om646 strange noise. timing chain?

[mbbbm]

The car makes a clicking sound like a warm engine.
I have changed the multi-groove belt and rollers. But the sound is still heard. Is it the timing chain? do you have experience?

car is E200 cdi 2007 540000km

a couple of videos of the sound

 

[mbbbm]

The car makes a clicking sound like a warm engine.
I have changed the multi-groove belt and rollers. But the sound is still heard. Is it the timing chain? do you have experience

car is E200 cdi 2007 540000 kilometres

check to videos below.

Noise 1
Noise 2

 

[ajlsl600]

If noise does not go with belt off. Chances are chain. If need be go for chain tensioner first see wot sounds like after.

 

[Kudly]

Unless a typo, good mileage on your car

 

[M80]

The duplex chain isn't a known problem on the 646.
Tbh I've not heard that the tensioner is either, but many know more than I.

Is the aux belt tensioner in good order?
As said take the aux belt off and see if the noise is still there.

 

[ajlsl600]

Tensioner 1st for noisy chain. O ring gets dry oil passes tensioner stops working as designed but take beltoff 1st n check

 

[mbbbm]

thanks for the answers. The sound is still there even after I removed the belt.

 

[ajlsl600]

Well. Not belt or associated pulleys then. Me I would try tensioner.

 

[horatio]

There’s so much room to work on a 220 211… it shouldn’t be a huge job to replace the guides & tensioner (a pro can chime in here?). If this is the noise.

There’s a video about the merc duplex chains on YouTube (think it was on legit street cars), the bloke was saying they are basically indestructible and it’s better to keep the old

 

[rich.g.williams]

Could be the hydraulic valve tappets, they can get gummed up

 

[5w155t0ny]

I would say that isn't a tappet noise, but could be a worn pulley.
Doesn't really sound like a timing chain issue to me but that could be the sound quality on the video.

 

[rich.g.williams]

but could be a worn pulley

agreed - worth checking that the alternator (Overrun Alternator Pulley) pulley is freewheeling properly and not seized up.

 

[mbbbm]

Thanks for the answers!
The problem was resolved! The sound came from the chain

 

[jerzy]

Hello,
Was it fixed by the chain tensioner, or did you completely replaced the timing chain?