Belt squeals when AC is on.

[AnthonyZ28]

So whenever the engine is cold and I run the AC the front end squeals really loud, probably the belt but im not sure. However when I cut the AC completely off, the squealing stops. After running for a couple minutes it stops. What can I do to stop this? 93' XJ with 4.0 I6.

 

[DansGreyMj]

Its just the belt slipping from the extra load if the AC, maybe try adjusting the tensioner to remove some slack.

 

[chuck2000xj]

Thats what I have to do.....tighten it up a bit. Should take care of the squeal.

 

[87manche]

just replace the belt if you're screwing with the tensioner anyway.

 

[Ivan]

Have you completely ruled out the AC clutch as the cause of the squeeling? You may want to check that too......

 

[DrMoab]

It's probably the belt. Tighten it till it scares you then tighten it a little more. They need to be pretty damn tight.

 

[87manche]

Have you completely ruled out the AC clutch as the cause of the squeeling? You may want to check that too......

usually those squeal whe nthe AC is off, then it goes away when you turn it on because the center and the outer are locked up. Unless it's slipping. There's an air gap adjustment for them, but I've never had to do it.

 

[old_man]

It's probably the belt. Tighten it till it scares you then tighten it a little more. They need to be pretty damn tight.

Nothing like replacing water pump/power steering/alternator bearings. hasta

Verify it is a slipping belt first. Get some belt dressing in a spray can and coate the belt while it is running. If the sound varies or goes away it is the belt. Belts that are old, dried out, or have been slipping for quite a while can get hard and basically lose traction. The belt dressing may help but overtightening can lead to a bunch of other failures. Ideally get a belt tension gauge unless you have calibrated your fingers from 20+ years of wrenching.

 

[drewbsking]

Nothing like replacing water pump/power steering/alternator bearings. hasta

Verify it is a slipping belt first. Get some belt dressing in a spray can and coate the belt while it is running. If the sound varies or goes away it is the belt. Belts that are old, dried out, or have been slipping for quite a while can get hard and basically lose traction. The belt dressing may help but overtightening can lead to a bunch of other failures. Ideally get a belt tension gauge unless you have calibrated your fingers from 20+ years of wrenching.

100% agree with the belt dressing. Mine will squeak on a cold start on a hot day with AC on. A litte dressing will not hurt. JUST DONT PUT IT ON THE SMOOTH SIDE. Dont ever tighten the belt. The cheap cricket belt tentioner tool (around 10 bucks) is a piece of you know what, but it will get it close.

 

[DrMoab]

I'd be willing to bet that 80% of you are running the belt too loose. I've seen this over and over. Even using a tension tool most of them I look at are on the loose side.

 

[IslanderOffRoad]

I'd be willing to bet that 80% of you are running the belt too loose. I've seen this over and over. Even using a tension tool most of them I look at are on the loose side.

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And I've had a compressor replaced by a shop who didn't tighten the belt near enough