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Hi,
After changing the compressor clutch this winter and having the gas load controlled, I drove a little with the A/C engaged.
However, a loud whistle is heard when I turn on the air conditioning. No whistle is heard when turn off.
It seems to me that the clutch became very hot... Is it possible that the compressor does not rotate normally and the belt slips and whistles on the pulley?
However, I don’t see any wear on this belt, but I haven’t driven much...
Maybe I could test the compressor by removing the belt and locking it in with key on (and AC on ;-))?
The clutch has to be on a certain distance from the clutch plate. I don't remember the spec but if it's too far away you will not get good clutch engagement. Did you measure that distance when you put it on?
This evening, I checked the gap : it's correct about 0.015¨ (at the max of specs 0.01 to 0.015'')
The bearing of the cluch has no play and make no strange noise. The pulley and belt have no marks of wear.
I removed also the belt and key/AC on 'on' : the pulley turns quite freely.
I don't see any problems on cluth side...
I don't kwow if the compressor has the correct amount of oil. I asked the people who checked the gas and they said to me all was fine... but I didn't personnaly check this. And anyway, I don't know how to do this ;-)
Last edited by chris383; Jul 17, 2023 at 04:14 PM.
Good question. I assume I put the key in, but I must eventually check this...
One thing I forgot to say : the AC works really well ! A lot of cold air (almost too much for my wife ;-)) and a lot of water under the car after the trip. I think if the clutch spins on the shaft, the AC will not work well : correct ?
After talking with a person from France, who also has a LT-1 with AC, I decided to change my original A6 compressor to a new, more modern one
I’m still hesitating between the Pro 6 ten (at Corvette Central for example) or the Four Seasons 58078 (with pulley 5.75').
He also had the possibility to take a Sanden, but the necessary adptations are numerous while the others seem easier to assemble without big modifications.
Does anyone have experience with either of these compressors?
I did a few tests:
- I removed the belt from the compressor and connected the solenoid: the compressor runs smoothly by hand.
- without connecting the solenoid, the pulley without the belt also rotates freely. No ball bearing noise. No wear on the belt or pulley.
I found however that I put a play between the clutch and the pulley of 0.012" (on a forum) and that the set prescribed on the workshop manual (that had not seen...) is between 0.022 and 0.057"!
I’ll correct the game at 0.023" and try again to see if it changes the whistle.
Every time I come back to this thread your description of a whistling noise throws me off. Insufficient clutch gap doesn’t sound like whistling to me, it would be more of a squeaking or rubbing sound.
Here is my brand new Vintage Air compressor with insufficient clutch gap on one side, does yours sound like this?
I recently purchased a new compressor four seasons replacement of the original A6 compressor.
I have already done a blank assembly and to my surprise, it is mechanically mounted without problems instead of the A6!
The screws are metric, but this is no problem.
On my A6 compressor, I had to mount a pressure switch (it is flat at the back) instead of the original superheat switch because it was impossible to mount it in the intended location: the hole was too short for the temperature probe.... This is for some reason.
I had to modify the wiring for this new pressure switch.
Now, the manufacturer of the new compressor says to use the Superheat switch :
My question:
Can I mount the flat pressure switch again instead of the Superheat on this new compressor ?
In my opinion, it must work because on my old, it seems that everything was ok.
I also searched how I could electrically control these switches on the forums, without success...
I found that the pressure switch has no continuity between the connection pin and the switch body
After some research, I know a little more about the subject.
I’m thinking of putting a superheat switch on my new compressor.
I have two in stock: one that has a contact between the two terminals and one that does not!
For me, there must be no contact: if the pressure or temperature exceeds the limit values, the contact is made and therefore, the grounding is put. This melts the thermal fuse that stops the compressor.
Hi !
I've bought and now mounted my new 4-Seasons Compressor.
I painted it in black. It is full adaptable on my LT-1. The only difference is the metric mounting hardware : not a problem right here in Switzerland ;-)
I did not see that the flange is an aluminium material : with the manual based torque, the threads did not resist !
Therefore, I mounted counter-nuts and problem was over.
After a gas charge in my local mechanics, it seems that all is working good now : no strange noises, no drag on motor.
compressor whistling
