I have a 93 190E 2.3L and when I put the thick oil 20W-50 this past June 2005 I noticed that the engine would on occasion idle and vibrate at a low rpm after initial startup and at other times it would idle low at a stop when the car engine was warmed up 100 C and had been driven for over an hour.
Is it the oil that is the problem or something else???
Any ideas?
CP