Originally Posted by sdeprima
Could carbon buildup explain why my car has a really rough idle at times? Typically my car idles at 600 rpm steadily, but more and more once the car has warmed up, the rpm's will drop to under 500 and bounce up and down as the car shakes. Could that be a misfire or carbon buildup? I'm taking my car in next week for service, just curious if you guys think I should mention this to my SA.
The misfires are most likely because of the carbon build up.