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4K views 18 replies 4 participants last post by  Ranger 
#1 ·
Since warmer weather started, I hear a chirping sound every time a/c compressor comes on. Been reading other threads about this. Those threads identified the serpentine belt as possibly being not tight enough, and the compressor chirps \ slips each time it engages. (my translation of what I remember reading in the chirping threads)

Took it to my mechanic who indicated it is the clutch inside the a/c compressor that is causing the chirping sound.

My question to the experts here... Anyone else had this diagnosis? It sounds reasonable to me... but I dont remember anyone here suggesting that that could be the cause of the chirping.

Thanks to all...

This forum is just fantastic ... especially for those of us who are new to Cadillacs...and who are...should I say... mechanically challenged.
 
#2 ·
I can't explain that. The clutch is electromagnetic. The two plates are drawn together magnetically. Rubber slipping chirps, steel doesn't. Run the A/C and use a spray bottle or a squirt gun to wet the clutch pulley and see if the chirping goes away while wet. If so, it's the belt or the tensioner is not tight enough.
 
#3 ·
Hey, mine does the same thing. I've replaced the belt, and the tensioner with one from Rock Auto, Also replaced the idler pulley. I'll have to try the water trick next time its warm again and I hear it.

I was beginning to question something with my AC Clutch as well, but I don't know enough about it.
 
#5 ·
Response from RANGER:

{Rubber slipping chirps, steel doesn't. Run the A/C and use a spray bottle or a squirt gun to wet the clutch pulley and see if the chirping goes away while wet.}

Here is an update. Ran the A/C at 60 F, and I heard the AC compressor engage many times... and sounds like two metal plates banging into each other. A definite metal on metal sound vice a rubber/belt slip as pointed out by RANGER. But, I can't get any chirping sound...UNLESS, I am actually driving the vehicle. Perhaps there needs to be a load on the engine for the squeek/chirp to occur? The metal on metal sound when the clutch engages is audible when driving too as the compressor engages (I can live with it), but the chirping sound is louder. and has to go!!!!

I need to learn how to adjust the tensioner.... or..If I brought it back to my mechanic...would probably be a simple adjustment. Correct?

Again.. thanks for all the assists. I think you need a PHD in auto mechanics to follow most of the discussions here. Quite an education.

I've already had more postive comments on my 1999 Seville SLS with 44K than I can count... and it rides like a dream. Sure beats my Dodge Conversion Van.....
 
#6 · (Edited)
Stickens -

Your symptoms are also just like mine!

But, I can't get any chirping sound...UNLESS, I am actually driving the vehicle.
My chirp is just like that, mine will not do it in Park, only R, or driving, like you mentioned. I'll be following this thread for sure!

I do not believe that the tensioner arm is adjustable. But I'd like Ranger to confirm this. :)
 
#7 ·
The tensioner is a pre-loaded spring arm arrangement - no adjustments other than replacement if the arm is binding or corroded so badly that the system can't maintain tension. IF the spring is weak you will most definitely get a belt chirp - cyclic, as the belt tension varies as it moves over different pulleys. If you can easily get more than 3/4" of belt deflection in the long belt run, then the tensioner is shot or the belt is stretched beyond the tensioner's automatic adjustment range.

A/C clutch plates are metal, usually covered with friction material (like a clutch !). When the friction material wears away the plates clang and rattle when the clutch electromagnet operates. If you can hear the clutch engage from inside the car, it's new clutch time.

The chirp may start when driving because then the P/S pump and alternator are also loaded and overall belt tension increases..........
 
#9 ·
Another update. I can pull the serp belt (pass side) a good inch or a bit more up from the belt's rest position. Over all the belt looks to be in good condition. With only 44 k miles on the engine, seems early to have to replace the belt (if it has stretched). However the car is 12 years old. Perhaps just that length of time would cause it to stretch.

Based on what SUBMARINER and RANGER have said.... I am thinking I should get the belt looked at/replaced. Can my shop take off the existing belt measure it against a new belt to determine if it has stretched? Or is it more likely that the tensioner should be replaced? along with the belt....

Do both at the same time or try just the belt first?

Recommendations???

Thanks!
 
#10 ·
Lose some skin on your knuckles and stick a socket wrench breaker bar down in the square hole in the tensioner arm. Lever it back and forth several times. Strong tension or ???......squeaks and noises ???? Unless all's strong and quiet, something's wrong.

If the tensioner seems strong and the chirp persists, replace the belt. DO NOT resort to "belt dressing" or some such.
 
#13 ·
Update number 2.

I could move the tensioner arm clockwise (standing on the passenger side looking at the belt and tensioner). It looks like there is an indicator mark'/notch on the tensioner arm, with a raised reference indicator on the tensioner frame that is attached to the block. The notch is aligned with the center of this reference indicator on the tensioner. I assume this is an alignment tool used to see if the tensioner arm moves over time.

Any way, I can move the tensioner arm clockwise, but I cannot move the tensioner arm counterclockwise. Not sure if it is because the tensioner is at its limit to one side, or not. Tke breaker tool that I used is only 12 inches...and I couldnt get alot of leverage/power to move the tensioner counterclockwise. When I move it clockwise, there is no noise or apparent binding and does not seem to be loose or weak... (like from rust freezing it solid/still).

In addition, got help with spraying the serp belt with water while keeping the RPMs about 1700. When I sprayed the belt, I still get the sqweak when the A/C compressor engages.

I still think I need to verify that the tensioner is able to move CCwise. Guess I need to get a larger breaker bar (my wife thinks so too...he he he) :).... or an extension on the breaker bar I am using.

If so, then I need to look at the A/C compressor bearings perhaps as the culprit of the sqweaking sound.

I am going to test one more time with wetting down the clutch pulley just to be sure.

Anyways.... looks like I got some more work to do.

Thanks again gents!
 
#14 ·
A cheater pipe on the breaker bar usually will give you the leverage you need, but judging by your comments on how hard it was to move I'd say it is fine. Since water on the belt did not stop the squeak, I think it is safe to assume that it is beyond that. The pulley spins continuously so I can't imagine what would cause it to chirp on engagement. Have you tried post #4?
 
#15 ·
No I have not tried number 4 yet. Ill get a can of compressed air tomorrow and let you know.

Just a thought, could the squeak be coming from another component on the serp belt... ie when the ac compressor activates and creates more resistance on the belt, another component on the belt could squeak?

Just thinking out loud here...

Stick
 
#17 ·
Well... had a chance to look at the belt and tensioner again. Did what Ranger suggested in response #4... compressed air between the clutch plate and the pulley.... got some particles blown out ... but not really a lot..but some.

I briefly removed the belt from the tensioner and played with the pulley and it seemed to be free from any binding at all.

The AC clutch engages with a significant sound still... and the more I drive and listen to the sound as I drive, the more I am thinking that the clutch is in fact the cuprit.... although...just not sure. My mechanic has told me twice that that is the case. He insists the belt is fine and tight enough.

Of course, as Sub stated earlier,... if I can hear the clutch engage from inside the car..its time for a new clutch...ugh. I am going to see what happens with the AC clutch over the summer here in Omaha... and if it gets worse, replace it.

I've read threads about the AC clutch and R&Ring it seems to be a bit more than I am capable of... however I do have access to an auto shop.... but I have no experience doing something like this. Anyone in or near Omaha in here who would want to assist...when it is time?

Again, to all.. my thanks. This forum is great.

Stick:D
 
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