I have the same problem for years now. Knocking from the back while driving. Seems to happen more often in the winter. In the summer its quiet. It has its days though. Some days it knocks, others nothing and everything is fine.

I'm not sure what it is but I was guessing its the shock absorber or something like that. My car is 21 years old and I've never changed the shocks.

If you find out what it is let us know. I wouldn't mind fixing it if I know the solution. Now I'm trying to solve a hard to start problem, I posted about it but no-one answers...bummer!

-=>Raja.

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1983 MB 190E, bought from Germany and shipped to the US in 1986.