foreverflykellz

cyber

Sounds like pulleys at the engine compartment. I'd open the hood and listen if it is coming from there.

Serndipity

Sounds like a really bad bearing, close to completely failing.

Since it's occurring at idle, I would check the serpentine belt pulleys a.s.a.p.!

Very easy to diagnose and repair on your M112 engine.

See posts # 7, 12 and 14 at:

https://mbworld.org/forums/clk-class...tensioner.html

jonUF02

Listen for noise at front of the engine, look for jumpy or wobbly belt. Remove the serpentine belt and spin each pulley; idler, tensioner, alternator, water pump. Feel for anything that does not turn smoothly, makes noise, or wobbles, replace that part (hopefully not the water pump, because that is the only hard one). If you have the belt off, might as well replace it, and if you're doing that, then go ahead and replace the plastic idler pulley that will break eventually, and the belt tensioner because it's important, fairly cheap, and easy to replace.

foreverflykellz

thank you both for your responses, I look into the bearing as well as check the belt and all the his weekend