Alternator pulley noisy

[Josh mcleod]

I'm trying to diagnose a noisy belt. At first I thought it was likely a idler pulley or the tensioner. Although neither run perfectly smooth, it's the alternator pulley that's making the squeaking noise. I've called a few parts place (in canada) but I'm told it's not a "wear part" and I can't replace just the pulley. Do I need to replace the whole alternator?

 

[Mark Keefer]

Go to a junkyard if you want just the pulley

 

[EddieS'04]

Are you sure it is not the altenator bearings. Never heard of the pulley making the noise.

 

[Yardsale]

Agree - pulleys don't make noise; bearings and bushings do.

 

[Josh mcleod]

I'm gonna start by changing the tensioner and idler pulleys. If I'm still hearing noise I'll replace the alternator. 2005 87,000 km

 

[Yardsale]

If it were me, I'd first remove the belt and hand spin the parts. If I couldn't determine which is bad, then, I'd spray the idler and tensioner pulleys with something like WD-40, one at a time, to try to locate the offending part.



Another thing you might try is using a mechanics stethoscope to locate the noise. A homemade and fairly effective version can be made with a piece of garden hose and a screwdriver (or only a screwdriver). You could even put a funnel on the ear side.

 

[Igor Smetaniuk]

I've been use a 3ft. piece of 3/8 rubber hose for years and it's always helped me pinpoint hard to find noises. Fits tight enough to the ear. When I find the culprit I always think of it as getting hosed twice - once to find the noise and once to pay an enormous amount $$$'s to the dealer parts dept.



I had replaced my original alternator with a NEW NAPA unit (not reman) - so they claimed. Within a month a started hearing a strange noise from the front of the vehicle. It would come and go until it progressively got worse. I finally got my hose to the ear and sure enough it was a bearing. Took it back to NAPA for a warranty replacement and the new NEW one solved the noise issue.



I agree, how can a solid piece of steel that's mounted on a shaft without it's own bearing make noise?

 

[Josh mcleod]

Ok I think I've solved my problem. I replaced both the tensioner and the idler pulleys as well as the belt. I no longer hear any noise. Thanks for he responses.



I find it strange that the alternator squels pretty loud when I turn it by hand. Obviously there is no noise while under load. Btw I used a napa oem size belt.

 

[Yardsale]

Which part was bad?

 

[Josh mcleod]

Honestly, I really couldn't tell. I think it was the idler pulley. After removing and inspecting both the idler and tensioner pulleys I couldn't really find a problem.