Reggie

Yep - and as a owner of the one car with the worst history of carbon build up (B7RS4) I have been following this issue for some time. I now look at it as maintenance issue like getting a timing belt done. So far I have not had any codes thrown and when I do I plan to get my valves cleaned.
All of the tricks mentioned (BG44k, top tier gas, meth, catch can,etc) have been tried on the RS4 and no results have consistently shown a fix.On shop has talked about a fix they are working on but nothing firm on hopeful promises.
I will say that the amount of carbon build up issues on the other Audi engines has not reached the same peak as the RS4 and may indicate Audi has made improvements.

Xpri

I had lots of issues with carbon buildup on my 2008 A4 3.2. The problems started at about 17K, just over a year into ownership. CEL would be thrown by engine misfire when cold, the misfire was caused (according to dealer) by the carbon buildup. Dealer tried to blame the gas initially, then tried BG44, then cleaned the valves, all of this over the next 15K or so miles. I finally gave up trying to improve the situation, ignored the CEL which came on often and returned the car at lease end. No problems yet with the Q5 but I'm not driving nearly as many miles as I used to.

uberwgn

Reggie, why is the RS4 motor so much worse than the others?

CinnamonQ5

How about Seafoam every once in a while?

ELEVENS

I'm not Reggie, there is no substitution for Reggie! But I'll give it a try....

CB is a result of four things: Valve overlap, crankcase ventilation, leaking valve seals, and lousy fuel. I think the reason that the RS4 was so vulnerable to CB is the aggressive cams with tons of overlap. On this motor, they should have either added a 9th injector on the intake manifold, went with external EGR, or both.

uberwgn

Makes sense. Thanks.

DennisM

This gave me some comfort when my wife wanted to get a 2011 Q5. The extended warranty gave me more comfort.

With so many years into this problem, I would hope that all dealers (and AoA) are in tune with it and will stop trying to blame the owner and cover the cleaning.

-Dennis

CrustyNoodle

I can't say I like the look of this but it is an alternative.

<iframe src="http://player.vimeo.com/video/3989681?title=0&amp;byline=0&amp;portrait=0" width="400" height="225" frameborder="0" webkitAllowFullScreen allowFullScreen></iframe><p><a href="http://vimeo.com/3989681">BG Fuel Induction Demo on Audi 2.0FSI Engine</a> from <a href="http://vimeo.com/user1532531">Siegel Distributing</a> on <a href="http://vimeo.com">Vimeo</a>.</p>

uberwgn

Good video. I hope those are actual before/after fotos.

This process looks very similar to the three step 3M kit I posted above.

Most owners are going to swallow hard when they're told they have to do this every 15k miles.

Presenter makes a good case for using the fuel recommended by the auto mfr (Top Tier, 91 octane or better) since some exhaust gas byproducts are re-burned (via EGR). Using the correct oil spec (low NOACK value) also plays a part in this mix of noxious crap being forced back thru the motor.

ELEVENS

Sorry but the BG cleaning is definitely NOT a fix for carbon buildup in Audi FSI vehicles and even BG has now admitted it, recommending a tear down and manual scraping off the carbon (while using BG presoak solvents of course). BG makes great products but a chemical does not exist that will remove the layered coked carbon deposits.