KillerBee

My 2004 diesel Ram developed an intermitted squeal recently that has progressively turned into to a constant noise.

I removed the serpentine belt and did some investigating today.

About 4 months ago I noticed my waterpump had a slight leak so with winter coming I decided to replaced the water pump, the pulley on the tensioner, the top idler pulley, the serpentine belt and coolant.

Everything ran and sounded good until recently.

When I pulled the belt today all the pulleys were tight and spun great....alternator, power steering, fan bearing, and AC compressor.

The sound is gone with a quick run of the engine without the belt.

The new belt (Gates HD green) looked great and showed no signs of abnormal wear.

I pulled the tensioner and everything also looked and felt great.
I'm fairly confident there isn't a problem with any of these items.

The water pump turned but had a slight resistance and made a very faint squeking noise, nothing grinding or wobbly, kinda sounded like a tight rubber O ring.
When spun the pump didn't spin continuously, maybe 1/8 turn.
The rest of the pulleys would spin multiple revolutions.

I cleaned up the belt and put everything together and took it for a 5 mile run and everything stayed quiet.

So how freely and how long should the water pump turn when spun?

The truck runs cool and has no cooling issues.
The pumps are easy to replace but I would rather not mess with it if the resistance and lack of spinning is normal.

Thanks.

Checkmate

shouldnt spin long at all since the water will give it resistance.

KillerBee

Thanks for the info.

I really didn't think the water pump was bad but I wanted to be sure.

I drove the truck today with no issues or squealing.

I've read that the the belt can sometimes get a glaze build up on it.
The new belt I put on (green Gates HD) did look a little slick with some buildup on the backside.

I put the old factory belt back on for now to see if the noise comes back or not.
I'll clean and degrease the Gates and put it back on later but I have a feeling that is the cause of my noise.

Mexstan

A couple of years ago I had the same problem. Replaced the tensioner, dismantled the alternator, installed a new water pump, but nothing stopped the squeal. One band of the belt kept on peeling off as well. A shot of belt lube would stop it for a while. Checked the alignment, and everything checked out. With one band of the belt gone, the squeal disappeared too, which brought me back to alignment. Finally I gave up and ran the thing with one band missing. It's been like that for about 2 years now and no further problems. Keep a spare belt in the truck in case I need it on the road.