W124 e220 with Cam Chain Rattle

[d215yq]

Hi All,

Started the car today and heard for the first time a slight cam chain rattle for the first second or two which then disappeared.

The car is a 1996 model with 130k on the clock (and i presume original chain/tensioner). Should I be thinking of changing the tensioner or the cam chain and how much should these jobs cost at a good indie garage?

Also is it likely that the chain will snap immediately? - I see that some forum members believe that there will be much more rattling before the chain will snap and so what is the consensus on doing nothing for another 6 months and 6k miles until the next service is due?

Any opinions greatly appreciated!

 

[Bolide]

Are you sure it's not hydraulic tappet rattle? That typically happens in the first few seconds after startup

Nick Froome
www.w124.co.uk

 

[d215yq]

Are you sure it's not hydraulic tappet rattle? That typically happens in the first few seconds after startup

Nick Froome
www.w124.co.uk

Thanks for quick reply!

Not sure if its tappet rattle, how would I know if it was? Its a metallic rattle that occurs for first few seconds when cold only and then disappears completely as the oil pressure gauage hits maximum. There seems to be nothing else untoward at all and the car except it doesn't always start first time when cold (always starts second time). I don't know if this is related or not.

 

[Bolide]

Tappet rattle could come from any tappet. Timing chain rattle comes from the timing chain in the timing chest at the front of the engine

If it only happens when cold you have limited opportunities to diagnose it. I'd take it to your local independent, park it outside overnight, walk him to the car in the morning, start it up and ask him what it is

My money's on tappets

Nick Froome
www.w124.co.uk

 

[turnipsock]

Sounds like tappets.

What Oil have you fitted?

 

[MarkCL]

I agree with Bolide - this is where the experienced ear of a good indie can come in very useful - so many noises that we hear can be confused for other things. Whereabouts are you located? Have a look at the list of good independant MB specialists & find one in your area that will have a listen for you and let you know hopefully one way or the other which it is.

Cheers,
Mark