Does your alarm system work? The round plastic connector is probably the connection to the door handle. Most of the time this is unplugged to compensate for a malfunction in the alarm system.

If you have never had the heads off, it is past time for a top-end rebuild. It will cost about $2500-$3000, but it sure is better than replacing a whole engine. The bottom end almost never goes bad.

When was the last time you had maintenance done on the suspension? The self-level needs to be babied, i.e., frequent fluid changes, etc. Is it leaking?

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R. Downs
1985 500SEL (260,000 miles) SOLD!
1974 280 SOLD!
1994 Volvo 850 Turbo Wagon (Yuppie Ice Sled)

"I know I have a Benz and they know it too." If you start bragging about it or shoving in people's face, you then become a Wally; especially to the girls.