A/C compressor squeeks on start up

[Fred85]

It's done this a few times now, but i start my jeep up and turn on the a/c and there is this horrible squeeling so i turn it off and it goes away. I wait about ten seconds, turn it on again and the squeeling isn't quite as loud but very much there. So i turn it off again and wait another ten seconds, turn it on again and the squeeling goes away. It only ever does this right after start up, never after it's been running a while.

What could this be?? A/c runs just fine, air is cold. I thought maybe the belt doesn't have enough tension, but the squeeling only starts when the compressor starts and stops when the compressor stops. The belt seems to be in good condition also.

I'm hoping this won't end up costing me a few bills..............but any help will be greatly appreciated.

 

[old_man]

Sounds like a loose belt to me.

 

[red91]

Sounds like a loose belt to me.

go to napa, and get a belt tensioner tool. SHould be about $15.00....adjust your belt properly and more than likely it will dissapear.

 

[Fred85]

i forgot about this thread

So, i wanted to make sure that the squeek actually came from the compressor so i started the jeep up and turned on the a/c and stuck my head under the hood. It turns out the the squeek is coming from around the idler pulley or power steering pump pulley.........hmmm

 

[AZ Jeff]

i forgot about this thread

So, i wanted to make sure that the squeek actually came from the compressor so i started the jeep up and turned on the a/c and stuck my head under the hood. It turns out the the squeek is coming from around the idler pulley or power steering pump pulley.........hmmm

I am still betting belt tension is the problem. The AC compressor increases the load on the belt IMMENSELY over without it being on. The belt squeals a bit until it warms up (due to slipping and engine heat), and then the squeal ceases.

Do a tension check first.

 

[langer1]

One other thing. Have you charged your A/C lately, belt slipage at startup can be a sign of a over charged system.

 

[Fred85]

oh yeah i forgot to add, i did tighten the belt and the noise only lessened a little bit. I didn't wanna tighten it too much without a guage on it though........

I went to NAPA to pick up a belt tensioner, they didn't have one, but they said they could order a v-belt tension guage. That was the only kind of belt tension guage they could find in the computer, so i didnt get one

And, i dont know about the A/C charge because i only bought the jeep 1000 miles ago

 

[langer1]

oh yeah i forgot to add, i did tighten the belt and the noise only lessened a little bit. I didn't wanna tighten it too much without a guage on it though........

I went to NAPA to pick up a belt tensioner, they didn't have one, but they said they could order a v-belt tension guage. That was the only kind of belt tension guage they could find in the computer, so i didnt get one

And, i dont know about the A/C charge because i only bought the jeep 1000 miles ago

Then it sure could have been over charged, that noise is caused by liquid freon getting into the copmressor, if so it will ruin the compressor.

 

[Fred85]

hmmm, but the noise doesn't come from around the compressor............

 

[langer1]

hmmm, but the noise doesn't come from around the compressor............

I could swear this thread says compressor squeeks on startup. The belt is what squeeks because the compressor is trying to lockup if the charge is to high. Liquid freon backs up into the compressor, liquid can't be compressed. It's just one thing to check if the belts not too loose.

 

[Fred85]

Well i need to get a tension guage first

I 'spose the title should've read "squeel when A/C is turned on upon startup"

How would i check it if it overcharged?....i guess i need to hook up a pressure guage one of the service ports?, and if it's overcharged why does it only squeel when the belt is "cold"??

 

[langer1]

Well i need to get a tension guage first

I 'spose the title should've read "squeel when A/C is turned on upon startup"

How would i check it if it overcharged?....i guess i need to hook up a pressure guage one of the service ports?, and if it's overcharged why does it only squeel when the belt is "cold"??

The simple answer is that when the compressor it running the refrigerant is turned to a gas, after it’s off and everything returns to the same pressure some of the liquid gets forced back up the compressor suction line. One way is to look for frost on the compressor suction line. The other way it to test the Delta-T. There is also a temperature tape you can get the will show you how full the system is.
As for pressure you need to use a Manifold pressure gauge set, because you need to know the differential between the low and high side.

 

[smccollamjr]

Check the idler pulley. Mine was a little loose and when the compressor kicked on it would cause the pulley to rub against the mounting bracket.

 

[jlex]

Did you get any oil on the belt when working on it... or did your AC compressor throw some fluid onto it? How old is the belt... maybe its glazed over. Why not take some denatured alcohol to the belt to see if that makes a difference before doing anything else...
regards,
jlex.

 

[Pioneer89XJ]

I would bet the belt is too loose. Both XJs (89 & 98) I've owned have had the Cherokee Squeal when the belt stretched and was a tad too loose. Tighten it a little more and see if gets better. Most people, including myself, underestimate the correct tension of the belt.

 

[bustednutz]

On my 98 if its raining out, and the car has been parked outside all day, it will squeel and slip. Why is that? Just damp air? No moisture has gotten under the hood.
I have to rev it a few times to get it to grip again. Its a fairly new belt too.
I think I may have to adjust mine as well.