2.4 New Belt Squeak / Squeal

Flyer58

YJ Enthusiast
Joined
Apr 12, 2020
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Location
Magnolia, Texas
I recently installed a new harmonic damper and a new serpentine belt because the old belt was squealing for a few seconds after startup and had a few cracks in the ribs.

So I tightened the new belt to what I thought was about right and it started squealing the entire time from idle to 4000 rpm. I gradually loosened the belt so the squealing mostly stopped but that created the old problem of squealing during start. Now it's adjusted so it doesn't squeal on start but still has a minimal squeal when running. There's no happy place right in the middle.

No AC to test and when using a stethoscope on the alternator, idler pully, water pump, and power steering pump, they all sound ok.

I can't seem to pinpoint the high pitch chirp/squeal but it sound closer to the power steering pump side than the alternator.

The power steering works well with no grinding sounds, alternator puts out 14 volts, no water pump leaks.

I'm at a loss after several hours of troubleshooting. Definitely RPM related.

Any guesses?

See if this video link works

 
I recently installed a new harmonic damper and a new serpentine belt because the old belt was squealing for a few seconds after startup and had a few cracks in the ribs.

So I tightened the new belt to what I thought was about right and it started squealing the entire time from idle to 4000 rpm. I gradually loosened the belt so the squealing mostly stopped but that created the old problem of squealing during start. Now it's adjusted so it doesn't squeal on start but still has a minimal squeal when running. There's no happy place right in the middle.

No AC to test and when using a stethoscope on the alternator, idler pully, water pump, and power steering pump, they all sound ok.

I can't seem to pinpoint the high pitch chirp/squeal but it sound closer to the power steering pump side than the alternator.

The power steering works well with no grinding sounds, alternator puts out 14 volts, no water pump leaks.

I'm at a loss after several hours of troubleshooting. Definitely RPM related.

Any guesses?

See if this video link works

View attachment 120982
May have one of those not rotating as free as it should, water pump, alternator, ac comp., or ideler pulley . I personally would try spraying a little belt dressing on the belt as it runs.
 
May have one of those not rotating as free as it should, water pump, alternator, ac comp., or ideler pulley . I personally would try spraying a little belt dressing on the belt as it runs.
FOR ME…I had a 1986 IROC-Z Camaro that had squeaky belts. I put belt dressing on it and it squeaked worse. I use a bar of soap. A quick tap with the soap and done…for me. Used it on every car I hav had. Just my .02
 
Thanks, I'll dig a little deeper and try a few more things.

Something I came across is the PS pump has a plastic pully which can crack and cause squealing. Dorman has a steel replacement for $16 so that may be a cheap fix as some reviews say it stopped the noises. I also have a can of belt dressing and soap to try.

All accessory pullies spin freely by hand and without noise. Starting the engine briefly without the belt is quiet. If only there was a way to test each one individually pully with tension on the belt. I did find a video where a guy tried using tie wraps as an emergency belt and it worked LOL,

I did try the old belt which only chirped/squealed when starting and it screamed louder than ever the entire time.

Maybe I should have bought the $200 belt and not the $20 belt.

Thanks for the help, I'll report back.
 
OK I made a little progress, possibly. I tried belt dressing and while it helped with the start up squeal it did nothing after tightening the belt.

I also tried putting a load on the alternator by turning on all the lights and fan - no change. The loaded up the PS pump by turning the steering wheel to the stops and again no change.

Next step was to try and isolate each accessory. First I simply removed the idler pully to eliminate it and no change.

Here's where it gets stupid, don't try this at home, entertainment purposes only, learn from what I did. No animals were hurt during this test.

I tried the tie wrap trick using some 2ft plastic tie wraps a neighbor gave me years ago and have no other use for. I ran each pully individually, water pump, alternator, and power steering. Low and behold the power steering pump squealed.

Like I said the pump works well, functions properly without any internal noises you normally hear when they go bad. Just belt noise.

I'll try the Dorman steel pully next.

For LOL's and yes I know the water pump is turning the wrong way but only for a few seconds.

Cheers.

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A pair of pantyhose will also make an emergency belt. Just don’t try and run too many accessories, my friends and I usually left out the power steering pump and it worked ok.
 
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Problem solved

The Dorman pully arrived today and with the help of an Auto Zone free loaner tool I removed the old plastic pully and replaced it with the new steel one. One other benefit of the Dorman steel pully is it has three holes in it which will line up with the PS pump mounting bolts.

Easy process, made as sure as I could the pullies were aligned, installed and tightened the new belt and gave it a try.

The first start gave a short squeal at start and quiet after. I gave one more rotation of the bolt to tighten the belt and the next start was quiet as well as all RPM's up to 4000.

Looking at the original plastic pully I found a small chip on the outer edge and some deterioration around the center steel bushing. The pump and hoses look new so the previous owner might have changed them.

I'll give it a longer test drive tomorrow and see what happens when it warms up.

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