Seems like alot of knowledgeable Benz owners here,hope someone can figure this out.I have a 1995 C220,for about a year now.It has 215000 km and no major issues with it,just changed the water pump and serp belt.When I rev it up quick and let off,there is a rattling noise only when revving it up fast and quickly letting off.If you rev up slow or constant speed,no noise.I have taken the belt off and it still does it.Sounds like from the top of the engine maybe near the back,hard to tell,I have tried listening with a scredriver or a hose and still can't tell exactly where it is coming from.Wierd thing is that it only does it when you rev it up fast and let off,doesn't matter if the engine is hot or cold.Any ideas or suggestions would be greatly appreciated.Thanks

 

kwinn.

The model your asking about may have a belt tensioner shock absorber which commonly becomes noisy under the conditions you describe. Easiest way to tell is to locate it near the tensioner and apply pressure to it. if the rattle stops when you apply pressure. you've found your problem and the shocker needs replacing.


good luck.

 

Thanks for the suggestion Merctech but like I said it does it even with the belt off so I don't think that would be it.