Carbon buildup after 60k. Pic.

[infinkc]

Well, like the other DI engines, the 3.0 also gets carbon buildup. I will be cleaning mine out soon. I took this picture when i had my SC off. Engine was at 60K. Not even close to how bad the V8 engine gets, but its still worse that what it should be.

http://imageshack.us/a/img16/9962/7vr7.jpg

[ihkskim]

what are you going to use to clean?

[Amorphic]

Damn. Why Audi doesnt add a port injector to clean the valves is beyond me. I'm still waiting to see how my A4 will fare with the carbon issues (heard it was supposed to be better for 2013).

[AKPS4]

just curious, why did you pull the supercharger? Did you start to notice any power loss or other issues? Or just decided to check it out?

thanks for sharing! Keep us posted on the results. Any noticeable difference after cleaning, etc...

[drob23]

Well, like the other DI engines, the 3.0 also gets carbon buildup. I will be cleaning mine out soon. I took this picture when i had my SC off. Engine was at 60K. Not even close to how bad the V8 engine gets, but its still worse that what it should be.


That doesn't look as bad as some other pics I've seen, but not great. You gonna go with seafoam? How do you drive your car in general? Short commutes, hard pulls, long commutes?

The PFI won't happen on Audi engines, pretty sure they just deny the existence and chalk it up to DI. Could be due to IP issues, but more likely, I'd guess it would negate some of the EPA ratings they get (penny smart pound foolish). I read that it might have to do with the stratification of the fuel mixture during compression stroke, but that's pretty strong in the conjecture dept. It does appear that VAG engines are worse across the board. Sounds like best way to prevent is to heat it up with some sustained hard driving or clean with seafoam.

[dparm]

For fuck's sake, do NOT Seafoam that thing. Remove the manifold and properly clean it like the RS4 guys do.

I don't think it's that bad. I wouldn't worry about cleaning it for a while.

[Jones2012s4]

just curious, why did you pull the supercharger? Did you start to notice any power loss or other issues? Or just decided to check it out?

thanks for sharing! Keep us posted on the results. Any noticeable difference after cleaning, etc...


I think I know.... [:D] I think it has something to do with alcohol fuel... Muahaha

[psmitty95]

You could try walnut blasting it? That's what us N54 guys do and it comes out spotless. Only way to really get them 100% clean, seafoam does nothing on our motors.

http://customers.precision-sport.com/wp-content/uploads/2013/02/walnut.jpg

[S4 00 2.7]

^^ That's pretty clean.

[SwankPeRFection]

OK, so I have to ask the OP (regardless of whether it's supposed to do anything or not)... Have you ever run any kind of fuel system cleaner through your car since getting it? Again, we're not debating that the fuel/cleaner doesn't get injected above the valves here... everyone knows that it does, I simply want a yes or no answer please.

[SLKStang]

Thats 60k miles? Coming from my RS4, that'd be a dream. You could make it to 100k without any appreciable loss in power. Happy I made the switch.

[NeedQuattro]

Also curious about your daily commute. Highway driving or do you stand a lot in traffic? Short commutes? How often do you go WOT?

[parasound]

Just curious as to why guys are saying don't use Seafoam and it does nothing. I've seem many people use it on big outboard engines with pretty good results (I realize that is a very different animal). But is the thought that it could damage our engines, or it just does nothing?

[cfritos]

You could try walnut blasting it? That's what us N54 guys do and it comes out spotless. Only way to really get them 100% clean, seafoam does nothing on our motors.

http://customers.precision-sport.com/wp-content/uploads/2013/02/walnut.jpg
Great ideal ��

[dparm]

Just curious as to why guys are saying don't use Seafoam and it does nothing. I've seem many people use it on big outboard engines with pretty good results (I realize that is a very different animal). But is the thought that it could damage our engines, or it just does nothing?


Seafoam is the equivalent of an atomic bomb. It's designed as a last-resort type product for neglected motors. A car that has seen routine oil changes with top-tier synthetics (and that gets taken care of in general) shouldn't need that.

I would only use Seafoam in an old beater that was literally on its last legs.

[infinkc]

what are you going to use to clean?
I found a product the RS4 guys use, call BG Direct Injection cleaner, it was made for VW/Audis to do this job with the manifold off. Was pretty hard to find, but i was able to get ahold of some. They do sell it online, but the price they sell it for is really over inflated, i can say i paid a lot less. http://www.ngpracing.com/newstore/bg-gasoline-direct-injection-cleaner-kit.html


just curious, why did you pull the supercharger? Did you start to notice any power loss or other issues? Or just decided to check it out?


I had to replace my thermostat, it went bad on me. Didnt have the cleaner at the time, so i will be pulling it off again.


That doesn't look as bad as some other pics I've seen, but not great. You gonna go with seafoam? How do you drive your car in general? Short commutes, hard pulls, long commutes?

I bought the car CPO, so really dont know the true history of driving on the car, i suspect long commutes and not baby driving as the car had a lot of miles and was modified(intake, exhaust, tune).


I think I know.... [:D] I think it has something to do with alcohol fuel... Muahaha

Main reason was for the thermostat, but yea i was sizing up everything for direct port meth. When i install the meth is when i will clean the ports out. Hopefully the meth will also keep the valves clean in the future.


OK, so I have to ask the OP (regardless of whether it's supposed to do anything or not)... Have you ever run any kind of fuel system cleaner through your car since getting it? Again, we're not debating that the fuel/cleaner doesn't get injected above the valves here... everyone knows that it does, I simply want a yes or no answer please.

Nope never did any additives.

[Boris]

Any b8 s4 owners experiencing power loss as mileage gets higher?

[Doc Masher]

infink, do you have the instructions for the SC removal and install? could you PM me the info?

Thanks

[Boris]

maybe post it here?> I could use that as well.

[lenti]

http://www.powerenhancer.co.uk/

Most BG products you can find here, i bought mine from here when i had my B7 A4, not so expensive and they are great
thinking of trying their products on my B8 S4

[infinkc]

infink, do you have the instructions for the SC removal and install? could you PM me the info?

Thanks


maybe post it here?> I could use that as well.

Sorry don't have a writeup, hardest part was letting the tension off the charger belt with the bumper still on.

I could get the charger off in 30-45 min now that I know how.

I remember just undoing the intake, all the vac lines, belt, coolant lines, and the 6 bolts on top.

I will be taking it off soon again for my meth setup, so I can snap some pics then.


http://www.powerenhancer.co.uk/

Most BG products you can find here, i bought mine from here when i had my B7 A4, not so expensive and they are great
thinking of trying their products on my B8 S4

I used BG direct port cleaner on my q7, it worked well, but I thought it would be easier still. I still had to do a bunch of scrubbing even after a day of soaking. I think I'm going to use gas next time when I do my s4, hopefully the meth will keep it clean also.

[HKIC]

I know guys that let the old VW Diesel heads sit in gas for the night and they come out great. Some were pretty torn up and barely ran before they did this. Wish I had a pic but in one section there was between .3" and .5" on the walls

[westwest888]

Main reason was for the thermostat, but yea i was sizing up everything for direct port meth. When i install the meth is when i will clean the ports out. Hopefully the meth will also keep the valves clean in the future.

Meth will keep it clean. Just don't put it in your mouth.

http://www-tc.pbs.org/wgbh/pages/frontline/meth/art/bodyp2.jpg

[lenti]

Sorry don't have a writeup, hardest part was letting the tension off the charger belt with the bumper still on.

I could get the charger off in 30-45 min now that I know how.

I remember just undoing the intake, all the vac lines, belt, coolant lines, and the 6 bolts on top.

I will be taking it off soon again for my meth setup, so I can snap some pics then.



I used BG direct port cleaner on my q7, it worked well, but I thought it would be easier still. I still had to do a bunch of scrubbing even after a day of soaking. I think I'm going to use gas next time when I do my s4, hopefully the meth will keep it clean also.

would be nice if you can make a writeup when you do the cleaning, could help alot to us my friend.

BTW: How much does a Meth kit cost for our cars?

[shadycrew31]

Hmmm I am at 50K I wanted to pull mine apart a while back but never got around to it.

I am guessing that BG stuff will work really well for the small deposits you found. Do you think you can access the area with out pulling the head?

[Fardrone]

I saw a reply further down ... Has anyone experienced power loss as they've cross the 60k miles mark? And has anybody used any sort of engine cleaner added to the fuel? And what do most of you do for general engine upkeep to keep things tip-top? I'm a new B8 S4 owner ... Bought it used, but I'm lovin it. Thanks!

[wwhan]

infink, do you have the instructions for the SC removal and install? could you PM me the info?

Thanks

This link shows the SC removal; http://www.audizine.com/forum/showthread.php/377783-DIY-S4-Waterpump-and-Thermostat-Install-Supercharger-Removed-%28Pics%29?p=5511910&viewfull=1#post5511910
(http://www.audizine.com/forum/showthread.php/377783-DIY-S4-Waterpump-and-Thermostat-Install-Supercharger-Removed-%28Pics%29?p=5511910&viewfull=1#post5511910)

[westwest888]

I talked with a well known Audi tuning shop about whether carbon buildup would be an issue on the 3.0TFSI. His position was that there will be carbon buildup but it will *not* affect power output. The NA V8 FSI engines are very sensitive to airflow disturbances in the porting. Basically they get robbed of 30 horsepower by 60k miles. Forced induction FSI engines easily overcome the airflow restrictions with either the turbo or the blower. Even if airflow is reduced by 20%, it's all going through at over 2 atmosphere.

Do you need to clean it? That's up to you. It's an engine. There's gunk everywhere. Don't mess with it if it's making normal power.

[moose_head]

Also relevant: http://www.audizine.com/forum/showthread.php/555101-Does-this-come-with-every-new-Audi-A-warranty-extension-for-carbon-buildup/ (thread goes into detail about valves vs secondary air system)

[NWS4Guy]

Also relevant: http://www.audizine.com/forum/showthread.php/555101-Does-this-come-with-every-new-Audi-A-warranty-extension-for-carbon-buildup/ (thread goes into detail about valves vs secondary air system)

Not relevant, as this warranty ONLY addresses the SAI system and buildup in the channels for it. That thread barely touches valve CB issues and the warranty is not about that.

[apexit1]

not so much the engine being less sensitive to build up but just that they produce less crap to build up

[drob23]

I thought the 2.0T had carbon problems, thus refuting this "FI engines don't suffer buildup problems" theory. My understanding is the 3.0T runs 10 deg (not sure if C or F) warmer than the 3.2 which helps burn off the soot.

Sent from my SCH-I535 using Tapatalk

[B8 S FOR]

Meh .... not that bad! I've seen much worse...good to see our engine holding up better than the 4.2 V8!

[priceprince]

I'll ask the same question a couple others have asked, but hasn't been answered yet: is anyone seeing a noticeable loss in power as they approach 50-60k miles?
I'm guessing not, as there would be people complaining about it like crazy in other threads. Seems that the 3.0T doesn't have the major carbon buildup issue like the RS4 and other DI engines.

[NWS4Guy]

I'll ask the same question a couple others have asked, but hasn't been answered yet: is anyone seeing a noticeable loss in power as they approach 50-60k miles?
I'm guessing not, as there would be people complaining about it like crazy in other threads. Seems that the 3.0T doesn't have the major carbon buildup issue like the RS4 and other DI engines.

You would need to dyno the car a long time apart and hope to have temps as close as possible, hope the same dyno is still calibrated the same way and lots of other variables line up to tell. Since you are driving the car daily, you will not notice the changes, as they are slow and gradual just like aging. There is a reason you don't see any changes day to day, but someone who has not seen you in years says you look different.

[priceprince]

^good analogy, I like it. :)

[drob23]

I'll ask the same question a couple others have asked, but hasn't been answered yet: is anyone seeing a noticeable loss in power as they approach 50-60k miles?
I'm guessing not, as there would be people complaining about it like crazy in other threads. Seems that the 3.0T doesn't have the major carbon buildup issue like the RS4 and other DI engines.

I think in this case, no news is good news.

[B8 S FOR]

I am another victom of carbon buildup in my B8 S4. Background: Check engine light came on yesterday [headbang], 42,500 miles, 2011 S4 driven very hard all the time [confused]. Very little stop and go traffic mostly highway. Took to my dealer today they ran a VAG and sure enough Carbon Buildup! Was told they have to order the gasket etc... and will call me to come back. I am now covered to 100K if this happens again. No noticable loss of power at all???[wrench] Is there a Carbon Buildup thread for the B8/B8.5 S4? Couldn't find one?

[drob23]

I am another victom of carbon buildup in my B8 S4. Background: Check engine light came on yesterday [headbang], 42,500 miles, 2011 S4 driven very hard all the time [confused]. Very little stop and go traffic mostly highway. Took to my dealer today they ran a VAG and sure enough Carbon Buildup! Was told they have to order the gasket etc... and will call me to come back. I am now covered to 100K if this happens again. No noticable loss of power at all???[wrench] Is there a Carbon Buildup thread for the B8/B8.5 S4? Couldn't find one?

They said buildup on your intake valves or the secondary air intake system? You'd think if this was the intake valves, you would have had power loss. You mind posting the code if you have it? Assuming this is covered by AoG?

[audistealth]

I am another victom of carbon buildup in my B8 S4. Background: Check engine light came on yesterday [headbang], 42,500 miles, 2011 S4 driven very hard all the time [confused]. Very little stop and go traffic mostly highway. Took to my dealer today they ran a VAG and sure enough Carbon Buildup! Was told they have to order the gasket etc... and will call me to come back. I am now covered to 100K if this happens again. No noticable loss of power at all???[wrench] Is there a Carbon Buildup thread for the B8/B8.5 S4? Couldn't find one?

Do you have any pics? What would the cost have been out of warranty?

[B8 S FOR]

No pics but I can ask my guys to take some when they start work on it. Out of pocket I was quoted $900 - $1,100!! The parts cost nothing it's the labor involved! They said it will take a day or day and a half to complete the work! They have to take off the entire front clip, all the piping etc to get to it? Thats what I was told.

[audistealth]

Man, that's a lot for something Audi should have designed better in the first place.

[infinkc]

No pics but I can ask my guys to take some when they start work on it. Out of pocket I was quoted $900 - $1,100!! The parts cost nothing it's the labor involved! They said it will take a day or day and a half to complete the work! They have to take off the entire front clip, all the piping etc to get to it? Thats what I was told.

They probably remove the front to get the belt off the charger, but if you have the right tools there is no need to remove the front end to get the belt off, ive taken the belt off many times.


Man, that's a lot for something Audi should have designed better in the first place.

Its not audis fault, its a issue with direct port injection engines. since there is no fuel flowing through the intake anymore, crap builds up instead of being cleaned.

[audistealth]

I understand the DI part, but isn't that why some setups have a port injector too? To wash away before build up?

[westwest888]

This whole thread has no basis for concern until someone can prove that after a carbon cleanup, their engine produced > 10% more horsepower. The truth is it's not a problem in forced induction engines. If you've got an old Audi 4.2, carbon in the ports can rob some power from you. If you've got a blower or a turbo ramming air into the cylinder at multiples of normal atmospheric pressure, the carbon doesn't restrict airflow meaningfully.

[b8audis4]

Although s4's may have a carbon issue my 335i was a lot worse.

[B8 S FOR]

Fact is I drive the living hell out of this car and it still happened! It will and can happen to any of you. Just a heads up! Thank god for the TSB!!!! $900-$1,100 out of pocket is RAPE!

[IanCH]

This whole thread has no basis for concern until someone can prove that after a carbon cleanup, their engine produced > 10% more horsepower. The truth is it's not a problem in forced induction engines. If you've got an old Audi 4.2, carbon in the ports can rob some power from you. If you've got a blower or a turbo ramming air into the cylinder at multiples of normal atmospheric pressure, the carbon doesn't restrict airflow meaningfully.

The difference may not be noticeable but unless there is a significant change in Reynolds number of the air flowing in the ports between FI and NA engines then the lost airflow volume is proportionally the same.

If I got some specifics together about the inlet pressure and volume drawn combined with WOT at top RPMs then I could make a comparison (as could any other engineer on here). Next time I'm bored at work I will put some rough stuff together. Does anyone know the dimensions of the port cross sectionally? (width and height)

The actual amount of carbon buildup seen in NA engines appears to be higher than any pic I have seen from a 3.0t that "had carbon issues"

[westwest888]

The difference may not be noticeable but unless there is a significant change in Reynolds number of the air flowing in the ports between FI and NA engines then the lost airflow volume is proportionally the same.

If I got some specifics together about the inlet pressure and volume drawn combined with WOT at top RPMs then I could make a comparison (as could any other engineer on here). Next time I'm bored at work I will put some rough stuff together. Does anyone know the dimensions of the port cross sectionally? (width and height)

The actual amount of carbon buildup seen in NA engines appears to be higher than any pic I have seen from a 3.0t that "had carbon issues"

The intermediate metrics are interesting but we can just work backwards from the result we want to get. First someone needs to think their car is low on power and has to dyno it. If you're posting 280 at the wheel you are fine. If you're posting under 250 maybe you have an issue. Then get the carbon cleaning service. Then dyno again and show that you restored the power to 280+. Only at that point does the community need to worry about carbon as an extended maintenance burden.

It's not a problem on 2.0TFSI engines in terms of power loss. Only the NA models.

[cspcrx]

WESTWEST, you crack me up! 10% people don't even get that after adding intakes and exhausts to these cars in stock form. I love how you just come up with this stuff.

[B8 S FOR]

Okay so I dropped her off this morning for the Carbon Buildup TSB and they told me it will take a few days to complete? As ususal I was provided a Base VW Passat with FWD and it's snowing like a mother FU#@!$!. Honesty, If I was to drop say 80+K on an Audi and they gave me this POS I would be really pissed off! Anybody agree here? Similar stories? My dealer is a VW / Audi combined operation and sell high end Audis like R8, S8, S7 etc.......

[IanCH]

The carbon clean only takes about 4 hours, but its 4 continuous hours so they have to carve time out of a tech's schedule. Sounds about the estimate that most dealers would give you.

[B8 S FOR]

The carbon clean only takes about 4 hours, but its 4 continuous hours so they have to carve time out of a tech's schedule. Sounds about the estimate that most dealers would give you.

Yeah the SA was telling me that they only have like "1" Tech that does this. It seems to me that Audi every QTR is selling many more cars but their service operations aren't getting any bigger or is me ? ? ?

[nwps4]

honestly I hate to break It to you #b8sfor but they are doing the secondary air cleaning not cleaning your intake valves it sounds like because you said the front clip has to be taken off. If they were cleaning your intake valves you would have to have faults stored for random cyl miss fires or hard miss fires on cyl and have to swap the coils and plugs to verify that the intake valves are gummed up and if you were having this problem you would honestly feel the power loss/ slight miss fire under light loads when the SC is not building pressure. If you had no power losses and the check engine light came on then the secondary are system is clogging up with carbon, and on the 3.0 engines it is more of a pain than a 3.2 and will take between 4-8 hours depending on who is doing it. sorry for the service writer not knowing anything about cars but what ever they extended the warranty on it to 10years/120k I believe.

[B8 S FOR]

honestly I hate to break It to you #b8sfor but they are doing the secondary air cleaning not cleaning your intake valves it sounds like because you said the front clip has to be taken off. If they were cleaning your intake valves you would have to have faults stored for random cyl miss fires or hard miss fires on cyl and have to swap the coils and plugs to verify that the intake valves are gummed up and if you were having this problem you would honestly feel the power loss/ slight miss fire under light loads when the SC is not building pressure. If you had no power losses and the check engine light came on then the secondary are system is clogging up with carbon, and on the 3.0 engines it is more of a pain than a 3.2 and will take between 4-8 hours depending on who is doing it. sorry for the service writer not knowing anything about cars but what ever they extended the warranty on it to 10years/120k I believe.


You probably are correct. Honestly, I never really get a "warm fuzzie" when I drop my car off. I sometimes feel I know a little more then they do. As if I fully "trust" them. It just seems that Audi can't keep up with service demand. This may be Audi's demise.

[AKPS4]

What type of gas have you used and what oil? No one flame or respond if you have nothing useful to say. I am tracking for my own purposes if not anyone else's. Thanks.

[hodrosS42001]

Need to rev it out more to clean those valves! Buddy had a S6 v10 (known for carbon buildup) bought it with 30k drove the piss out of it I mean it saw redline multiple times each trip. At 70k took a look and had no buildup at all.. then he sold the car.. DI just don't like light load.. you need to revout every now and then.

[NWS4Guy]

Need to rev it out more to clean those valves! Buddy had a S6 v10 (known for carbon buildup) bought it with 30k drove the piss out of it I mean it saw redline multiple times each trip. At 70k took a look and had no buildup at all.. then he sold the car.. DI just don't like light load.. you need to revout every now and then.

Once more with feeling.


THIS THREAD HAS NOTHING TO DO WITH CARBON BUILDUP ON THE VALVES.

Zero

nada

This is carbon building up in the SECONDARY AIR CHANNELS and clogging them. This affects EMISSIONS ONLY. This will trigger a CEL during cold start, when the secondary air pumps try to pull unburned fuel through the clogged channels, which will deposit these on the cats directly. This causes the cats to react and heat up sooner, thereby lowering the time it takes for the cats to become hot enough to begin catalyzing emissions, and lowering emissions.

[B8 S FOR]

Once more with feeling.


THIS THREAD HAS NOTHING TO DO WITH CARBON BUILDUP ON THE VALVES.

Zero

nada

This is carbon building up in the SECONDARY AIR CHANNELS and clogging them. This affects EMISSIONS ONLY. This will trigger a CEL during cold start, when the secondary air pumps try to pull unburned fuel through the clogged channels, which will deposit these on the cats directly. This causes the cats to react and heat up sooner, thereby lowering the time it takes for the cats to become hot enough to begin catalyzing emissions, and lowering emissions.

Correct. Got the car back after 3 days of being in the shop. They did remove the Front Bumper, pulley, intake and some other stuff to access and clean the ports. When I picked the car up after the ports were cleaned, I did notice an increase in HP or throttle response. The car seems to go through the gears quicker with ease as if it can breathe better. Just my observation. Before I took the car in it was sluggish off the line and from a 30-60 roll. I always use 93 or higher Octane always! Only pump gas. He quoted me $1,200 for the job but was covered under the TSB 100%! Now covered to 120K.

[NWS4Guy]

Correct. Got the car back after 3 days of being in the shop. They did remove the Front Bumper, pulley, intake and some other stuff to access and clean the ports. When I picked the car up after the ports were cleaned, I did notice an increase in HP or throttle response. The car seems to go through the gears quicker with ease as if it can breathe better. Just my observation. Before I took the car in it was sluggish off the line and from a 30-60 roll. I always use 93 or higher Octane always! Only pump gas. He quoted me $1,200 for the job but was covered under the TSB 100%! Now covered to 120K.

That is purely speculation, cleaning out the secondary air ports has no impact whatsoever on performance. They are open for about 1 minute on cold start, then a valve closes the air channels off. It has zero to do with how the car performs at all, and is only a emissions mandate by the government.

[B8 S FOR]

That is purely speculation, cleaning out the secondary air ports has no impact whatsoever on performance. They are open for about 1 minute on cold start, then a valve closes the air channels off. It has zero to do with how the car performs at all, and is only a emissions mandate by the government.

In all honesty...the car feels more responsive. Now...it may be due to the fact that they gave me a Passat 4 banger to drive for three days! So what is the major cause of this clogging? Any preventative measures?

[NWS4Guy]

In all honesty...the car feels more responsive. Now...it may be due to the fact that they gave me a Passat 4 banger to drive for three days! So what is the major cause of this clogging? Any preventative measures?

These are tiny little holes INSIDE the top of the cylinder, which lead through the heads and block, back to the catalytic converters. In fact, they overall likely make the car slower, because without the secondary pumps, lines that carry the unburned fuel from cold start, and the associated valves, the car would be lighter and thereby faster. Driving it hard is the only thing that can bake off carbon, though a less rich fuel mixture, and supposedly Top Tier fuels will also burn cleaner, leaving less junk behind to cause buildup. The CB that is known to rob power builds up on the valves, which are OUTSIDE the cylinder, but push into the cylinder top to allow fuel/air in, and exhaust out.


Here is a pic from a BMW, which is known to have the issues. You can see the very small holes pointed out and the grey looking carbon plugging them:

http://www.turnermotorsport.com/image/topics/S62_carbon_front_90deg_turn.jpg

Another here shows the port below the timing belt, where it comes through the engine block:

http://www.turnermotorsport.com/image/topics/S62_carbon_front_port_blocked.jpg

Conversely, here is a bad set of intake valves. These open into the cylinder and allow the air into the cylinder. Our cars are direct injection, where the air comes in, and the fuel is sprayed into the cylinder directly (hence the name), while in non-DI cars, the fuel is sprayed on the valve itself as it opens, washing it every time it opens, preventing carbon from building up. With this much carbon, the air is not flowing easily or in the pattern designed to make the best mixture with the fuel being sprayed into the cylinder, and robbing you of power. The source of this carbon is similar, it's an emissions system that recirculates the crankcase air, which will have globs of oil in it atomized in small particles. These are carried into the cylinder to be burned with the fuel, so they pollute less.

http://www.etuners.gr/userfiles/mammos04092011800_2_0TFSI_intake_dirty.jpg

[westwest888]

I was actually expecting a rainbow of skittles to be inside of the valve covers. I am shocked that gasoline and oil go in, and carbon comes out. I really hope the engineers at Audi know that carbon can get inside of the engine. Do you think they thought about this?

On a related note there is dust and pollen inside of my Dyson. I'm going to go start a thread over on Consumer Reports. I had to clean it after 6 uses. I know, it's insane.

[B8 S FOR]

These are tiny little holes INSIDE the top of the cylinder, which lead through the heads and block, back to the catalytic converters. In fact, they overall likely make the car slower, because without the secondary pumps, lines that carry the unburned fuel from cold start, and the associated valves, the car would be lighter and thereby faster. Driving it hard is the only thing that can bake off carbon, though a less rich fuel mixture, and supposedly Top Tier fuels will also burn cleaner, leaving less junk behind to cause buildup. The CB that is known to rob power builds up on the valves, which are OUTSIDE the cylinder, but push into the cylinder top to allow fuel/air in, and exhaust out.


Here is a pic from a BMW, which is known to have the issues. You can see the very small holes pointed out and the grey looking carbon plugging them:

http://www.turnermotorsport.com/image/topics/S62_carbon_front_90deg_turn.jpg

Another here shows the port below the timing belt, where it comes through the engine block:

http://www.turnermotorsport.com/image/topics/S62_carbon_front_port_blocked.jpg

Conversely, here is a bad set of intake valves. These open into the cylinder and allow the air into the cylinder. Our cars are direct injection, where the air comes in, and the fuel is sprayed into the cylinder directly (hence the name), while in non-DI cars, the fuel is sprayed on the valve itself as it opens, washing it every time it opens, preventing carbon from building up. With this much carbon, the air is not flowing easily or in the pattern designed to make the best mixture with the fuel being sprayed into the cylinder, and robbing you of power. The source of this carbon is similar, it's an emissions system that recirculates the crankcase air, which will have globs of oil in it atomized in small particles. These are carried into the cylinder to be burned with the fuel, so they pollute less.

http://www.etuners.gr/userfiles/mammos04092011800_2_0TFSI_intake_dirty.jpg

Thanks for the illustration! So basically it's by design and there is no way to prevent this?

[NWS4Guy]

Thanks for the illustration! So basically it's by design and there is no way to prevent this?

It's always been an issue for direct injection engines. Each year the companies do things to advance the design to address it while staying in compliance with emissions, though honestly most just try to make it slow down enough so the car is out of warranty when it causes an issue so it's the owner's problem to address. There is a complex labyrinth system which is just like it sounds, where the crankcase ventilation traverses through meant to trap the oil and particles to drip them back into the system so the oil filter can collect them, but some gets through. The valves have to stay relatively cool for their work, so the carbon cakes on them instead of being baked off by heat. Some companies (like Lexus) have introduced a secondary injector where they used to be which will occasionally spray the valve to clean them in addition to the DI method. Forced induction engines (supercharged and turbo) typically are a little better with the buildup than NA (naturally aspirated) engines. The Lambo derived V10 in the R8 has the issue very bad for example.

[B8 S FOR]

It's always been an issue for direct injection engines. Each year the companies do things to advance the design to address it while staying in compliance with emissions, though honestly most just try to make it slow down enough so the car is out of warranty when it causes an issue so it's the owner's problem to address. There is a complex labyrinth system which is just like it sounds, where the crankcase ventilation traverses through meant to trap the oil and particles to drip them back into the system so the oil filter can collect them, but some gets through. The valves have to stay relatively cool for their work, so the carbon cakes on them instead of being baked off by heat. Some companies (like Lexus) have introduced a secondary injector where they used to be which will occasionally spray the valve to clean them in addition to the DI method. Forced induction engines (supercharged and turbo) typically are a little better with the buildup than NA (naturally aspirated) engines. The Lambo derived V10 in the R8 has the issue very bad for example.

Thanks! I guess we are all in for the same here at some point!

[Vogz]

Once more with feeling.


THIS THREAD HAS NOTHING TO DO WITH CARBON BUILDUP ON THE VALVES.

Zero

nada

This is carbon building up in the SECONDARY AIR CHANNELS and clogging them. This affects EMISSIONS ONLY. This will trigger a CEL during cold start, when the secondary air pumps try to pull unburned fuel through the clogged channels, which will deposit these on the cats directly. This causes the cats to react and heat up sooner, thereby lowering the time it takes for the cats to become hot enough to begin catalyzing emissions, and lowering emissions.

While I agree that the direction the thread has taken for the most part is the sec air channels clogging up, the OP posted a pic of his intake valves. This thread STARTED as a thread about carbon buildup on intake valves.

[NWS4Guy]

While I agree that the direction the thread has taken for the most part is the sec air channels clogging up, the OP posted a pic of his intake valves. This thread STARTED as a thread about carbon buildup on intake valves.
Agreed, but with the attention span of some people on Azine, they will head immediately to their dealer to get a free valve cleaning citing a TSB for it.

[vliou]

It's always been an issue for direct injection engines. Each year the companies do things to advance the design to address it while staying in compliance with emissions, though honestly most just try to make it slow down enough so the car is out of warranty when it causes an issue so it's the owner's problem to address. There is a complex labyrinth system which is just like it sounds, where the crankcase ventilation traverses through meant to trap the oil and particles to drip them back into the system so the oil filter can collect them, but some gets through. The valves have to stay relatively cool for their work, so the carbon cakes on them instead of being baked off by heat. Some companies (like Lexus) have introduced a secondary injector where they used to be which will occasionally spray the valve to clean them in addition to the DI method. Forced induction engines (supercharged and turbo) typically are a little better with the buildup than NA (naturally aspirated) engines. The Lambo derived V10 in the R8 has the issue very bad for example.

I've been heads down buried in technical documents comparing the EA837 (3.0 TFSI) and the EA839 (new 6 cylinder engine coming to the 2019 Audi A6/7/8, Porsche Macan/Panamera, cayenne etc), and it appears that the crankcase breather system does exactly as you mentioned, and hasn't improved much. The 839 engine now utilizes cast in place cooling channels that drop the cylinder wall temps by 20'C. That said the oil separation system on these two engines, and on the M276 engines at Mercedes (which also do not suffer systemic carbon build up issues) seems to indicate to me that DI engines have improved with respect to carbon buildup.

While the Lexus D4S system that you are referring to operates in both FI and DI modes depending on engine load, the reality is that most other manufacturers have not done this, or some (including Ford/GM) have abandoned DI engines altogether (in their 3.7L engine available in the US).

All this to say, I have followed this topic extensively since 2007 when I bought the B7 A4 (2.0 FSI) and after about 7 years of happily owning a port fuel injected Mercedes (due to the disaster of the B7 A4), I'm now looking at DI engines again. The M276 engine oil separator is well documented and operates very similarly to the Audi solution. (although probably better) - I have a technical document of all three engines and how they separate oil from air.

So to summarize, is there really a systemic issue with carbon buildup on Audi engines (V6 and V8?). I looked at the technical training document from Audi in regards to the 4.0 TFSI hot V engine and the oil/air separator is also very complex, and similar to the engines mentioned here with respect to a dual stage system between a coarse and fine oil separator.