Remanned Alternator Whine

[nick0789]

2005 tahoe
Replaced alternator with a reman unit from NAPA earlier this year under warranty

I got out of the tahoe to check the mail and heard this whining sound and wasn’t sure if this is cause for concern or if it’s “normal” in remanned units. I figured it shouldn’t make any noise but just wanted to confirm. I used a stethoscope and it was definitely louder on the alternator than the PS pump but I also heard it pretty clearly there as well.

Assuming I need to replace it I’m going to bypass the warranty process and order a new unit from RockAuto — are there preferred brands other than ACDelco or do I just bite the bullet with an OEM part?

 

[OR VietVet]

You can really pin-point it by hearing it and unplugging the alternator, while running, and if noise stops, it is the alternator. In my Garage section thread, I had a 2010 Camry I was working on and had the same noise. I unplugged it and noise went away. Plugged back in and noise came back. Replaced it. Problem solved. Still with AC Delco or Genuine GM parts. When you look at RA for alternator, there are a couple of choices. Verify correct application and order as needed.

 

[mountie]

I needed to replace my alternator a couple months ago. I had a short time of opportunity at my mechanic's shop, after he tested it. He got a new, ( not a reman), from Autozone. Works good & a lifetime warranty.

 

[rockola1971]

That sounds like a noisy needle bearing which is what support the rear shaft of the rotor.