tidbittt

Will replacing timing chain tensioner on 2000 500sl w 92000 mi stop this metallic ticking/scraping on cold startup. Car starts and drives perfectly but tick is present until warmup temp is reached. Chain should be its tightest at cold temperature and 'elongated" somewhat at warmer temperatures. Any ideas on the reason for the noise and if you think this is a good starting point. Cant afford a new chain replacement at this time.

sutliffe

Sounds like you need to replace your plastic cam oiler guides with aluminum ones. See below


http://www.peachparts.com/Wikka/M119OilGuides

pjacobs55

If it's a 2000 SL500 then it has the M113 engine, ie no cam oiler guides. Get a stethoscope or use a long screwdriver (handle end to your ear ear) to listen to the purge solenoid . It's in the front left corner of the engine compartment, this link has photos of the exact location. Check out post 5 of this thread for a good explanation of what it does.
My 2001 r129 makes the same noise, which goes away when she warms up.
Hope this helps,
Peter.

Picture courtesy of FPC Euro

tidbittt

Thanks for the quick reply and extremely useful photo. I had hoped the tensioner might be a less expensive fix but the thread with the tensioner piston runout is probably my problem and the chain itself is "stretched". Gone from a 350 dollar problem to 2000. What I really wanted to hear was that this was an easy access fix with just a squirt of oil and I would not even get dirty. I wish I had never learned to spell Mercedes. (Owned 7 over the years). Thanks again.