how to replace timing chain tensioner OM642

[@russtex]

Cheers and Beers!

[@benzblyat]

I just replaced the timing chain tensioner in my 2007 E320 Bluetec (W211) using your video, very helpful, thank you. To access the airbox, I just had to unscrew two torx screws (E10) and unscrew a hose clamp to remove the airbox. My tensioner fell apart just like yours when I removed it. I found it difficult to press the tensioner directly up into the engine, so I inserted a long flathead screwdriver in through the oil fill cap to lever the tensioner block (not sure what it's called, the thing the tensioner presses against) upward to relieve pressure that way. Once I did that, it was easy to screw the tensioner in.

[@delu85]

Can you please explain in more detail how you pressed the tensioner block! I tried for 3h today to insert the new tensioner but I failed miserably! I could not see the tensioner block through the oil cap, I have a C350 OM642 2009.

[@ClipperSurvival]

Maybe someone will find this useful. In the C350 I did not had much space, so I ended up removing the front right side wheel and plastic thing around the wheel. Still was very difficult to screw in the tensioner so I have slowly rotated the engine counterclockwise, I would say around 1/3-1/2 rotation. The chain became a bit slack on the left sider of the engine and I could screw in the tensioner carefully first by hand and afterwards using a ratchet and finally tightening it up to 80Nm. Finally I have rotated the engine clockwise about the same amount I did counterclockwise. The engine took 3 attempts to start, but started in the end, had a rattling noise for about 10min, afterwards I reved it to 2000RPMs and the rattling was gone. Car is working fine now, I have not heard the rattling again at the cold start.

[@dogshome7110]

Just did mine. R class with less room, although not bad. I see what you mean about jiggling the crank back and forth and you can feel the tensioner dropping in. It's still a cow to press and twist though. I did it by hand by twisting, pushing and jigging it about until it finally caught. 80NM is correct but is very tight! Thanks for your helpful video 😎

[@mytriton54]

Before you replaced it, did it rattle only on startup or more often?

[@ylliwashere]

should be only during startup.

[@ylliwashere]

if its all the time it’s timing chain problem 😬

[@S-u-p-a]

​@@ylliwasherewhy?

[@alidogansoy5650]

Ce moteur n’est pas un om642

[@Creek_Hunter]

I think it's a VM Motori.

[@crisp4558]

Il s'agit bien d'un moteur OM642.

[@alidogansoy5650]

@@crisp4558d’accord merci