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Loud sound from AC?

S

spinaldex

NAXJA Forum User
Location
Oregon City, OR
I'm an idiot when it comes to the AC compressor so I apologize for this question:

The front of the pulley on the AC compressor has an extra .. disc? .. that starts and stops on it's own. Its loud as hell all of a sudden. It wasn't up until a week ago. The only change is that we started using the AC again more frequently because we had a heat wave. I made a video:

http://www.youtube.com/watch?v=IDkyA67Dpl8

AC still functions fine. If I turn it on full blast ... no change whatsoever. If I turn off AC, no change at all. Blasted it with WD-40. No change. Is it internal to the unit? Is it on it's last leg?
 
that's the ac compressor clutch engaging and disengaging. it's working as it should be could just be noisy from lack of use but it does sound like its on it's way out. it sounds like a scraping sound in the video, is that accurate? if so I would replace it before it seizes up.
 
Sounds like the clutch is dragging. Remove the belt and check the bearing by wiggling the pulley. If it's bad, you have to replace the pulley or change the pulley to an earlier model with a replaceable bearing.

It's been covered before, I just can't search cut and paste well on an iPhone.
 
Found the write-up. Honestly, that sounds like a lot of work considering you can get a replacement re-manufactured entire assembly for $100 w/ shipping from eBay? But I guess each person approaches a problem differently. With that said, I read somewhere that you should never swap an AC out yourself due to the toxic gases, is that true? I was thinking you could just run the AC until the juice runs out or figure out a way to slowly drain it using one of those hoses you use with the refill cans and then you should be safe to disconnect the whole thing. Am I wrong?
 
And then .. I read that if you replace an AC compressor you also need to replace the condensor, accumulator and expansion valve as they are non-serviceable? Is that true?
 
Ok, last question then:

Could I just go to a junkyard and pull one thats pre-97, so its a servicable one, and pop it on instead or is there a bunch of stuff that won't fit? Or, if I wanted to be cheap, could I just swap in another junkyard 00-01 one? The junkyard wants $30 for it, and I'm almost willing to risk it just to get it up and running quickly since I'm worried it could seize.
 
The advantage of replacing just the pulley is that you do not have to open up the A/C system -- that is, you do not have to take it to a shop that can remove all the R-134a refrigerant, open the system to air, replace the compressor, dryer, and expansion valve, then take it back to the shop again to get all the air vacuumed out of the system and recharge the system with refrigerant. Then you still have to chase down leaks that may have popped up because several joints were opened then hopefully resealed.

The advantage of replacing the full compressor is that you will be starting with a new one, unless you get one from a junkyard, in which case you have all the disadvantages and no upside at all.

I had a car (not Jeep) that had over 250kmiles on it and the A/C had never needed any repairs. I don't think you can assume that the compressor is close to worn out.

Given your circumstances, I would opt for just replacing the clutch and pulley and not open up the refrigerant system at all.
 
The problem is that I'm not sure how to perform the job of pulling things out of it and replacing them. I thought I had found a write-up but I just found a reference to it, so I'm still unsure of how difficult it would be. Replacing an entire unit is possibly more feasible considering my technical skill as I could drive it to a shop, have it drained, drive it home, pull a few bolts and disconnect a few lines, replace it, drive it back down and have them refill it, right?
 
I listened to your video and it sounded to me like your compressor clutch is not releasing completely -- in other words, the two mating surfaces are still touching when the clutch is released. I'm not positive about this because it assumes that the mic and my speakers are properly reproducing the sound.

Please check to see if this is what is happening -- it may be a matter of adjustment instead of repair/replacement.

In the meantime, I'm off to see how this all comes apart.

I'm out of touch all day tomorrow, so it may be I don't get back to you until mid-Monday.
 
sidewaysstarion said:
to me it sounds like a bad compressor clutch bearing.
Click to expand...
OK, it could well be.

It may be possible to check to see if the clutch face is dragging by trying to slip a piece of paper between the clutch and pulley (engine OFF of course). There is supposed to be an air gap of about 0.015" to 0.030".

If there is too much rust buildup it will be hard to tell if the gap is really there. In that case you can take the clutch off and see if you still get the noise with the clutch gone. If so, SidewaysStarion is right -- the pulley bearing is bad and needs to be replaced.

I found this youtube video that shows how to remove and reinstall the clutch without removing the compressor. Note that you do NOT have to remove the serpentine belt even though the video shows how to remove it.

http://www.youtube.com/watch?v=V_s8AOqEMgw

HTH

-HappyDog
 
Just to make sure I understand this correctly:

1. Some people here believe the bearing in the clutch is bad. So, using that video as a reference I could get a replacement clutch and install it and my problem could be fixed?

2. Other people believe the complete pulley assembly's bearing (not the clutch bearing, but the bearing on the compressor's pulley) needs to be replaced. Someone said it was non-serviceable at the beginning of this thread. Is that correct?
 
I checked w/ AutoZone and they list part #s for the clutch bearing and shims, but they don't actually carry the actual clutch itself. I was thinking that it would make sense to replace the clutch itself as well as the bearing as the clutch can be worn over time as well, right?
 
Ok. so I'm sorry about all the stupid posts as I'm trying to learn all of this. From what I can see based on the videos and reading I've done over the past couple hours as well as seeing what's going on in mine:

Since the sound is coming 100% of the time from the compressor, its the bearing on the pulley, not on the compressor because it doesnt change when the compressor is engaging.

Since I have a 2000 XJ, the bearing in the pulley is not serviceable. Therefore, I'm left with two options:

1. Get a replacement compressor for my year and swap the pulley assembly from it to mine.

2. Get a early-mid 90's Sanden compressor from an XJ and swap it's servicable pulley/bearing assembly on to mine.

Am I correct with the two options above?

If so, then junkyard seems like a good first attempt since it's a lot cheaper to get an AC that way plus I gain the benefit of being able to buy bearings for it going forward if it were to happen again!
 
I thought the objectionable sound occurs only when the clutch is not engaged and the compressor is not turning. It certainly sounds different then.

As for your question about replaceable bearings, I don't know the answer.

I have never worked on a Jeep A/C compressor clutch, but the ones I have worked on operated as follows:
When the clutch is NOT engaged, only the clutch bearing is in use
When the clutch IS engaged, only the compressor bearing is in use

I hope someone with experience with 2000 XJ A/C clutches weighs in with the definitive answer.
 
Are you sure the noise is coming from the front of the compressor?

The alternator is directly below the compressor and its bearing is always running -- the difference in sound when the A/C clutch kicks in could be due to the additional loading on the belt, and thus on the bearings of all the other pulleys the belt runs over.
 
Ok, so I should write posts right after I come back from my vehicle because what I write will be much more accurate ...

So, the grinding noise happens when the clutch is not spinning. Once the clutch spins with the pulley, the grinding noise stops.

Therefore, that would indicate the problem is with the clutch's bearing and not the pulley, right?

So, I've heard people having trouble sourcing the bearing for the clutch. I have seen a few full replacement clutch sets. Should I just pick one of those up or just go with a bearing?

Thanks.
 
Listening to the video it is the clutch bearing that is bad. I have not worked on a 2000, but I replaced the clutch bearing on a 96 XJ with no problem (87, 89 and others, they all pretty much the same style I thiink)

Try www.ackits.com for the bearing and they have a DIY AC blog forum where their tech guys will help you. You need a puller tool set, you can rent it for free (with a deposit).

http://www.ackits.com/merchant.mvc?Screen=CTGY&Store_Code=01&Category_Code=Jeep00Cherokee_4-0

Here are some you tube videos on how to do it.

https://www.google.com/search?q=you...s=org.mozilla:en-US:official&client=firefox-a

These guys may sell you just the bearing:

http://www.dixieautoair.com/

Ebay has the bearing for $9-$13

http://www.ebay.com/itm/NEW-AC-COMPRESSOR-PULLEY-CLUTCH-BEARING-CROSS-35BD219DUK-35mm-55mm-20mm-35x55x20-/160935247937?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A2000|Make%3AJeep|Model%3ACherokee|Engine+-+Liter_Display%3A4.0L&hash=item25787d0041&vxp=mtr

http://www.ebay.com/itm/NEW-AC-COMP...iter_Display:4.0L&hash=item257c8302f3&vxp=mtr
 
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