Thread: Alternator (maybe???) bearing whine

Pop the belt off & see if the noise is still there. It's safe to run the engine for a few seconds without the belt.
If it's not, spin each pulley & feel if one's a bit rough.

Originally Posted by Scouse

Pop the belt off & see if the noise is still there. It's safe to run the engine for a few seconds without the belt.
If it's not, spin each pulley & feel if one's a bit rough.

Cheers.

I'm assuming the only thing that stops you running it for longer is the water pump, so temperature yes?

Power steering and alternator won't matter unless the battery goes flat after a few hours huh

I replaced a few of my pulley and changed the ac compressor clutch bearing looking for a noise. Turned out to be the small plastic idler pulley under the tensioner pulley ( not the idler pulley) . Problem taking the belt off the noise was only there under load. I did put a post on about this pulley as mine had worn thin to what I think is a dangerous state, ready to explode with no doubt messy consequences
As a side note I just bought a new serpentine belt from Supercheap for my new car. $43 which I thought was pretty good, Repco wanted $200

Originally Posted by Pete38

I'm assuming the only thing that stops you running it for longer is the water pump, so temperature yes?

Yes.
PAS is usually only noisy when it's actually operating.

Hi

I agree it could be any of the bearings on the various pulleys which are involved

There was a factory recall for the tensioner pulley on the Thor engines, I replaced mine with a Nuline EP027.

Maybe take the belt off and spin each pulley by hand and see if it feels rough or loose in any way.

One of my other pulleys was slightly eccentric and could be seen when the motor is running.

Any wear or slop in any of these pulleys is going to wear out your water pump bearing faster than normal

Steve

Thanks Scott, Wayne and Steve. All good points, and taken onboard. I'll start the diagnostics before the end of the weekend as I don't plan to be driving very far till then.

There was a TSB released about 1999 or 2000 referring to the whining noise and it was recommended the bearing in the LH idler pulley be replaced with a metal one of 80mm diameter instead of the original plastic 70mm one. A slightly longer serpentine belt (2335mm vs 2325mm for the 70mm pulley) to compensate was specified as part of a kit. Apparently the LH idler was subject to significant forces and belt speeds, hence the whining, so they specified a (steel) pulley of larger diameter (to reduce the rpm) .

I know this because since I ceased consuming alcohol I have a much reduced social life and read a lot

Originally Posted by wayneg

As a side note I just bought a new serpentine belt from Supercheap for my new car. $43 which I thought was pretty good, Repco wanted $200

Can you tell us the part no. Wayne?

TIA

Steve