Brian B

I just changed my accessory belts and started the car up tonight. I now have a sound from (I think) my alternator. It sounds like something is "tinging" off the alternator fan blades (it sort of sounds like the sound of the monkee doll that bangs the cymbals). When I looked, I can't see anything hitting the cooling fan or loose that might be rattling. Could it be the bearings or the diodes inside of the alternator now that the V belt is properly tensioned? When I put the belts on, I made sure not to overtighten them. If anything, they are slightly looser than the manual suggests.

I put a Bosch alternator in the car about 5 years ago. It seems to be working well as my battery stays charged and my volt meter stays steady. I'm just worried that it may be self-destructing...

What is the life span of one of these Bosch rebuilds?

Any ideas?

Mrmerlin

is it possible that you could have bent one of the cooling fins on the alt? I would remove the belts one at a time till the noise goes away then figure out whats causing the noise. Usually Alt bearings last a long time unless they get wet then they rust and seize

Garth S

Check the alt. shaft nut that compresses the pulley, fan, and spacer onto the front bearing inner race. Rarely are they loose, but if so, would allow the fan to wobble on the shaft: the pulley is normally positioned by a woodruff key, so would still operate correctly were the nut loose.

Brian B

Thanks for the suggestions, guys. I'm going to pull off the belt tonight and see what's going on. I was thinking about it today and I remember hearing the noise in the recent past before I did the belts. With the new belt on and tightened, its really pretty loud.

I just don't want to be out with the car and have the alternator decide to self-destruct.