Alternator Noise
 

My car is pretty noisy at idle, so I took the belt access panel off to listen. One thing I noticed is if I rev the engine up a bit, and let off the gas, there is a screaming noise.

Using a rubber hose to listen, I've isolated it to the alternator - specifically the plastic hub/pulley assembly. Listening with the hose while the engine is idling, it makes a lot of clicking/tapping noises. Then revving it, it sounds almost like it's spinning faster than the alternator itself and slipping. Hard to tell.

I don't know the age of the polyrib belt. I am going to order one and replace it, but I'm wondering if I need to buy new parts for (or refurb) the alternator?

Thanks!

-james

you said you took off the panel. so you are able to see the actual engine right?

it should be pretty easy to isolate the sound at that point. the noise is usually from the belt being misaligned. check the idler pulley to make sure it isn't loose and the the belt isn't rubbing on the plastic cover at the top where the cables run through.

Yes, I can see the engine, and was using the rubber-hose-to-the-ear trick to listen to each pulley on it's own. The idlers/tensioners sound healthy to me, and nothing appears to be loose. I will get a better feel for the bearings when I replace the belt, but I haven't ordered it yet.

The alternator is the main pulley making noise. I think the rest of my idle noise may be a heat shield or exhaust issue - but I want to take care of any alternator or pulley problems first.

No one else got an opinion? :(