Ever since I had my crank underdrive pully installed my alternator has moaned. It has about 30-40K miles on it and is a stock GM part. Is it going out or does it moan because of the underdive pully? It is loud and very annoying.

Thanks again guys...

 

It's hard to say if it's the alternator, or something else. Try taking the belt off and turning the alternator pulley by hand. Does it make noise then? How about the "play" in the pulley (i.e. bearings), is it loose?

You could also check the idler pulley, AC compressor, and the rest of the pulleys for looseness or anything else suspicious while you have the belt off.

Is everything aligned, are all of the pulleys in-line with each other?

When you start the engine with the belt connected, does the noise definitely come from the alternator, or just from somewhere in the fron of the engine?

If you have a factory alternator with only 40K miles on it, I would think it is something else. My original alternator lasted about 150K.

 

Have you pinpointed the noise specifically to the alternator? As mentioned in the above post, there could be several factors that lead to the noise that you are now experiencing. Personally, I haven't seen an alternator go bad with only 40K on it either, but that doesn't mean it still isn't a possibility.

 

The shop and I determined it is most likely the altenator. He let me listen to it with a "crow" bar like tool on the altenator and the other end in my next to my ear. It sure sounded like the altenator. Until I had the engine fixed I thought it was my power steering pump. Just another weird problem with my car...

I just got it back Friday. I am starting to think it is running warm too. The fans seem to be on all the time and it is pushing 190F even with my 165F thermo. See my other thread for another weird problem:

http://web.camaross.com/forums/showthread.php?t=524512

Thanks,

Chris

 

Get yourself a cheap automotive stethoscope. I found one at Sears for about ten bucks.

 

i would say that it isn't too abnormal being as how your alternator is now spinning slower and having to work harder to supply the same voltage/current to keep the battery charged

how does your voltage guage look when its idling with the fans on? have you stuck a voltmeter on the battery to see exactly what the voltage you are running when idling

 

If your fans are constanly on, and have not been manually made to do so, then you need to scan your PCM for trouble codes. If your CEL isn't on, then it's a silent code.

190 degrees is not a big deal, that's normal