Noisy Alternator
 

My alternator has developed a faily loud whine which is always the same and constant, hot cold fast or slow. It goes up and down with the engines rpm's. It is still charging just fine though. It looks like my power steering pump is leaking a tiny bit. Could a little power steering fluid have damaged the alternator? Do you think that the whining indicates bad bearings? Could it at some time seize up, or cause enough resistance to damage the belt? Thank you for your help!

RE: Noisy Alternator
 

PS fluid definately kills alternators!!! It could be the bearings, but it's more likely the brushes. I haven't seen an alt. seize, but I guess anything is possible. I'd expect that it won't be charging very well within the month.

RE: Noisy Alternator
 

Sounds like it is going out to me too. Did P/S fluid get on it?

RE: Noisy Alternator
 

how about the belt? is it cracked? maybe its loose , and that's the source of the noise?, cuz it would suck if your alt did get damanged from the power steering fluid...yikes

RE: Noisy Alternator
 

I always thought a whining alternator means one or more diodes (in the rectifier bridge) are going bad. It might be supplying enough current to keep your battery charged. You'll see a funny waveform if you look at the alternator output with an oscilloscope.

That shouldn't be caused by a little PS fluid, but ???

RE: Noisy Alternator
 

Is that where the whine comes from?!? I always thought it was the brushes, but both parts get replaced anyway.

RE: Noisy Alternator
 

If you simply buy & installa new brush set,it doesn't include the rectifier bridge.

Brushes just make a kind of swishing sound, same thing you can hear when you spin the alternator by hand.

But... noises are really funny things to describe in text.

RE: Noisy Alternator
 

When I rebuilt the alt on my Z24, the kit had both ..... I guess there are both kinds of kits .... or the Chevy kits are different.

RE: Noisy Alternator
 

Try increasing the tension on the belt or just replace it. My power steering pump recently blew the pressure fitting and sprayed PS fluid everywhere and saturated the alt. Sprayed it with brake cleaner + new belt and the whine was gone. Alt still charges great too.

RE: Noisy Alternator
 

yeah, a kit usually comes with both in my experiences... but i also prefer just to get a rebuilt one to now have to worry about it... and there's generally a warranty on them as well...

but yeah, start doing research on a replacement or kits cuz you WILL need one if it's not a belt making the noise..