gaped to .024"". Jumped on the internet purchased sparkplugs and new coilpacks for good measure. However after two weeks, while on the way to a car event, engine began to stutter/shake. Immediately pulled over to side of road and shutdown engine. I checked for codes with my ODB11 and no fault codes but did see warning on engine.

Towed to my local indy same day -- even-though I was able to drive back home 20miles without issue didn't want to risk any further damage. My local indy shop stated codes were showing misfire on all cylinders... a look at the sparkplugs showed they were burnt. Replaced spark-plugs and so far been driving two weeks with no issue... did a few launches recently and no re-occurrence.

I am still trying to determine why the sparkplugs APR recommended with Stage 2 (DP) would burn up with less than 30-days.

Did you replace them again since this?


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