'98 S500 valve train rattle at cold start up - PeachParts Mercedes-Benz Forum

peter210 · #1 02-22-2004, 08:36 PM

This winter during morning start ups I've experienced noticeable rattle coming from the top of the engine. I'm aware that oil drips down overnight and this may cause the problem. The noise dissapears few seconds after I start the engine. I happened not to drive the car for ten days. Whan I started it yesterday I thought that it will explode! Wow! Of course after less than 10 seconds it quieted down since the oil pressure built up. Are there any known problems causing this? My car is pampered. Oil change every 3K (Mobil1 5w30) Any suggestions? Please help before I take the top of the engine apart and find out nothing wrong....

Thanks...

Gilly · #2 02-22-2004, 08:49 PM

Is the noise possibly the timing chain rattling? Possibly it's the chain tensioner wearing out.

Gilly

peter210 · #3 02-22-2004, 08:53 PM

Very unlikely.... The noise definitely comes from the valve covers. BTW do you think the tensioner would wear out at 55K ?

Gilly · #4 02-22-2004, 10:36 PM

It could I suppose, If the engine has seen alot of city driving for example. If you are familiar with Hobbs or hour meters, think of the amount of "hours" that may be on the engine. A lower mileage car may still have alot of hours on it. I'm still thinking that's what it is, it can be difficult to tell without hearing it.
Another possiblity on the M119 engine are these plastic tubes called "oil bridges", but it should be clicking more than just at startup if that's what it is. By your description it's really what it sounds like though.

Gilly