I have '96 C280 that has been a prince to own. Bought it used and aside from some minor issues, it has run smoothly.
Within the last month the car has been reving slightly in idle. I start the car, in park it will rev over 10rpm and then back to 5 or lower. It will continue to do this for a short time and then subside. After another brief period it will resume. It doen't do this in drive, just in park. Any ideas as to what might be the problem?