elodesignco

what started with a whine, then failed vacuum pump, is now presented as a random rough idle.

the whine came and was rev dependent. it has since stopped. at one point with revs held at 2500 it sounded like a clutch bearing of sorts engaging/disengaging.


I now have an idle issue that sounds like the engine is going to fall out of the car.


I cleaned the intake manifold yesterday and it's idling better in general but still get this occasional, random rough idle.

while cleaning the intake I did notice some oil in the turbo pipe. but very little beyond the intake manifold.

any ideas? could it be multiple separate issues?

NZ-Merc

Hi
I think in the second video the noise is related to a seized sprag clutch bearing which is part of the alternator pulley.
I have recently diagnosed my 2008 c200k with same noise at idle, (rattly sound) and when it is playing up and making the noise the fan belt tensioner is very rapidly flapping back and forth.

There are various videos on tube with how to diagnose if the one way clutch has failed they all require the tension to be removed from the fan belt.

I brought the new pulley from eBay and are awaiting the remover too to arrive before I swap mine over.


The first video just sounded like normal alternator operation.