I Have some questions and I am hoping some of you Auto Board experts can give me some Yoda like guidance. I used to have an 2005 Audi A6 with the 4.2L V8. Like a maroon, I sold it and bought something else. Now years later, I am yearning for another Audi. So as I am doing my research I run into a lot, I mean A LOT of webosphere chatter on carbon buildup issues on the backsides of the intake valves, valve stems and ports. It apparently affects every VW and Audi engine that uses FSI (Fuel Stratified Injection) meaning direct injection into combustion chamber. Apparently, not having the fuel/air mixture flow over the intake valve as happens in a manifold injection system allows this carbon buildup to happen. From what I can tell it affects the 2.0T, 3.2 V6. 3.0T V6, 4.2 V8 (from 2007) as well as the 5.2L V10 in the S6. Apparently Audi has notified owners of Audis with the 3.2L V6 and 3.0T V6 that they have extended their warranty to 10 years/ 100K miles.


So sorry for the long background, but having lurked on many enthusiast forums I know that typically problems get blown somewhat out of proportion as typically only those with problems post about it. So is this a big deal? Should I avoid any VW/Audi with FSI? What say you auto board?

Some links about the issue:

http://www.redlinespeedworx.com/v10-s6-carbon-cleaning/

http://www.edmunds.com/autoobserver-archive/2011/06/direct-injection-fouls-some-early-adopters.html

audi fsi carbon build up

I had an A4 with the 3.2 V6 and was never too woried. If I wasn't dumb and sold it for a newer one Id still be driving it. While this issue is annoying, you can get it cleaned for not too much or do it yourself. I have some before/after pics somewhere if I can find them when it was cleaned around 100k miles.

Edit: I'll add that I think the turbo/sc engines had less of a problem bu I'm no sure.

It's an issue, but not a reason not to buy a car you like.

It affects even us turbo'd FSI/TSI cars. Like Secret mentioned, it's not difficult to clean it up, and there are ways to make it almost non-existent (run methanol injection ).

I've seen my internals, and at about 66k they looked almost new. THANKS METH!!!!!!!!

quote:

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It's an issue, but not a reason not to buy a car you like.

It affects even us turbo'd FSI/TSI cars. Like Secret mentioned, it's not difficult to clean it up, and there are ways to make it almost non-existent (run methanol injection ).

I've seen my internals, and at about 66k they looked almost new. THANKS METH!!!!!!!!

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Thanks guys. OK, but if I buy an Audi and it starts doing Meth will it eventually look all skanky like a late 70s Oldsmobile Toronado?


olds7701.jpg

HAHA, of course it will.

FTR, the new Mk7 (in Europe) gets the best of both worlds where they mix direct injection and the "old" method (port injection), to keep this problem from happening. Of course, we don't get that here in the States.

BMW has this same problem. You pull the intake off and walnut shell blast the valves every 30-40k miles. Meth and oil catch can help between cleanings. Just part of the engine design. Dealers charge 600-800 to do it. Indy did it for me for 400. I did it myself last go around. Very little money for tools. Just a lot of labor involved getting to the valves.