Originally Posted by e92_m3
I really feel like getting an RS4 for my next winter DD. Since the '08 RS4's were the last ones to be imported in the USA, I really wanted to add that car in the stable for Lake Tahoe, Reno trips during the winter.
Not pretty sure if I can bare with the carbon build up problem and opening/cleaning the engine every 20K miles.
I've been lurking in the RS4 forums and all they found was a catch can or the recirculating unit as the solution. The latter does help, but only by a tad. Has anybody found a fix yet?
Nope, no fix. It is an early direct injection design and the carbon buildup is a result of several factors. The catch can addresses the issue of fuel getting into the crankcase and breakdown products reentering the intake through the crankcase venting system, but the greater culprit was the amount of valve overlap and the exposure of direct injected fuel to hot exhaust gases. It is not an issue apparently with forced induction direct injection motors, and Audi has since made some design changes to their NA direct injection engines (although I haven't kept up with this since leaving the Audi scene). I actually did my own carbon clean and posted details along the way up on Quattroworld. That carbon gunk is messy and you do lose some power as a result. Cleaning it is a straightforward but tedious process. You just have to look at it as a 20,000 mile "service".
That said, I have never had as much fun doing anything in any car, at any time, than I did driving my RS4 with 4 snow tires in a foot of fresh powder.
Not me, but you get the idea: