Alexb1

alrighty, so bought my 320 with 156k for 700. but ive obviously have had some issues arise. one most notibly is i have a sound coming from the front of the engine kinda sounds like the idler pully has lost tension, but it hasnt. full accesory drive system has been replaced by a mercedes dealer a week before i purchased. it only happens when i start it while in the morning. ive been thinking maybe the chain tensioner? if i get a chance to i will record a vid. i have not noticed a issue with the driving.

alecmascot

Alternator pulley......

tjts1

C320 has a solid alternator pulley, no OAP. I would remove the belt and spin each pulley by hand.

Alexb1

Yeah ive taken the belt off and checked all pulleys. alt, and idler are brand new. i feel like it could be the chain tensioner, if i replaced that would that cause the chain to get off time? or any adverse effect?

alecmascot

Run the engine for a short while with the belt off and see in the noise it still there.