W124 engine noise

[Bert Lad]

I have W124 E220 which jas 160K miles and has had regular Mercedes svce . I am told ithas a type 111 engine . I am getting a droning sound from the engine - it seems to be coming from the front of the engine at top somewhere near the Oil filler cap area. Some say it is timing chain , some say it is timing chain tensioner and some say its hydraulic valve guides - The timing chain (duplex) was changed at 120K miles and so was the timing gear which is attached to the righthand cam.Also changed was and Crankshaft sprocket. The noise seems to more prevelant when engine is cold .Any clues ??

ALso how easy would it be check/change the timing chain and tensioner ??

Thanks - Bert

 

[tom7035]

Slack timing chain or worn hydraulic tappets I wouldn't describe as emitting a 'droning' sound - rather a 'rattling' or 'clatter'. I suspect elsewhere for the culprit. Someone else may have a view on this.