Have Mercedes Questions? Ask a Mechanic for Answers ASAP
can you describe the noise a little ? is its a squeal or a rattle , whereabouts on the engine is it coming from? does it rise and fall with engine speed?
Ok if its a high light noted rattle that seems to originate from the front of the engine and also gets louder if you remove the filler cap then yes its likely to be the timing chain
these engines have a hydraulic tensioner element that can be a little slow to 'pump' up from cold and so you can get a brief rattle from cold
it can also be alleviated with a change of oil grade
as depending on how hot your climate is then this will effect the correct choice of oil grade
if its cold ( sub 10deg C) then the engine should be running the thinnest recommended grade of 5w30
if you're currently on one of the thicker grades 5W40 or 15W40 then I'd suggest to try come back a grade
if you can tell me what you're running at present I can make a specific recommendation
Hi im kevin do you still need assistance ?