Hokie_Audi

Hello everyone, just putting some more data out there on the FSI carbon build up problems.

Some back story on my 2008. I'm working from memory here but I can provide more detailed records if anyone is interested once I have access to my service logs.

For my car the carbon build symptoms present themselves when the car is started cold. When the car is in the fast-idle stage of warmup you will first feel a little rumble as the engine misfires. The intensity of the rumble/shudder will increase progressively over a number of days until finally the car throws a CEL for misfires. There appears to be a mis-fire count threshold that must be exceeded to trigger the CEL. Once the engine is warmed up the misfires and attendant rumble/shudder go away.

In the inital stages the CEL will clear after a few days, only to return on the next cold start. Ultimately the car reaches a point where the misfires and shudder occur every time and the CEL stays on. This is particularly true during colder weather.

My car first started misfiring and throwing CELs after about 5000 miles. Initially I was advised to use Shell gasoline (which I already did). They cleared the codes, sent me on my way and the problem occurred again a few months later. Came back in, this time they did the injector cleaning guided fault finding procedure, advised to use Shell, blah blah blah and provided me with a bottle of injector cleaner to use at the next fill up.

Around 25,000 miles my local Audi dealer received the enhanced instructions for diagnosing and curing misfires which include instructions to remove the intake and manually clean the valves. This was done around the same time as my 25K service in November 2009.

In September 2010 my car started to shudder again and the intensity built up to the point that CELs would be thrown. I was due for my 35K service in October, took the car in with a CEL, dealer confirmed that it was misfiring but noted that all the TSB "fixes" for the problem had already been applied. They cleared the code and advised me to watch for it and bring the car back in if it continued, which of course it did.

CEL is on constantly now once again, shudder is noticeable on all cold starts now that we're dipping into the 40s in the morning and I have an appointment for them to do the intake diagnostic on Monday November 15. I fully expect that the car will need to have the intake removed and the valves manually cleaned once again. I informed the Service Advisor that I would like to speak with an Audi rep about a written extension to my warranty to cover this issue since this is an on-going problem with the engine that's obviously related to a design flaw or oversight in how the FSI engine works.

Pertinent observations from my own experience:

Gas quality doesn't really matter, which is something that many have understood for a while now given how the DI system works and where the deposits are occurring. If the problem were injector blockage or deposits building up in the cylinders it would be a fuel issue.

I have started saving my gas purchase receipts, just to head off any conversations about the quality of fuel that I'm using. "Are you using Top Tier Fuel?" *break out book of Shell V-Power receipts* "Okay, we can check that one off."

I have also stopped using Ethanol dilluted fuel whenver possible. There's a Shell station near my house that offers ethanol free V-Power Premium. This probably won't help either, but at least I get better gas mileage and I suspect that the engine is designed to "tolerate" ethanol dilluted fuel. I recall the manual saying something about switching to non-blended fuel if generic issues occur, so I've switched.

The ECU update to modify how the engine operates was done on my car at least 10000 miles ago and this doesn't seem to have helped.

Audi doesn't have a solution in place, only a maintenance plan at this point.

The cleaning operation book value significantly underestimates the time that is actually required to do the service. I say this based on the service department manager griping about how hard it was to do versus how much they were allowed to charge to warranty work. I suspect this means that out-of-warranty owners will get reamed on this work.

The buildup occurs quickly after cleaning (less than one year and less than 10,000 miles for me between cleanings and initial CELs for the current episode).

Some have suggested that driving style and duration could be a contributor. As a datapoint my typical commute is about 10 miles each way, four to five days per week, partially on suburban roads and partially on a 55 mph two lane. I try and get into the throttle pretty deep in sport mode at least once a day and run the engine up to 6K or so after it has warmed up. The Italian tuneups don't seem to help, but they are fun.

I expect to hear an answer about my warranty request in the next few days. I'll report back on what Audi says. De-carbing the intake on FSI engines is essentially a regular maintenance item now.

Pete@ECSTuning

Subscribed. I didn't know you could even buy non-ethanolated gas anymore. What sort of mileage increase did you find with this? It would be great if they would extend your warranty to cover this specific problem.

Hokie_Audi

You have to look for it, but there are stations that sell it. You'll pay a little more per gallon but you also get more energy content per gallon. I used this website to find my Shell station:

http://pure-gas.org/

There's also some other search sites that pop up on Google. So far on long trips I'm seeing an indicated average that's 1-2 mpg higher than what I saw on fuel that was up to 10% ethanol. I was inspired to look for ethanol free stations by a recent report that the EPA was going to allow up to 15% ethanol concentrations in the near future with their [EPA] recommendation that it only be used in cars built after 2007. To me that's laughable since I doubt very much that extensive testing and qualification has actually been done by all makes across the board to allow E15 usage.

Leeladisky

I would be interested in your result being as I'm asking for similar related to my tranny problem. If enough of us ask for similar because of multiple trips to the dealer for the same issue or recurrent issues, maybe Audi will take a different approach. The problem is that if dealers aren't getting paid enough to repair a problem under warranty, they are unlikely to diagnose that in the first place. This is a catch-22 for owners and presents us with an overall customer satisfaction dilemma.

krustyx

My car takes forever to start when its cold.

I've been told its due to the carbon deposit also.

gk1

This sucks. Definitely keep us posted. I only have about 5k miles since my full cleaning. Your final sentence is what my dealership told me after having mine manually cleaned. "De-carbing the intake on FSI engines is essentially a regular maintenance item now." They feel it is a maintenance issue and NOT a design flaw. Which baffles me...Shell gas, Castrol oil, Audi fuel additive, what's next Audi approved air?

When I got on it hard the other day I saw the infamous cloud of carbon smoke in the following car's headlights. My normal driving style is not timid, so I was surprised to see such a cloud. I don't know if this is good or bad....the carbon is being blown out, but it means there is still carbon to be blown out!?!?

Does anyone know for certain if the European community is experiencing the same issue?

FWIW I've been using Redline SI-1 on a maintenance dosage since my manual cleaning. If for nothing else but to humor the service departmenet as they were insistant it was fuel NOT oil causing the carbon and that regularly running fuel injector cleaner would be good preventative maintenace... even though it is logically contrary to the basic functioning of the FSI motor. However I have no idea if it is doing anything at all. I'm also running seafoam through a vacuum line prior to my oil change coming up in a couple weeks. Again, my only way to tell if it is doing anything is if the CEL DOESN'T come back. Weak.

Pete@ECSTuning

Are you running conventional air? I believe that will void your warranty.

DirtyVegasTT

I am amazed how Audi is avoiding this entire issue by not acknowledging the design flaw and is leaving its customers with gunked up engines that underperform and malfunction. Audi has had an issue in the 1980s that destroyed the company’s reputation and caused them to pull out of the United States market. It baffles and frustrates me how a company can be so arrogant to ignore this issue with EVERY one of their current engines and not think that in time, once again, Audi will be stigmatized as having unreliable vehicles.

My S6 was robbed of probably over 10% of its power due to carbon buildup. I am waiting to put my car on the dyno after my next tune up to see the power that I got back after the cleaning. What also frustrates me is that even when the cleaning is warranted and done by the dealer they make it out to be as if they did you some sort of favor by addressing this issue.

This is all sad and pathetic. After having over 3 Audis in my family in the last 5 years, I doubt there will be any other Audis in any of our garages in the future. This sucks so much because I really like the S6 and the new S4.

mystrodo

I've never believed it was the fuel causing the carbon issues but rather the oil... Audi dealers were using, in my case exclusively Castrol, this may or may not be the appropriate oil but I do know there are new formula oils being made which if the hype is true.. should be more appropriate for our engines. I tried to stir-up some reaction to this new oil here but nobody followed so I just continued on my own as usual ..I'm using it BTW... although hard to find and alittle more spendy,I'll give a report at 5K then 10K but the dip stick is already showing much cleaner at approx the same mileage as the castrol.
http://www.pennzoil.com/documents/PE...ropean5W40.pdf

john_S6

I had the same problem at 54000 miles which caused the dealer to keep my car for a week to clean the valves. After that incident and much research I decided to install catch can in my car along with meth injection system. I'm not saying that the solution to the problem but should help keep the engine clean. After driving about 1000 miles the catch can was drained and about quarter of coffee cup of gas and oil mixed came out. But so far the engine is running strong and once I hit 3500 RPM the meth kick in then the car become a beast. The project is not completed but so far I'm very happy.