OK, I recently installed stage 2 kit on my car, now i have had for a few weeks now, one night I hear this sould like a Buzzing/ Bag of marbles at around 1800-2000 RPM range, it doesnt have that Whine that it use to have as I slowly brought it up, now the whine only occurs at Real high RPMs, so i popped the hood it seems that the noise is coming from the supercharger. my second question is what could it be thats wrong with it if it's the blower?

 

i think i have the same noise. is it just at idle only til about 2000 rpms if so i have the same noise. and did you install the stage 2 yourself? i did. i took my time and didnt forget anything i noticed the sound right after the install. but i also noticed that it did not affect my boost or anything, which i thought it might. my car runs great! im hitting 15psi. i wouldnt worry about it until it gets louder, or you notice a loss in power. my opinion. i did however save all of my stock parts and if something was to happen, i'll just change it back to stock and take it to a dealer. i had tons of ppl(car guys) listen to the noise and everyone says that they dont know what it could be but that its not a bearing sound.... i would say just drive it some more til it gets louder.

 

https://www.cobaltss.net/forums/problems-service-maintenance-69/help-weird-noise-41135/