Carbon Build Up - 2008 Audi A4 3.2L

[Tanner]

So basically if I drive like a maniac I'll never have to worry about this problem? My does car hesitate to start sometimes, but once it gets going it seems to be fine. Also, I have not had the CEL come on and the I'm just about to reach 28k miles.

I wouldn't say "drive like a maniac" but rather keep the revs high and give it WOT from time to time.

[JGreen76]

I have no CEL's, nor do I notice any real problems. When I start the car in the morning, my idle seems to have a pulse to it... It's not a rough idle, but more of a pulse sound. Is that normal, or do you think I should see if CB is creating this? My car has 46K on it.

[rmh]

One more data point. My car: 2008 A4 B7 3.2 6MT


I've got the Ross-Tech VCDS scanning tool and have been scanning my car every 2000-4000 miles since I got it and I've captured logs of all my scan results and summarized them into a spreadsheet with every maintenance item performed on the car. I work a lot from home, so my car sits for extended periods of time, between relatively long drives. I'm a spirited driver, so I change my oil every 5000 miles. I had AudiCare thrown in when I bought the vehicle, so all work has been performed at the dealer to date.


For the past 8000 miles, I've been getting P0303, P0304, P0305, P0306 and P0300 codes (VAG codes 000771, 000772, 000773, 000774 and 000768, respectively).


My CEL has come on twice (it doesn't come on when the codes start showing up, only after some period of time) and is currently at the dealership. TSB 2019948/2 was performed almost exactly 4000 miles ago. Service advisor tells me that all DI engines by all manufacturers are starting to see this problem since the fuel isn't flowing past the valves and cleaning the valves. Service advisor tells me BMW, VW, Audi, Honda, Toyota, and GM all advise their vehicle owners to use Top Tier gas (see http://www.toptiergas.com/index.html, http://www.toptiergas.com/retailers.html, and http://www.toptiergas.com/deposit_control.html).


I spent quite a bit of time researching the availability of Top Tier gas in my area, and there are currently 23 locations where I can even find Top Tier gas within 50 miles of where I live, and I think 1 within 10 miles.


Typical VAG-COM scan snippet (note only 2 throw a MIL):

000772 - Cylinder 4: Misfire Detected 
               P0304 - 007 - Short to Ground - Intermittent - MIL ON
             Freeze Frame:
                    Fault Status: 10100010
                    Fault Priority: 6
                    Fault Frequency: 4
                    Reset counter: 40
                    Mileage: 37794 km
                    Time Indication: 0

             Freeze Frame:
                    RPM: 1472 /min
                    Mass Air / Rev.: 207.1 mg/str
                    Temperature: 16.5°C
                        Part Throttle
                    Time: 51.2 s
                    Speed: 11.0 km/h

000774 - Cylinder 6: Misfire Detected 
               P0306 - 007 - Short to Ground - Intermittent - MIL ON
             Freeze Frame:
                    Fault Status: 10100010
                    Fault Priority: 6
                    Fault Frequency: 5
                    Reset counter: 40
                    Mileage: 37794 km
                    Time Indication: 0

             Freeze Frame:
                    RPM: 1472 /min
                    Mass Air / Rev.: 207.1 mg/str
                    Temperature: 16.5°C
                        Part Throttle
                    Time: 51.2 s
                    Speed: 11.0 km/h

000773 - Cylinder 5: Misfire Detected 
               P0305 - 007 - Short to Ground - Intermittent
             Freeze Frame:
                    Fault Status: 00000010
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 5
                    Mileage: 37794 km
                    Time Indication: 0

             Freeze Frame:
                    RPM: 928 /min
                    Mass Air / Rev.: 179.8 mg/str
                    Temperature: 19.5°C
                        Idle
                    Time: 51.2 s
                    Speed: 4.0 km/h

000768 - Random/Multiple Cylinder Misfire Detected 
               P0300 - 006 - Short to Plus - Intermittent
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 6
                    Fault Frequency: 5
                    Reset counter: 40
                    Mileage: 37794 km
                    Time Indication: 0

             Freeze Frame:
                    RPM: 1472 /min
                    Mass Air / Rev.: 207.1 mg/str
                    Temperature: 16.5°C
                        Part Throttle
                    Time: 51.2 s
                    Speed: 11.0 km/h

000771 - Cylinder 3: Misfire Detected 
               P0303 - 007 - Short to Ground - Intermittent
             Freeze Frame:
                    Fault Status: 00000010
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 23
                    Mileage: 38416 km
                    Time Indication: 0

             Freeze Frame:
                    RPM: 896 /min
                    Mass Air / Rev.: 163.5 mg/str
                    Temperature: 21.0°C
                        Idle
                    Time: 51.2 s
                    Speed: 0.0 km/h

[Tanner]

HAve you tried using a fuel line cleaner? The high pressure injectors are known to get a bit clogged up. I had a few misfires but one noticeable misfire that generated a fault code but no CEL. Went through two tanks with Motul fuel line cleaner, ran it hard (italian style tune-up) and the back bumper was covered in soot. Since then, no issues and use one bottle of the stuff every six months now. It won't prevent buildup on the intake valves of course.

If the misfires continues after using two tansk with the cleaner, I'd then be pressuring Audi to look at the intake valves. Document everything that you have done along the way.

[rmh]

The last time my car was in at the dealer with the initial carbon buildup misfire CEL, I ended up with a bottle of "Fuel Additive for Petrol Engines", in my car. I'm sure it's what the dealer used on my car. Why I had a full bottle on the floor of the passenger's seat is unknown.

On this (full) 150ml bottle, it says: Made in Germany, Distributed by Volkswagen AG. It has the VW, SEAT, SKODA and Audi logos on it. It is part # G 001 700 03. Instructions say to mix 10 ml per 10 litre petrol to prevent corrosion, carburetor icing and keeping intake ports clean. See either http://www.worldimpex.com/parts/oem-cleaner_71921.html or http://www.ecstuning.com/Search_VW/G00170003/ to buy some.

I think I'll pick up a case of this stuff and run it through periodically.

Update:
Got my car back from the dealer today.

Service advisor (SA) gave me another bottle of the additive (part #G00170003), and tells me to put it in a full tank of gas in about 1500 miles.

SA tells me that this stuff is the Audi recommended way to keep valves and injectors clean. SA also told me that their service procedure involves much less than a full tank of gas and a full bottle of this additive, then they drive the car for 90 miles and retest.

Hmmm, let's see... The bottle says 10ml to 10l (1:1000 additive:fuel ratio) which equals 1ml per 0.264 gal, so for the 16.6gal tank in my A4, I should use 62.84ml of the stuff. So, a full 150ml bottle in my tank yields a 1:419 additive:fuel ratio.

I asked SA about the use of Motul Fuel System Cleaner - he didn't know the formulary differences between that and the Audi product.

I just called ECSTuning - this part # is currently not available to the public - it's on something like a referral hold from Audi, the great guy I spoke to at ECSTuning said that when parts go on this status it means that either there's a recall coming or something but it's to ensure that the dealers can get the quantities they need. Bummer...

Update:
The good news is that my SA told me that I can buy this product at the parts counter and get my ACNA discount on it. I'll update later with the details on (hopefully, case) pricing.

[BEM3]

I wanted to share another carbon build up issue and have already posted this in the Audi FSI Engine Carbon Build-up Megathread in the Transmission & Drivetrain Forum.

Here’s another data point. This is my first post and unfortunately it doesn’t have anything good to report…

Vehicle Make/Model: 2008 Audi A4 3.2L
Location: Seattle, Washington
Mileage/Date: 11,990 miles / 30 November 2009
Oil used: Unknown. Dealer Supplied
Oil Change Interval: Average every 2850 miles*
Fuel Used: Chevron Supreme Techron (91/92 octane) or Shell V-Power (91/92 octane)
How short/long are your trips on average: 6 to 30 miles

Reported rough idle when cold to the dealer. CEL was on. Did not notice any loss of power.

Dealer invoice states:

“Verified Customer Concern. Hooked up scan tool, found five random engine faults. P0300, P0301, P0302, P0303, and P0304 (random cylinder misfire, cylinder misfire 1-4). Followed TSB 2019948/3, added fuel additive and road tested vehicle for 60 miles sustaining high engine RPM. Allowed vehicle to sit for several hours to repeat cold start up. Hooked up scan tool and cold started vehicle, MVB 14 registered 8 faults (4 in cylinder 1, 2 in cylinder 2, and 2 in cylinder 3). Will open TAC ticket. **- (Tech 2751) opened TAC ticket. They said to check camshaft adjustment. Performed check through MVBS 90-96 and they are fine, there are no sticking adjusters. Removed intake manifold and found carbon build up on back of valves. TAC said to perform cleaning as stated in the TSB. Cleaned valves, removed spark plugs, blew out carbon chunks. Reassembled and test drove. Let sit outside overnight and started cold. There was no misfire on any cylinder. Performed oil service per TSB. Closed TAC ticket. Done.”

Note:
Vehicle purchased new with 49 miles / 27 September 2008
Engine (short block) replaced for cylinder wall scoring 6521 miles / 14 April 2009
*Oil change interval shorted by engine replacement
Drove the car from Seattle to San Francisco and back. It currently has over 15,000 miles on it and its starting to run rough when cold again. Thank goodness for warranty!

UPDATE:

Carbon build up again despite driving the car longer and harder…

Vehicle Make/Model: 2008 Audi A4 3.2L
Location: Seattle, Washington
Mileage/Date: 18,082 miles / 01 April 2010
Oil used: Unknown. Dealer Supplied
Oil Change Interval: Average every 4520 miles*
Fuel Used: Chevron Supreme Techron (91/92 octane) or Shell V-Power (91/92 octane)
How short/long are your trips on average: 6 to 30 miles

*Oil change interval shorted by engine replacement and valve cleaning

Issue: “Client states CEL is on and vehicle has a rough idle when started cold”

Dealer invoice states: “Verified Check Engine Light was on, performed guided fault finding, found fault P0301 Cylinder 1 misfire detected, P0303 Cylinder 3 misfire detected, both were at cold start, checked for TSB’s, found TSB2020645/4 for ECM update, updated software, suggest leaving car overnight to cold start and verify repair retested AM ok.


Less than a week later…


Vehicle Make/Model: 2008 Audi A4 3.2L
Location: Seattle, Washington
Mileage/Date: 18,255 miles / 09 April 2010
Oil used: Unknown. Dealer Supplied
Oil Change Interval: Average every 4520 miles*
Fuel Used: Chevron Supreme Techron (91/92 octane) or Shell V-Power (91/92 octane)
How short/long are your trips on average: 6 to 30 miles

*Oil change interval shorted by engine replacement and valve cleaning

Issue: “Client states the Check Engine Light is on. Please verify and advise (rough when cold)

Dealer invoice states: “XXXXX Could not verify concern.. No Check Engine Light on. Ran GFF and found faults P0301 and P0303. Same faults as before engine replacement. Removed all six coils and spark plugs. Checked cylinder walls for wear. Cylinder 3 shows reseding cross hatch. Checked history and found short block has been replaced, valve cleaning has been performed 6000 miles ago. ECM update has been performed. Camshaft Tensioner has been replaced for misfires on one bank. After gathering all information on this vehicle made a TACS Ticket. Access code XXXXXX. Case number XX-XXXXXX. Instructed to perform another valve cleaning and application of G17 fuel additive to fuel system following TSB number 2019948/3. Had 2 hrs of diag and preperation prior to repair. Added fuel additive to fuel tank, also filled gas tank with 10 gallons of fuel and drove vehicle for 60 miles. Slight misfires still felt. Removed intake manifold and air distribution housing. Cleaned off valves and swapped Injectors 1 with 4 and 3 with 6 for further diag in future if needed. Replaced all seals on swapped injectors. Removed all spark plugs and blew out any debris. Reinstalled all removed components. Performed an oil change under warranty as per TSB. Cold started vehicle and verified no cold start misfires. Every once and a while the vehicle needs to be driven harder than normal to clean off any carbon buildup on back of valves. Placing fuel additive in truck of vehicle and recommend adding in 3000 miles. G17 additive should be added on full tank.”

I am not confident that this is a permanent fix, but at least the dealer is doing what they can.

[Red Baron777]

I wanted to let you know of my experience with my 08 A4 Cab s-line 3.2 concerning the CEL issue. I bought this car a year ago with very low miles(8K) on it. I have the remainder of the factory warr. and the CPO. I started experiencing CEL issues at about 16K. I brought it to dealer at 20K and they did the usual additive and test drive and returned it to me. The car now has 25K and is in for its routine service. The CEL has being going on and off for the last 5K miles. The dealer is now manually cleaning all the valves and returning the car to me, probably tomorrow. I have used only Shell premium since I had the car and will continue to do so. We will see what happens when I get the car back. As a side note, I have had many Audi's since the early 2000's as did my wife(she's had 2 S-4's and an A4(when the S4 was not available in 2003, I believe). I had a major problem with my 2002 A4 where it was burning thru cat converters. After replacing 3 CC and not knowing what else to do, they took the car back and gave me a new 2003(the 2002 was not in production anymore). Prior to that my daughter's VW Passat just stopped while driving for no apparent reason. After jumping thru some hoops, they took that back also and refunded to me all my payments less wear and tear on the car. That's when I bought her the 2001 A4 1.8T which is still on the road with 93K miles. Suffice it to say, I am a believer in the product and feel I have been treated fairly by them, so far. I will have to wait and see how this current problem plays out.

[vwjetta1.8t]

I've just picked up an 07 3.2 a4 avant 3 weeks ago and my cel started flashing the second day I had the car. My ESP light also came on at the same time. I was on the highway and the car was shuddering and there was reduced power on acceleration. Brought it to the dealership and they changed the fuel injector in cylinder 2. Car ran ok until today. 1500k later and the same problem. I was backing into my driveway when I felt the car start shuddering (misfire?). The esp light came on then the CEL started flashing. Are these the same symptoms that you guys with carbon issues experiencing? Hooked the car up to an OBD2 and getting codes p0202 and p0302.

[Red Baron777]

Not me. The CEL would come on at cold start-up and although it stayed on, the car ran fine after about 20 seconds. By the way of my first post, the dealer pulled off the heads and the intake manifold fold, manually cleaned all the valves andfound a faulty injector in one of the cylinders. They replaced it and I have had the car back for 1,000 miles and it seems fine, at least for now.

[min417]

Hey all-
Just came back running some freeways after reading the threads. =)

I also have had the carbon build up issue on my 3.2 at 12K miles, with the check engine light on. Engine kept on misfiring and the dealer removed intake and inspected for carbon build up and they actually had scraped the build up off. Then again by 15K miles the light came on again and had to take it to the dealer again for same issue, this time cleaning up all intake valves and cylinders. I was given the VW fuel injector cleaner to be put in with next gas fill up, where they recommended to burn up.

[rmh]

Another update - 3rd CEL within 8000 miles, last one was about 3000 miles prior. Car is back at the dealer today (again).

In my experience, the Audi G-001-700-03 HD6-C additive doesn't help and neither does the 'spirited driving' technique. See my update here:

http://www.audizine.com/forum/showth...=1#post5489076

[Tanner]

Audi's process in troubleshooting this is first using additives to determine if the injectors are dirty. That did help me a few years ago. Hard driving from time to time only helps to delay the problem from occurring as long as possible to the point where the intake valves needs to be cleaned by hand.

What I do know is that the CEL seems to come on and flash if the misfire count on a cylinder exceeds 100. You will get misfires from time to time but they're low enough that it's not an issue at all. If you're driving around and feel the misfires, get off the throttle, coast a bit, and it'll reset the count back to zero. Only found that out when I was logging the misfires via the ross-tech tool and when one of the cylinders exceeded 100 misfires, the flashing CEL then came on. Of course the CEL could come on if there's a big misfire I imagine. :)

[homieelee]

having the same issue. i didn't even know something wrong was going on. I had no rough idles other than one start the tach dipped a bit but idled right back up. No power loss.

'08 A4Q3.2 6MT bought CPO at 23k. I got CEL at 28k, car is at the dealership now. Service manager reported back of cylinder misfires and are in the process of cleaning the valves due to carbon buildup.

I would say I have driven this car pretty heavily. Easier to sustain higher revs and hard acceleration since it's a manual. however after reading this thread it's disappointing to hear that we MUST drive the car hard, and even then it might not help. just seeing that there is a MEGATHREAD on carbon buildup is enough to make me angry at audi. hope there is a solution to this soon.

[Tanner]

No there won't be a solution from Audi.

All you can do is probably put in a catch can which should delay the issue significantly.

[ossodiseppia]

This is indeed disappointing as I am contemplating a 3.2 Avant. The car that I am considering has been in the shop multiple times for this issue. Fuel additives and valve "cleaning" were the fix each time.

The vintage cars I drive are notorious for carbon build up because most owners putter around in them. The fix has always been an Italian tune up which involves some very spirited driving.

So, I'm wondering if the spark plugs are not hot enough and if there is a hotter plug that might help.

[Tanner]

So, I'm wondering if the spark plugs are not hot enough and if there is a hotter plug that might help.

Nope. Spark plug doesn't make things hotter, it's just a spark to ignite the fuel/air mixture. Oil vapour in the blow-by gas is the issue which collects on the intake valves. Oil vapour separator isn't up to the job really in our 2.0Ts so catch cans help considerably. Though it's not 100% effective either due to valve overlap but it delays the issue much longer.

[ossodiseppia]

Thanks for clearing that up. I've been reading thru the carbon build up thread. There's lots of chatter about additives. Then, there is the BSG treatment. Someone even commented about the old school method of ice water. The old school method I learned was to dump ATF into the carburetors. That stuff is caustic and does a great job of cleaning valve deposits.

I really like the Avant and I want a 3.2l. But now, I'm getting cold feet about getting one. My VW with the 24V VR6 has been a great reliable car. All I do is change the oil and filter every 5k miles and drive it.

[Tanner]

I paid say around $700CDN to do the cleaning on my turbo four. on a V6, it'll be a bit more obviously but if this is done every 50-60,000 miles, it's not that big of a deal. Just a minor nuisance cleaning, so if you plan on not forever keeping the car, plan on getting this maintenance thing done once at least.

All newer cars are going to direct injection, nothing out there right now is totally foolproof in mitigating the buildup on the intake valves. Even Toyota's approach, using a secondary port injector to spray the intake valves once in a while to wash it, isn't a 100% working solution. Mini Cooper S's with the turbo engine has the same buildup issue too as it's direct injection also.

[Euro Vs Earth]

I have the wonderful 3.2 as well. Now this problem does seem like a design issue that should be dealt with accordingly. I've heard just about everyone with a problem with the carbon build up runs high test gas.
Does the problem lay with bad gas, not high enough test gas (93+), or should we just all pool our resources and hunt us down someone who will help us find/construct ourselves some awesome Heads and through in a sweet cam.
Jeez lets let our voices be heard and flip the stigma about the 3.2b7 being the black sheep in the tuning world... Anyone?

[Tanner]

It's a inherent weakness with all direct injection engines. I've been running shell v-power since day one and still had to get the intake cleaned at 102,000km. There is a solution right now that will resolve most of this issue, it's called a catch can.

[ossodiseppia]

I have the wonderful 3.2 as well. Now this problem does seem like a design issue that should be dealt with accordingly. I've heard just about everyone with a problem with the carbon build up runs high test gas.
Does the problem lay with bad gas, not high enough test gas (93+), or should we just all pool our resources and hunt us down someone who will help us find/construct ourselves some awesome Heads and through in a sweet cam.
Jeez lets let our voices be heard and flip the stigma about the 3.2b7 being the black sheep in the tuning world... Anyone?

It's not a design issue as most think. This is really just the nature of the beast. Read through this entire thread and you should get a better understanding of what's causing this issue.

This issue seems to be very common in all direct injection cars. I've been snooping around a few forums and have read complaints about Mini, BMW, VW and Porsche. I am sure there are others.

Blow-by gases are sent through the intake to be burned in the combustion chamber. This, I think, has been done since it was mandated by the US Federal government in the late sixties. Other countries may have adopted this. These blow-by gases contain oil vapor. The oil vapor sticks to the back side of the valve and the valve face.

In a multi-port injection engine. gas is squirted on the back side of the valve to get the gas (and air) into the combustion chamber. This delivery method is sufficient to reduce these deposits. When these deposits do build up, a fuel additive works to help reduce them. I prefer the Italian tune-up method over this.

Direct injection engines squirt directly into the combustion chamber. Therefore, no gas hits the back of the valve. So, there is nothing to reduce these deposits or keep them from forming.

Some folks are routing the blow-by gases to a catch can. When the oil vapor hits the inside of the can, it condenses and is collected in the bottom. From time to time, the can is removed and drained.

I own two vintage Alfa Romeos. Both have an oil vapor recovery system. The oil vapor is separated and returned to the crank case. The gases get vented into the air cleaner.



I hope this helps.

[A4 Centaur]

Hey, I saw something years ago that you would spray into the head and let sit for an hour or so. Then you would replace your plugs, and fire the engine back up WOT for a spell. I think it was designed for boat engines?

[ScoGold]

Was all of this covered under warranty or Audi Care?

I just purchased a CPO A4 3.2 B8 and am at 18k miles. Do you think performing an oil change every 5k will prevent the Carbon Buildup?

Sorry for the noob questions.

[WasGTIguy]

I just had the carbon cleaned out last month. My engine light was on and sent the car in. My injectors were soaked and had carbon build up. The car had 70,000km and was done under warranty

[Tanner]

Warranty and CPO will cover cleaning. Changing the oil that often won't really help prevent carbon buildup, because that's what I did more or less.

[wackogracko]

Im about to get a '08 2.0T S-line and it has 28k on it. Does anyone have a rough estimate of the mileage that carbon buildup is starting to occur at for the 2.0T? It looks as though the 3.2L are happening before or around 20k, and definitely before 30k. The reason I ask is because if I purchase the car, it only has a year left on the warranty, so I am debating whether I should wait to get the extended until just before the factory warranty runs out or if I should tack it on right now. Thanks in advance.

[Tanner]

A large factor is driving style. It seems that a lot of short drives will bring the issue sooner vs later, while others that drive continuously for quite a while (to the point that the engine is properly warmed up) the issue comes later. I know of a 3.2L owner that has probably 70-80,000 km and no issue. I had issues starting around 95,000km and had the intakes cleaned shortly after on my 2.0T.

Cleaning a 2.0T from the dealer if I recall, was just under $700CDN taxes in.

[wackogracko]

Thanks for the info. Most of the driving I will be doing will be 20+ min on the highway, but I need to inquire what kind of miles the previous owner put on it and whether or not they were commuting or driving around town. The clutch feels a little soft (it catches right at the end of the stroke of the pedal) but the thing that I'm a little worried about is the engine seems to have a pulse to it, like mentioned at the top of this page. Is this one of the symptoms of carbon build up or is it related to the PCV valve or cam followers or something else entirely? Thanks again in advance.

[Tanner]

Based on my experience, when the intake valves are in bad condition, you'll feel the engine stumble on a cold start. Drive off slowly, and the stumbling will continue. Once the engine warms up, the stumbling will lessen but it'll still occur, but just not as frequently, as shown below when I was tracking the misfires on each cylinder before I got the intake valves cleaned.



Cam issue - that's a different beast. If you're full throttle and the engine stumbles at high RPM, it's a good indicator that there's a problem with the HPFP, which could then indicate that the cam follower has completely worn through. It does seem that people that are chipped will run into this issue sooner than others that aren't chip, obviously because of the higher demand on fueling.

As for the pulse, if you're talking about that noticeable tick, that's the high pressure fuel injector.

Clutch - if it catches up really high, clutch is probably on it's last leg. It'll start to slip if you accelerate hard in 5th or 6th gear on the highway, otherwise if it isn't no need to worry about it until it happens.

[wackogracko]

Yes, its definitely the "noticeable tick" you are referring to. So when you say "thats the high pressure fuel injector", does that mean its operating normally that way or is there something going wrong/bad with the HPFI? Thanks.

[Tanner]

Yes the ticking is the high pressure fuel injectors, see the below video from APR:



Of course there are other ticks that the engine makes :)

[a4b7qtro]

20,000 miles on my '08 A4. No issues yet. but I try to do track days 2-3 times a year. The tail pipes are coated w/ black at the end of these...... I think drive hard and hot occasionally seems to be the answer. My daily driving is less than 10 miles and barely gets the car warmed up.

[buellwinkle]

My 2008 A4 3.2 is reaching high miles, 13.5K and it got it's first check engine light (P303 and P305) and yes, I drive the piss out of it, mostly long drive, but infrequently, for example, I'll drive it 75-85 miles one way, but may not drive the car or a few weeks in between and mostly 80mph (typical CA freeway driving). We'll see what they do. I could have reset the code, but I want it on file that they did because the warranty is up soon, and they would have to own up to it if they didn't fix the problem on the initial visit. I'm thinking of getting the Audi extended warranty. Would this be covered or are they calling it maintenance, because to me, to call it maintenance, it would have to be described in the maintenance manual, no?

[Tanner]

Cleaning the valves I believe is covered under CPO as I recall reading RS4 guys getting it done under CPO. Definitely leave the code there and don't reset it.

[buellwinkle]

The dealer clarified that if there's carbon build up on a car with high miles, for example 80k-100K miles, that may be considered normal build up and that would not be covered (not that the warranty goes that far). But I said my car has 13K miles, if I was on the extended Audi warranty would that be covered if it causes misfire codes, he said yes. I checked on costs and he said about $1,200 to take the intake off and scrape the valves and $300 of that is parts like gaskets. To do a the BG treatment that some mentioned is $276.

[Tanner]

At that mileage, i'd just get it cleaned vs trying the BG treatment. The treatment IMO is good if the valves are relatively clean, more as preventative, but when there's enough buildup to cause misfires, a good scrubbing is required.

[Kai@EliteMS]

We've done many 3.2 carbon cleanings, unfortunately it's there. Here are some pics. The 4.2 FSI has been very popular with this service but essentially all direct injected motors suffer from it.

This link will take you to our Facebook page and goto a album there regarding the RS4's includes some before and after shots.
http://www.facebook.com/#!/media/set...9448533&type=3

These are some 3.2's

[Pasquallies]

This is why I always put 93 octane in and add a carb/injector cleaner to every 3rd fill up on my B7 3.2

[Brooks2]

I bought my 2008 B7 3.2 new in Pennsylvania. While I lived there, my commute was short and slow (PA slow, really slow). I developed the miss fire problem. I read about it in Audizine and tried the flat out accelleration cure. Initially, this caused a cloud of smoke for the exhausts. More spirited driving meant no more smoke and no more missfires.

Last summer I moved back to California. I drove from Massachusetts to California. Much of the time was spent at engine speeds over 3,000 rpm. In the West, this meant driving 400+ miles between gas stops at relatively high rpm. Back in Cali, I have been doing a lot of driving on 101 between San Luis Obispo and San Jose (posted speed limits are 65 to 70 most of the way). The car passed CA Emmisions with no problem at 77k.

The problem occured with my 3.2 B7 when I was driving short distances in congestion in PA. I have not had the problem with most of my driving at California highway speeds. This is my experience (it may not be typical.)

[mr larry]

For anyone who is wondering what Audi has already and/or may be working on to incorporate into our engines to help alleviate this problem, feel free to read their patent for it. It's a little tough to read but makes it pretty clear, to me at least, that nothing short of incorporating additional injectors pre-intake to wash the valves with fuel is going to work since the timing overlap and blow-by recirculation system isn't going away.

http://www.google.com/patents?id=fLI...page&q&f=false


This thread also has a promising solution to the buildup by bypassing the PCV system and dumping it into the exhaust (instead of a catch can), but that's only realistically going to work for someone that lives in a state without emission testing.

http://forums.vwvortex.com/showthrea...ghlight=bypass