190E 1992 metal rattlening noise front engine
 

There is a loud rattlening noise that becomes audible just over the idle, at about 800 rpm, at the front left side of the engine.
Could it be the distribution chain and guides, or is it possible that the alternator bearings could make that much noise too?
When using a hose as a stetoscope, the noise is most marked on top of the alternator. There is no noise on the valve cover other than normal valve clicking as far as I can tell.
THKS!

rattle !
 

It could be the engine/shock absorber bush, I had the similar problem !!

1903e ratteling noise front right engine where alternator located
 

A stetoscope revealed the highest noise on the body of the alernator. No unusual noise on valve cover or or timing chain cover. Could it be that this is just alternator bearing(s) worn out and if so, how could I test for that? Remove and inspect it or is there another way?
THKS

noise appears to come from alternator? + aux.cool.fan?
 

I took alternator off and found play in the bearings and decided to rebuild, basically replacing the bearings, the other parts look ok.
The aux. fan is also very noisy, but this may be normal on these models? Right?