View Full Version : What causes carbon build up in the S6, M5...?!

07-19-2011, 10:17 PM
I am trying to understand what causes the massive carbon build up in the V10 S6, E39 V8 M5 and I'm sure other high performance engines...?!

Are we using the wrong gas, will additive on every fill up help, etc.?

07-19-2011, 10:34 PM
No direct injection is the culprit. There's no gas washing the intake valves. The quality of our fuel and oil also contribute/speed up the process.

07-19-2011, 10:45 PM
If direct injection is one of the culprits, we should be informed that a $8,000 carbon build up maintenance service is necessary in the service interval, anyone agree?

07-19-2011, 10:55 PM
$8k?? Go to another dealer. My Audi dealer told me to remove the maifolds and clean the valves it would cost me $400 in labor.... Yours is screwing you

Then again, I went in for a check engine light and my Audi Dealer Cleaned my Throttle body sensor for free and only charged me the... I forgot what its called, just where the Look for the problem...

Tons of Info about this all over the forum/net etc...

07-19-2011, 11:08 PM
$8k for the e39 M5 because the engine has to be pulled out to clean the secondary exhaust carbon build up.