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The question you should be asking is not if all of other cars you listed have this problem (because they all probably do), but why aren't we hearing more about these issues from other car owners.
And the answer is simple... because there are very few people with our engines that will actually invest time and money to research this problem.
As said earlier, the RS4 car-nuts have discovered this through cracking the engine open and doing before and after dynos. Aside from myself here and maybe one or two other members I do no know of any S6/S8 member who has consistently dyno their vehicle to determine power gains/losses.
I think there is a time when most of us here have an issue with cold starts, engine lights, or misfires, but those issues are quietly addressed by the dealer who does the bare minimum to keep the engine light from coming on.
Unless you ask, read, look, and dyno, you may have a bad case of carbon buildup that robs your car of power and not even know about it... until you press the gas that is and notice that your V10 is acting like a V8, V8 like a V6, and so on...
Originally Posted by Sox6
It would be interesting to note what some contributing factors to this issue might be:
Do all of the Audi v10's have this issue? Would there be any reason that the S8 and R8 guys wouldn't be having this problem - if so, why not?
Does ethanol based fuel have any additional adverse effects? I know that in high efficiency marine motors it is almost mandatory anymore to use a fuel stabilizer like Stabil blue to avoid problems with the motors - could that be the case with our engines. Would we benefit from using pure gas, or stabilizing ethanol based fuels?
Are the guys that have had a tune done experiencing this issue more or less than non-tuned cars?
I know we are all kind of grasping for answers, but it would be nice to see some kind of patterns emerge and figure out if there is anything we can do differently to avoid decarbing our motors every 15k miles.
The only way fuel quality or compound could cause this mess is...
1. It's introduction into the oil through blowby, and then being introduced through the pcv system to the intake manifold, correct?
2. Through and egr system, being of unburned fuel re-circulated back into the intake manifold.
Guys, how would fuel quality enter into this problem other than one or both of these two ways?
Have any of you guys had to do emissions testing with this condition? Does the car pass? I read my owners manual and warranty information on my 2011 2.0t, and if I remember correctly, the government emissions warranty has actually been reduced to something like 6 years where previously it was 10....I think...
The question you should be asking is not if all of other cars you listed have this problem (because they all probably do), but why aren't we hearing more about these issues from other car owners.
And the answer is simple... because there are very few people with our engines that will actually invest time and money to research this problem.
As said earlier, the RS4 car-nuts have discovered this through cracking the engine open and doing before and after dynos. Aside from myself here and maybe one or two other members I do no know of any S6/S8 member who has consistently dyno their vehicle to determine power gains/losses.
I think there is a time when most of us here have an issue with cold starts, engine lights, or misfires, but those issues are quietly addressed by the dealer who does the bare minimum to keep the engine light from coming on.
Unless you ask, read, look, and dyno, you may have a bad case of carbon buildup that robs your car of power and not even know about it... until you press the gas that is and notice that your V10 is acting like a V8, V8 like a V6, and so on...
On Friday, mine is going in for a dyno at EnzoRacing and then TyrolSport is going to open up the engine and take a look so that if there is a carbon issue we have another set of dyno graphs documenting the issue. I don't think I have a significant carbon problem but I also don't trust that I can just perceive the performance loss until it gets to be very significant. The thought that carbon could effectively rob 70hp (crank equivalent) is criminal.
On Friday, mine is going in for a dyno at EnzoRacing and then TyrolSport is going to open up the engine and take a look so that if there is a carbon issue we have another set of dyno graphs documenting the issue. I don't think I have a significant carbon problem but I also don't trust that I can just perceive the performance loss until it gets to be very significant. The thought that carbon could effectively rob 70hp (crank equivalent) is criminal.
Would be Very interested to know how long it takes to pull things apart...let us know!!!!
As mention before I choose to install a catch-can in my car to help fight carbon build up. Well stop by the shop today to change the oil and check on the catch-can and to my surprise the catch-can was full. The shop empty the catch-can and change my oil and the results were, after driving 3500 miles they pull out two small cups of coffee full of a mixture of oil and gas. In my opinion that a large amount of fluid for 3500 miles of mix driving between city and highway and pushing the car sometimes. This is just a sample of the problem with the FSI technology which is being adopted by more and more automobile manufactures.
It was mention on previous message that Audi already has oil separator, but my question is “where is oil going in the separation method from Audi”?
so the catch can is the answer? is threre any other approaches? how DIY is the procedure of taking off manifold and cleaning build up? I saw some black marks on the throttler body when I took it off for cleaning. Is this an indicator of a bigger problem?
that been said, I would not complain about FSI technology as such. IMO my 3.2 FSI engine is great even if I will need to clean it once in a while. non FSI motors are not in the same league of power output. and I save money on TB changes any way.
Thanks so much for this post. I'm so glad to find your post. It all makes sense. I have a 2008 S6 which I purchased brand new from a dealer here in Newport Beach CA. I have taken the car to the dealer 3 times from the time of the purchase for this same reason. I run into this problem the first time in 2010 with mileage of less than 20K miles. When I took the car to the dealer, my injectors were replaced. The car was under factory warranty, so repairing was not a problem. Just about a year later, I run into this problem again. This time around, the dealer was not willing to repair the car without having me to pay for the repairs. The car was out of factory warranty and the extended warranty was not willing to cover the charges as well. carbon build-up was and is considered an external element and not related to part defect. So I had to struggle with the dealer. I managed to have them clean out the valves but that didn't last long. It only lasted for two weeks. The problem is back and I'm back at the dealer again. First, I was trying to figure out what's really going on because nothing made since. But now, everything makes perfect since. I believe this is a complete rip-off and bad business practice by both Audi and the dealers. Something has to be done to stop them.
If you're out of warranty or have an aftermarket warranty (i.e. Fidelity), I think you should head up to Long Beach and have Raven MS check out your car.
I don't work for them but have gone to them for all of my previous needs (on my old Audi A4 Avant).
Now that I'm in a C6 A6 Avant, I go to them for guidance--but I'm CPO for some time so they provide me with the proper info so that I can tell when the dealerships are trying to feed me BS.
This car is a little old but even so a few are still out there.
I wanted to say that while I applaud what DirtyVegasTT has published here with his now-sold car, I disagree with the thrust of several comments and the overall blame to carbon buildup. Even with the cleaning he was still only getting like 350 hp to the wheels from a v10 5.2L engine. Companies like to make money so sometimes they do price discrimination. If Audi is one of those companies they could be like AMD. AMD didn't want to pay for having multiple dyes so they detuned the cheaper cpus. Hackers eventually learned they could use a pencil to re-bridge the cheap cpus to get to higher clock speeds (of their premium cpus). A v10 5.2L should make not 290 hp nor 350 hp but 525 hp of the Audi R8. In that spirit, one wanting more power from the S6 should perhaps disassemble both the R8/lambo engine version and the cheaper Audi S6 engine and note what all is different. I'd see if the intakes can be swapped. Remove the split pin crank and see if the non-split crank fits. (Can't be good for the redline is my theory.) Use the lambo or RS6 or R8 ECU and see if it works. And so on. I am guessing the block could still be used but I wouldn't bank on keeping much more.
In short, if you don't like a detuned engine cleaning it won't help much. You have to un-de-tune it. Chances are once you fix that the carbon buildup won't matter as much in the first place.
12-31-2010, 04:13 PM
