Whining noise

[maxmk8]

I have a 92 325is. The noise sounds a lot like alternator whine, but the voltage seems ok and no other electrical problems persist. It goes higher pitched with higher RPMs. I have heard that a defective dong (door chime etc) may set of a very similar noise, is there a way to disconnect it?

It is not coming from the stereo speakers. Since turning them on and off does not alter the noise. It seems like with the headlights on the noise is a bit louder. Which in return would suggest alternator whine again used: .

The alternator has a rebuild sticker on it so I know it is not original.

Any tips?

[maxmk8]

Well to clarify, I just noticed that I am getting the noise through the stereo as well. It amplifies it about 40%.

[///M Power]

Supercharger.


Do you have an aftermarket stereo system? Possibly a AMP.

[maxmk8]

lol I wish. Car's stereo is "stock". Except for the rear speaker that I replaced. Made no difference in noise etc.

[Gator]

It sounds like your alternator belt is slipping. When you turn on the lights, you are putting more load on the alternator which causes the belt to slip more and therefore the noise increases. It could also be a bearing in the alternator or tensioning system but in that case it is unlikely that the noise would change when the lights were turned on.

[maxmk8]

Thanks for the reply. The belt was actually off by 1 tooth on the power steering pulley. But the ongoing alternator noise is very slight. It is significantly louder (since it is coming out of the speakers) with the stereo on and "volume all the way down" so I think I may run an additional ground and see if that will make the problem better.

[thooper41]

might be the same noise my car makes. bought the car 2 years ago and from the day i bought it till now 3k-redline 1st gear and about 4k-redline in 2nd gear 3rd-5th and N no noise. sound could pass for a supercharger and i kinda like it so as long as its not hurting anything i wont mess with it.