Alternator Whine

[Brian]

I seem to have developed an alternator whine on my 1996 325i.
It is not constant but is annoying.
Is there anything I can do about this or must it be replaced?

[Dudesky]

Unless your electrical system is getting weak, your alternator is fine. Alternator whine is caused by a ground loop, meaning one of your stereo's ground wires has come loose somewhere. Because of that, the current is redirecting through your stereo system and on to another more secure ground point, causing the whine; it's taking the path of least resistance. You need to locate that loose or disconnected ground point and fix it.

[Brian]

Thanks a lot for that - I will check for this

[xsperf]

is it a whine through your speakers or from the engine compartment? at first i thought it was your serpentine belts

[mullethunter3]

Wow. Good luck finding that ground wire. It took me two years to find mine.

[Exilion]

Actually if you have an after market stereo I'd guess it's right behind the head unit. Sometimes it's like a bad solder job or no solder job... (I never soldered my stereo in because I know I'm going to replace it eventually... worked ok for awhile but now the whine is back)

[Brian]

The whine is from the engine - thanks Mullethunter3, I hope I find mine sooner - the noise is driving me crazy

[SHAHAB323IS]

Originally Posted by Brian

The whine is from the engine - thanks Mullethunter3, I hope I find mine sooner - the noise is driving me crazy

if it's coming from your engine couldn't it be the alternator pulley?

[lowkeyneon]

Originally Posted by Brian

The whine is from the engine - thanks Mullethunter3, I hope I find mine sooner - the noise is driving me crazy

the bearings in your pulley of the altenator are going bad, and its not going to go away, just one day it will seize up and it wont be good. Its happend to me before. Somehow either the cap to the bearings came off or water got into it and made them go bad either way thats 99% chance what it is