560SEL Idling Problem Update: Continued appreciation for the suggestions - particularly from Avatar, JNT, and Cool. I have spoken to the MB mechanic and, sure enough, he had considered doing the smoke test on the intake to check for vacuum leak(s). Unfortunately, I have not been able to get my 560 to the place where your suggestions will be reviewed. The weather is the N.E. has been lousy, and I have been driving my Land Rover. Hopefully next week (02/26), I will be able to take the 560.
Will be back to you with results.
Continued appreciation.
Kilyab