Video: Drive Belt Squeal Diagnosis
#1
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Year: 2000
Model: Cherokee
Engine: 4.0L I6 Power Tech Engine
Video: Drive Belt Squeal Diagnosis
Hey jeepers
I recently changed my serpentine/drive belt in hope of solving the A/C squeal on a cold start. I replaced the old one with a gatorback belt.
My problem only occurs on a cold start when I turn the a/c on. The higher the RPM's at start (revving) the more it squeals. Also it seems to happen only at higher speeds of the fan. So if i start it in speed 1 no squeal happens. I ramp it up to 4 and it starts to chirp. It goes away after it gets a bit warmer. Take a look at the video I just took.
You can see the belt start to slow down and make the squeals once I turn the fan speed up to 4. Even more once I rev the engine a bit. Goes away once I turn the a/c off.
What could this be? Is this the idler pulley (doubt it, but hope so since it's cheap) or the a/c clutch? The old belt was pretty loose and squealed the whole time like I when I rev it now until it warmed up.
I recently changed my serpentine/drive belt in hope of solving the A/C squeal on a cold start. I replaced the old one with a gatorback belt.
My problem only occurs on a cold start when I turn the a/c on. The higher the RPM's at start (revving) the more it squeals. Also it seems to happen only at higher speeds of the fan. So if i start it in speed 1 no squeal happens. I ramp it up to 4 and it starts to chirp. It goes away after it gets a bit warmer. Take a look at the video I just took.
You can see the belt start to slow down and make the squeals once I turn the fan speed up to 4. Even more once I rev the engine a bit. Goes away once I turn the a/c off.
What could this be? Is this the idler pulley (doubt it, but hope so since it's cheap) or the a/c clutch? The old belt was pretty loose and squealed the whole time like I when I rev it now until it warmed up.
#4
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Year: 1985
Model: Cherokee
Engine: 2.5L
On my 85 2.5L I had a bad squeal and the tighter I got the belt the more it would squeal, chirp and squeek. Finally got it really tight and it started throwing belts. I finally got to looking at it and noticed the alternator wasn't aligned with the rest of the pulleys. Seems the bolt that held the alt in place was in the wrong hole and the more I tightened the belt the more it would torque the alt sideways. Put the bolt in the correct hole and got the belt just tight enough and it has been quiet ever since. Not sure on the routing of the newer engines, but be sure something hasn't pulled one of the pulleys out of alignment.
#5
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Year: 2000
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I'll do a visual inspection. I don't want to take out all the stuff to get back in there. At least it'll be easier the second time around..
#6
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Year: 1999
Model: Cherokee
Engine: 4.0 I6
Originally Posted by JeepCherokeeSport00
How did you figure out it was your alternator?
#7
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Year: 1996
Model: Cherokee
Engine: 4.0L Straight 6
While it's running, see if you can see any wobbling in any pulley. Also, take the belt off, and go through the pulleys and see if there's any play. Spin them around if possible and pray you hear one that doesn't sound good.
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#8
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Year: 2000
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#10
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Year: 1999
Model: Cherokee
Engine: 4.0 I6
Originally Posted by SlickXJ
Just now watching the video, almost certainly the clutch. Take the belt off and feel the bearing and see if it feels gritty or has play.
#11
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Year: 1999
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Oh and OP, even though mine ended up being my alternator I could control the squeak with the AC controls as well. If I had my air turned off if rarely would squeak. Just because it squeaks with air on doesn't mean it's the AC clutch.(it could be the AC clutch just as easily though)
#13
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Year: 1996
Model: Cherokee
Engine: 4.0L Straight 6
Another trick my dad taught me is to take some like half inch rubber line or something similar, put it up to my ear, and point it at each bearing, as close as I could. I believe the same thing can be done with a screw driver, but the screw driver has to be touching and on a moving part, it's not feasible. That's why the screwdriver method is saved for stuff like an engine knock or the like.
#14
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Year: 1996
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Engine: 4.0L Straight 6
I believe there's also a water test. I'm not sure, but I think you spray water on the pulleys and if the squeal goes away, it's a misaligned pulley, and if it stays, it's a bad bearing. Again, not sure, but might be worth looking into.
#15
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Leave your A/C off and turn on headlights and rear defrost and any other electrical items. If it starts to squeal as you add load to the alternator, then you have your answer.