Is carbon build-up really a deal-breaker?
 

Doing my research, looks like addressing the carbon build up is a $800-$1k job done every 20k-25k miles. If that's really true, what's the big deal? We pay more than that in tires for half those miles.

I'm sure I'm missing something, but someone please educate me :-)

I'm a B8 S4 daily driver looking to make the switch.

Not sure. I have 29k miles on mine and no carbon cleanup yet. The car feels as strong as ever, but if it ever needs the cleaning, I am willing to have it done. This, because it's the best car I have even owned. :)

I know lots of guys that went from a B8 S4 to a B7 RS4, but only one that went from an RS4 to a B8 S4.

Carbon buildup would be a deal breaker for me if it was known before placing the new order. But for a used car, I think it's worth it to clean every 10K miles DIY 13 hours of dirty back-breaking labor, or even pay about a grand for someone else to clean it out . Yes that's a lot of money, but not out of line with other exotics like Porsche, Ferrari, etc. The exclusivity, solid build quality, and overall balance of the B7 RS4 makes the carbon problem livable, but not forgivable. Audi fvcked up and they refused to admit it to me, even though I had high-res carbon porn pictures from my car to prove it. For that reason alone, for my next car I will return to BMW. But not until I put a few more serviceable years on my RS4. It's an awesome daily driver!

But honestly, what is the difference between carbon build up and a nagging RMS leak in a 911? You don't see a lot of people complaining that Porsche really screwed up. Maybe comparing a RMS leak and carbon build is apples/oranges (since the RMS is less of an issue if you drive the car more, from what i've read), but it just seems like SUCH a big deal for something that's an easy 800 dollar fix every two years.

Compared to a GTR's brake job ever 20k miles for $5-8k, this carbon clean up seems like a steal for this kind of performance/practicality, and for an issue that **MIGHT** show up every 20k-25k miles.

Well, you just answered your own question and I agree. Most people forget that grass is always greener on the other side until you actually walk over there. I had four BMW's from 1993 to 2004 and every one of them had electronic problems at least twice a month. Yes, they were all fixed under warranty, but the dealer is not necessarily a good second home. Thank God for Bangle because I cannot stand the looks of any BMW these days and I understand they are not much better in terms of reliability. Now, I am on my fourth Audi since 2004 and have not had one that coughed yet. If and when the carbon cleanup time comes, I will treat it as another unscheduled service stop. ;)

Mine has 40k on it now and still pulls very strong all the way to redline. No sign of rough idle or anything like that. I suppose I may have some carbon build up. But if it weren't for these forums, I would never have one bit of suspicion that anything was wrong. Car seems to run perfect.

If I ever do develop a rough idle or weak spots in the powerband, I won't hesitate to pay the $1k to have it cleaned. When you consider brakes and tires for this car, it's just a drop in the bucket.

meh...clean the carbon every 15,000 miles. It's really not worth fretting about.

from the looks of it, there may be a solution for it (to at least temper it) in the next 24 months, so don't let it get in the way of a killer car purchase.

A solution is coming? As in permanent fix? Will it be a recall? More info please...

There has been talk on forums about JHM developing a solution.

These days, BMW is so bad in terms of reliability that they make old and especially new Audis looks like Lexuses of old by comparison.