Diablo_CLS55

I’m hearing a loud noise coming from the front of the engine on my CLS55. Car only has 60,600 miles. Doesn’t sound internal to the engine. Doesn’t sound like its anything from the valvetrain. Anyone know what it could be? I rarely drive the car hard and do mostly highway driving. Oil level is fine and oil temp seems to be normal. Car still pulls like normal. Sounds like it’s coming from the pulley.

Link to a video of the problem I’m having:

https://youtube.com/shorts/Evxfl0NPotY?feature=share

UncleBenz55

I think you answered your own question

nd-photo.nl

I think so too While you are in there:

-Replace the supercharger idler pulley



-Replace the supercharger pulley bearing



-Replace the supercharger oil (Mobil 1 Jet oil)



It could also be the other bearings (from the serpentine belt route)

machild

While you may be correct that it is a pulley, it is easy to use a section of heater hose to act as a stethoscope. One end to your ear and the other end moved around the area you think the noise is coming from. When the hose comes across the noise you will hear it clearly through the hose end. No guessing.

nd-photo.nl

I love this ghetto lifehack

machild

Here is another option for pulleys and the bearings: https://mbworld.org/forums/w211-amg/...er-pulley.html

kevm14

I've had good luck with my cheap Harbor Freight automotive stethoscope.

Diablo_CLS55

I think I’m gonna upgrade the pulley to a smaller one while I’m in there

nd-photo.nl

Even better

CQHall

I heard that sound. 45 minutes later, my supercharger and accessory belts where in shreds creating havoc in the engine bay.

You should be able to take the tension off of the belts and remove them from one pulley in the system, then wiggle the pulleys to see if there's play.

Here are two threads regarding my adventure:

• https://mbworld.org/forums/w211-amg/...d-replace.html
• https://mbworld.org/forums/w211-amg/...ulley-set.html

Diablo_CLS55

While checking fluids on my car today, I looked very closely and saw the bearing is shot. Don’t know why I waited till now to investigate but is this an easy job to replace just the bearing or do I need a whole new assembly?