View Full Version : 2012 s5

03-31-2015, 12:26 PM
Hi everyone. First day posting here. It's been over 10 yrs since I drove an audi (2000 A4 1.8T) and it was quite the lemon. Failed clutch at 20000km and repetitive faulty coil packs.
Despite this, I do miss driving an Audi.
As such, I'm currently shopping for an S5-used.
I prefer a 2013 but outside my budget. A 2012 is within reach however from reading this forum, the intake buildup is a great concern. Is this the only 'common' issue with the v8? Is this particular problem enough to just rule out the 2012? I understand I would be looking at a annual bill of $1000 to clean the intakes.
Any advice would be extremely appreciated.

04-01-2015, 08:25 PM
From what I read on forums carbon buildup is a certainty. It might need cleaning perhaps as early as 30k miles. So I wouldn't say it's annual but yea I was quotes $1200 so it's not cheap.

04-04-2015, 08:24 PM
Do realize that all FSI engines, regardless of manufacturer (GM, Audi, BMW, MB, ...) suffer from intake valve carbon build up.
Next/future generation FSI engines may alleviate this issue, but it hasn't been universally solved yet.

Using extremely high quality oil reduces this build up - "Top-Tier" gas has little or no effect on this since no gas or detergents in the gas flow over the valves to clean them.
From what I've read it's the exhaust gases that flow over the intake valves that cause this. Yes exhaust gases as part of the increased fuel efficiency/recovery design of these engines.

I have nearly 30,000 miles on my 2010 S5 and I do not yet feel the performance degradation due to carbon build up. I did feel it on my 2008 A4 3.2 6MT and took it in for confirmation and cleaning at ~60,000 miles.

My A4 is my DD, my S5 is mostly my track car with some DD use, so that may also play a part of this equation...


05-02-2015, 05:45 PM
I had been shopping for an S5, either a 2012 or 2013. (ended up with a new A5...) Mechanic (R8 cerified, knows his stuff!) at the dealership told me the best way to prevent the carbon build up is to drive the V8 car hard, in fourth gear, running at or near red line. He said to watch out the rear for black exhaust smoke to dissapate... (carbon blow-out). No build up reports or repairs on the V6 cars, pretty much bullet proof. I was told most of the S5 cars he has seen are city cars, with very little highway miles... which hardly ever reach WOT. As he said..."These cars are made to be driven... HARD!"