Damn alternator noise.

[Jean]

So, a few months ago I bought a replacement good alternator from a recycler (bavarian) because the alternator that came with the car made nasty noises if you bleep the gas or downshift.... Now it started doing exact same thing, keep in mind belt, the alternator adjustment nut and bracket are new. Half the time when I start the car after it's been sitting for a bit and if I bleep the throttle it would make make noises.

So, it's either going bad or possibly the belt tension is too lose or tight.

What would make the noise worse a belt that's too tight or too loose ?

[Mike325]

A belt that is too loose would make like a skidding tire noise. A belt that is too tight will put extra strain on the alt bearings. This could be the problem you are having.

[Jean]

I checked the belt for wear marks and didn't notice any, maybe it's the alt. bearings like you said ..

[mikeedler]

you wont see wear marks. It just slides on the pully. best "back yard way to check the tension is to grab the belt, twist it, it should only twist about a 1/4 turn.

if its the bearings, you need to loosen the belt, cause your destroying the alt.

[Jean]

Replaced the alternator, noise is gone. I'll check the tension again today once a new alt. bracket arrives . Thanks for the tip on checking the tension by twisiting the belt !