Does a loud supercharger pulley have to be replaced?




The supercharger pulley bearing was indeed shot. You can see the wear/burn marks in the last picture below. It was replaced with the NSK bearing purchased via ebay and the link above.
This substantially reduced the noise, but there were other issues. The grooved idler pulley was also making alot of noise so, as that is a cheap part readily available from the dealer, the mechanic also changed that. The smooth idler pulley was dry so the grease was repacked. Then, in the course of all of the testing, the check engine light went on, the car went into limp mode and a faulty accelerator pedal was replaced! Never a dull moment.
So, as the before and after videos show, the car does sound better. More importantly, now my mechanic feels that remaining noise is just annoying - not something that's going to cause bits to start spraying around the engine. He feels the remaining noise is attributable to the supercharger clutch flex plate.
Thank you all for your helpful advice in getting right to the bad bearing diagnosis. Saved me lots of time, hassle and money. Dinner and drinks on me next time you are in the Bay Area (ok, ok, feel free to insert your favorite SF-bashing joke here)!

Before:
http://www.youtube.com/watch?v=vcRBCYfIw9E
After:
http://www.youtube.com/watch?v=QPEHIo-AR8o




Slightly OT - it still sounds like you have a bit of a knocking sound. Is that just reverb from the garage? Mine has the same sort of tune to it, on top of the screeching.
Well first thing, I am new here. I just aquired a 2002 C32 from a used car lot here in Denver. 101,000 mi, and all the service records from 500 mi to 97,000 mi. 10 scheduled oil changes, 2 coolant flushes, 1 factory O.E.M. I/C pump R/R @ 70k, 1 transmission service @ 70k, and 1 power steering system flush at 70K. All performed by Mercedes of Littleton, CO. Mint front to back. Paid 11k, good deal?
The only issue I have is the bearing in the charger pulley is going, and I must say this site is most useful to help from spending $1400 on parts from the dealer. LoL.
What I have found in my research with, your forum, NSK Americas, Mercedes, and Local NSK Distributors. The bearing stated earlier in the thread NSK 32db45dum, in fact has a different NSK #. The # you have listed is the # Mercedes has stamped on the bearing for there manufacturing and parts support identification. If you call NSK Americas # 1-888-446-5675, and get to an operator. You can give them your state and closest major city, and they will give you a local distributor. When I called the local NSK distributor and gave them the # they had to call NSK because the # wasn't in there database. The number that NSK superseeded to was this NSK-32BD45A1T12DDUCG21. BEST OF ALL it only cost me $27 delivered and its even the right junk.

Wanted to share this to save everyone a few bucks.
...help a brother out.
The Best of Mercedes & AMG
Running nice and quiet now.






