300sel timing chain tensioner
 

my car is a 91 300sel 178000 miles. when i start it in the morning there is a rattling like tming chain is loose for about 20 seconds then it stops no more noise the rest of day. could this be chain tensiner not pumping up properly?does any one else have this problem? also how do you rest tensioner when you istall new one?

Yeah I'd try a tensioner first. Just unscrew the outer cap and the spring will kind of pop out, so be ready for it (not hard enough to hurt yourself, just a bit of a surprise on the last thread). Then the main body can be unscrewed. To install you install the main body, then the hollow looking part (with the ring around it) ratchets itself into the bore (well, actually you push it in, it is 1-way, it won't back out by itself), then the spring goes in the hollow part and the cap is pressed against the spring until you can start the threads, kind of a beeyatch to install the outer cap. There are seperate torque specs for the main body and the cap. Also a seal ring for both of them too. It all comes as a kit.
Gilly