AC squeal

Landerson1515 · **Joined:** Thu Nov 14, 2013 10:55 pm **Posts:** 9

So I had a terrible squeal at idile on my crd coming from the serpentine belt. So today I replaced it. After start up squeal had went away so I took it for a drive. It is finally getting warm up here in North Dakota so on my drive I turned on the AC for the first time this year. When I did I has a squeal again from AC. I was wondering if any of you would have any suggestion for me? Any help would be appreciated. Thanks in advanced.

diesel_guy86 · **Posted:** Sun May 18, 2014 12:04 am

Your a/c compressor could be shot. Happened to me last year on my duramax. Something tied up inside and caused the belt to slide over it instead of turn it.

Landerson1515 · **Joined:** Thu Nov 14, 2013 10:55 pm **Posts:** 9

Is there anyway I could test the compressor befor just replacing it? The AC does still work.

diesel_guy86 · **Posted:** Sun May 18, 2014 12:22 am

Does it only do it when the ac is on?

Landerson1515 · **Joined:** Thu Nov 14, 2013 10:55 pm **Posts:** 9

Yes it only squeals when AC is on

flash7210 · **Posted:** Sun May 18, 2014 7:11 am

Might be your belt tensioner that is bad.

CRD05il · **Posted:** Sun May 18, 2014 4:17 pm

flash7210 wrote:

Might be your belt tensioner that is bad.

I agree I have the same problem and I believe it is the belt tensioner

diesel_guy86 · **Posted:** Sun May 18, 2014 4:29 pm

How would the tensior know if the ac is on or not?

CATCRD · **Posted:** Mon May 19, 2014 11:29 pm

diesel_guy86 wrote:

How would the tensior know if the ac is on or not?

More load on the belt with ac on. Tensioner can't maintain the grip required.

naturist · **Posted:** Mon May 26, 2014 9:52 pm

Ok, I have this same problem right now. I just had the belt tensioner replaced a couple months ago as I was getting racket from the belt. That fixed the noise until I just recently turned on the AC. I get the the same noises as the OP, only when the AC is engaged. AC does cool the air just fine. So I'm wondering of it might be the AC clutch that is the problem?

CATCRD · **Posted:** Mon May 26, 2014 11:19 pm

It's probably your alternator clutch pulley.

dgeist · **Posted:** Sun Jul 13, 2014 8:25 pm

I have a similar squeal going on (since we're dog-piling the original post...). It WAS coming and going on and off idle depending on if the engine was warm, speed, etc. In the past few days, it's been squealing all the time (doesn't really sounds like a "belt noise"m BTW, and the belt is only 6 months old), with some minor variation with load, etc.

I tried spraying a little WD-40 in each of the pulleys this morning. It didn't do anything. They I broke down the front end to get the belt off. All the pulleys spun freely (that are supposed to move) and had very little lateral play, if any. After re-assembly, I sprayed a little WD-40 on the toothed surface of the belt itself, and things got quieter for a while. Once the spray dried, the noise cam back and varries only slightly with engine speed and load. The alternator clutch is less than a year old, and the noise sounds like it's mostly coming from the other side.

Ideas?

Dan

thermorex · **Posted:** Sun Jul 13, 2014 10:02 pm

If it's a belt squeal, use silicone spray on the inside (grooved side) while the engine is running. Did that on the Cherokee 3 months ago and never had an issue, that belt was chirping new...

Mike92104 · **Posted:** Sun Jul 13, 2014 11:11 pm

What does the alternator pulley look like? Good chance it's the clutch pulley.

dgeist · **Posted:** Mon Jul 14, 2014 9:39 am

Mike92104 wrote:

What does the alternator pulley look like? Good chance it's the clutch pulley.

It looks clean, dry, and less than 9 months old. Also, freewheeled with near 0 resistance when I had the belt off... Also, I've had the clutch go before and it doesn't sound like this.

I'm starting to think this might be the tensioner itself since it's not really the same kind of noise you get when the pulleys run try/seize. Also, the fact that a little fluid on the belt made it quiet suggests the noise is slippage. Can anyone describe the noise you get when the tensioner goes tango uniform?

Dan

papaindigo · **Posted:** Mon Jul 14, 2014 11:09 am

Normally when the alternator clutch is going/gone the serp belt tensioner will be noticeably bounding as opposed to barely twitching with the engine at idle speed also there is usually red dust behind the tensioiner plastic cover.

The tensioner is essentially only 2 parts 1) the spring, which can break but I wouldn't think just get weak, that provides the tension and 2) the pulley which can be replaced (it's the same as the serp belt idler pulleys 68211444aa - alternative NAPA 36101 (just lose the big washer) or Precision Parts EP101).

Could just be your belt if it's been on there a while. I've seen them get glazed and slip.

dgeist · **Posted:** Mon Jul 14, 2014 12:23 pm

I'll check behind the cap today. If it's gone, then the parts store and I are going to have words... (granted, you get what you pay for when the reman-ed alternator says "made in china" in a big sticker on the side...)

Dan

thermorex · **Posted:** Mon Jul 14, 2014 1:49 pm

Dan, if you already have the fan out, take a mechanical sthetoscope and at least locate the area... I found I have a slight chirp, almost unnoticeable on the fuel pump. Obviously I thought is a timing belt pulley, till I replaced them with new.

Auberon · **Posted:** Fri Jul 18, 2014 10:25 am

As I understand it many rebuilt alternators include just a one-way clutch rather than a proper OAD compatible with design and I purchased 2 x Goodyear OAD's on a closeout - the literature included had Litens printed on the bottom of the page.
Suggest you make sure and go to the Gates site and view their videos on how to te4st an OAD and then test it properly. You'll know for sure then. The Gates site proper has the text in it so you can print/read it if you prefer.
eg: replace if: shaft spins easily in both directions; OR slips in the drive direction and if it doesn't spin freely and smoothly in the overrun direction or there is not spring feel in the drive direction.
Also the recommendation is that > 9-13 inch lbs torque (1 - 1.5 NM) to turn in the overrun direction then replace also.
+ replace if there is dust as mentioned or metal frags under the cap.

They will squeal when beginning to enter failure mode.
Hope that is useful.

dgeist · **Posted:** Fri Jul 18, 2014 11:15 am

Good details, definitely. I have tested the OAD previously (when first installed) and it is the right type (i.e. not a simple clutch). I did NOT, however, test it when I had the belt off last weekend

.

As a side note, it's more a "high-pitched chitter" than a true belt squeak/squeal that I'm getting, which is why I'm fairly sure it's not the belt itself. Definitely something mechanical not happy. I just need some time to figure out if it's the OAD, the tensioner, both, or something else. This thread has been pretty informative:
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=78875

Dan

Auberon wrote:

As I understand it many rebuilt alternators include just a one-way clutch rather than a proper OAD compatible with design and I purchased 2 x Goodyear OAD's on a closeout - the literature included had Litens printed on the bottom of the page.
Suggest you make sure and go to the Gates site and view their videos on how to te4st an OAD and then test it properly. You'll know for sure then. The Gates site proper has the text in it so you can print/read it if you prefer.
eg: replace if: shaft spins easily in both directions; OR slips in the drive direction and if it doesn't spin freely and smoothly in the overrun direction or there is not spring feel in the drive direction.
Also the recommendation is that > 9-13 inch lbs torque (1 - 1.5 NM) to turn in the overrun direction then replace also.
+ replace if there is dust as mentioned or metal frags under the cap.

They will squeal when beginning to enter failure mode.
Hope that is useful.

AC squeal

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