AC Compressor trouble
#1
Senior Member
Posts like a 4 Banger
Thread Starter
Join Date: Mar 2006
Location: Maryland
Posts: 112
Likes: 0
Received 0 Likes
on
0 Posts
AC Compressor trouble
Ok...Try to stick with me on this one.
I have a weird screaching sound coming from this thing.
On the AC compressor; there is a pulley. Then there is some unknown part...then there is the center of clutch that spins when you turn the AC on.
The part that is making the high pitch sqeeking is the unknown part....and it'* doing it with the AC off.
The car will be running, only the pulley spinning as it should. But maybe 20 times a minute for 2 second spurts....that unknown part will spin (about 1/2 revolution) and make this horrible sound.
Any Idea what is going on? Can i just put a new belt on to bypass the compressor to verify it is truely my problem? Or do I need to buy a bypass pulley of some sort? Or is there a way to fix this all together.
Thanks.
-IKZ
I have a weird screaching sound coming from this thing.
On the AC compressor; there is a pulley. Then there is some unknown part...then there is the center of clutch that spins when you turn the AC on.
The part that is making the high pitch sqeeking is the unknown part....and it'* doing it with the AC off.
The car will be running, only the pulley spinning as it should. But maybe 20 times a minute for 2 second spurts....that unknown part will spin (about 1/2 revolution) and make this horrible sound.
Any Idea what is going on? Can i just put a new belt on to bypass the compressor to verify it is truely my problem? Or do I need to buy a bypass pulley of some sort? Or is there a way to fix this all together.
Thanks.
-IKZ
#2
DINOSAURUS BOOSTUS
Expert Gearhead
That sounds like a bad bearing on the AC compressor. The pulley free wheels on the bearings until the clutch locks it in.
Does the sound go away if you turn on the AC and it engages?
Does the sound go away if you turn on the AC and it engages?
#3
Senior Member
Posts like a Turbo
Join Date: May 2003
Location: B'ham.AL
Posts: 435
Likes: 0
Received 0 Likes
on
0 Posts
The clutch plate is pressed on the center compressor shaft and comes with a .020” air gap from the factory. When you turn the AC on the strong electric magnet pulls the clutch plate to the pulley thus turning the pistons in the compressor. So over time this air gap closes and the clutch plate starts to scrape when the AC is off. Sounds like all you need to do is increase your air gap a little (pull the clutch plate away from the pulley).
I have heard AutoZone rents or loans this tool out to adjust the air gap.
This is what the tool looks like and several companies sell similar versions.
http://www.sjdiscounttools.com/kdt3340.html
This link will hehp.
http://www.autoacforum.com/messagevi...threadid=15161
I have heard AutoZone rents or loans this tool out to adjust the air gap.
This is what the tool looks like and several companies sell similar versions.
http://www.sjdiscounttools.com/kdt3340.html
This link will hehp.
http://www.autoacforum.com/messagevi...threadid=15161
#5
Senior Member
Posts like a 4 Banger
Thread Starter
Join Date: Mar 2006
Location: Maryland
Posts: 112
Likes: 0
Received 0 Likes
on
0 Posts
When I turn on the AC....the unknown parts spins wildly (kinda oblong; like it isn't being held on by anything. The sound kinda subsids....
Taking a better listening to everything...there is a noticable grumble/ grinding coming from the compressor area.
How to I go about bypassing it to confirm a bad compressor?
Thanks a lot for the links...hopefully thats all it needs (more of an air gap.)
Taking a better listening to everything...there is a noticable grumble/ grinding coming from the compressor area.
How to I go about bypassing it to confirm a bad compressor?
Thanks a lot for the links...hopefully thats all it needs (more of an air gap.)
#6
Senior Member
True Car Nut
Originally Posted by IKZ
How to I go about bypassing it to confirm a bad compressor?
Just remove the serpentine belt and run the engine briefly without the belt, listening for the difference. Do not run the engine for more than a minute as without the drive belt, you have no water pump for engine cooling, and it ain't real good to run without the alternator. This is also an easy way to check for a noisy water pump, power steering pump or idler. Running w/o the belt will probably set a check engine light, which you might have to clear by disconnecting the negative battery cable if you don't have a scan tool or access to one. Then, you've got to re-do all your radio pre-sets and so on.
When I bought my 90 Buick LeSabre it had a short belt routed to bypass the AC compressor, so I know that can be done. I imagine you would need to figure an alternate routing, then measure the distance around the pulleys allowing for the tensioner, then buy a belt the appropriate length with the right number of ribs.
#8
Senior Member
Posts like a 4 Banger
Thread Starter
Join Date: Mar 2006
Location: Maryland
Posts: 112
Likes: 0
Received 0 Likes
on
0 Posts
bill buttermore--_Thank you very much. Tomorrow morning I'll take the belt off and see how things go.
Hopefully this is an isolated problem that can be fixed easily and cheaply (i.e. by me).
Thanks again for the input fella'*.
-IKZ
Hopefully this is an isolated problem that can be fixed easily and cheaply (i.e. by me).
Thanks again for the input fella'*.
-IKZ
#9
Senior Member
Posts like a 4 Banger
Thread Starter
Join Date: Mar 2006
Location: Maryland
Posts: 112
Likes: 0
Received 0 Likes
on
0 Posts
OK.....I took off the belt and started the engine. And what a beautiful sound it was. Not sqeeking, grinding or squelling.
I certainly dont have money yet to replace my compressor. But i do have enough to bypass it. I just cant seem to figure out the routing of the belt to bypass the ac, but still make everything else spin in the proper direction.
Has anyone done this before? Can you lead the way?
http://www.dormanproducts.com/cgi-bi...tegory_list=:0
I found this at all the parts stores for about 37 bucks. If I buy this do i need to buy a new belt, or does the compressor come out and this go in its place?
I certainly dont have money yet to replace my compressor. But i do have enough to bypass it. I just cant seem to figure out the routing of the belt to bypass the ac, but still make everything else spin in the proper direction.
Has anyone done this before? Can you lead the way?
http://www.dormanproducts.com/cgi-bi...tegory_list=:0
I found this at all the parts stores for about 37 bucks. If I buy this do i need to buy a new belt, or does the compressor come out and this go in its place?
#10
Senior Member
True Car Nut
Well, I'll be...Yeah, it looks to be the same diameter and bolt in place of the AC compressor. So, you would use the same belt. And that'* about the price of a new belt anyway, so I would say buy the Dorman pulley. Is your AC system still charged? Is your car using R-12 refrigerant? There should be a sticker saying so somewhere under the hood. If so, you are gonna want to take your car to an AC shop anyway to have them suck out your refrigerant so it won't harm the environment. Some say this should be done even for R-134a, while others say R-134a can be safely released into the atmosphere. Usually shops will suck out your R-12 for free as they can sell it for big $$.
Anyway, once the system is empty, you can unbolt the compressor, unbolt or wire the hoses securely out of harm'* way, and bolt in the new part. I would think you would want to plug or cap any open ends of the system so that dirt cannot enter so when you have the $$ to fix it, it will be useable.
I'll bet that Dorman pulley comes wiith instructions, too.
Anyway, once the system is empty, you can unbolt the compressor, unbolt or wire the hoses securely out of harm'* way, and bolt in the new part. I would think you would want to plug or cap any open ends of the system so that dirt cannot enter so when you have the $$ to fix it, it will be useable.
I'll bet that Dorman pulley comes wiith instructions, too.