Originally Posted by SkylineR35GTRx

You know, my buddy with an E36 M3 had that noise too, it was a pretty loud whine that sounded like a super charger. It turned out to be a faulty alternator. How long has this been going on? I thikn maybe the alternator is not putting enough power to recharge the car fully, but sitll charging so that your radio might be affected? To check just take off the belts from the alternator pulley and spin it, see if u hear that wind. On the bimmerforums.net, they said thats how you can check, but when we did it, we didn't hear the whine but took it to kragen's for them to check and they said yeah it's gone. I thikn other causes could be tensioner pulley or power steering pump.

http://forums.bimmerforums.com/forum...lternator+test

Originally Posted by sti4j0n

re: supercharger noise: did u do a FMIC ? SAME thing happened to me when I did my fmic, it sounded like a busta a$$ supercharger.. i found out that the coupler coming off my turbo wasn't fastened enough, so i tightened it up to the best i could, and it went away and held boost 99.7999repeating%. I'd check all the connections from ur intercooler to ur turbo and also ur tb. hope this helps ya