A/C Grinding when started
Thread Starter
Pro
Joined: Feb 2007
Posts: 538
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From: Orlando FL
A/C Grinding when started
So OK. I rarely drive my car lately as it is very very hot down here in FL right now, and even with tinted windows, a black interior is HOT. I put in a new can of the r35 plus lubricant, and let it run for a long while to make sure it worked it's way thru the system.
So the other day, started up my 95 LT1, and turned the A/C on. It made an intermittent sound like a "eeehhhhh (pause) ehhhhh (pause) ehhhh..."
So I immediately turned it off. Went a bit down the road, then turned it on and it came on fine with no problems.
WHat the hell could this of been? Any ideas? Almost sounded like it was binded up a little or something.
So the other day, started up my 95 LT1, and turned the A/C on. It made an intermittent sound like a "eeehhhhh (pause) ehhhhh (pause) ehhhh..."
So I immediately turned it off. Went a bit down the road, then turned it on and it came on fine with no problems.
WHat the hell could this of been? Any ideas? Almost sounded like it was binded up a little or something.
Burning Brakes
Joined: Dec 2000
Posts: 1,161
Likes: 0
From: Orangeburg, NY
It sounds like the freon is low. The a/c clutch will engage intermittently when the freon is low.
Start up the car and put the a/c on full. Open the hood and look at the a/c unit. The pully (outer part) will be rotating. Look at the inner part of the pully (Clutch) If it the freon is low the clutch will engage/disengage, thus causing the sound you mention. If you raise the idle the sound typically goes away, due to the clutch engaging at higher rpm's.
If this is the case,(clutch running intermittently) then add a can of freon. Start the engine and let it idle. Turn on the a/c to full. Attach the hose to the can, pierce the can, then attaching the hose to the proper connection, the low pressure side. As the car is idling turn the valve slowly until it is fully open. Turn the can upside down, the hose is on the bottom. Move the can from the twelve o'clock postion to the three o'clock then back to the twelve o'clock position every fifteen seconds or so. You will feel the can get cold. When the can becomes warm, an indication it is empty, close can's valve, then remove the hose from the low pressure valve. This should do the trick.
Start up the car and put the a/c on full. Open the hood and look at the a/c unit. The pully (outer part) will be rotating. Look at the inner part of the pully (Clutch) If it the freon is low the clutch will engage/disengage, thus causing the sound you mention. If you raise the idle the sound typically goes away, due to the clutch engaging at higher rpm's.
If this is the case,(clutch running intermittently) then add a can of freon. Start the engine and let it idle. Turn on the a/c to full. Attach the hose to the can, pierce the can, then attaching the hose to the proper connection, the low pressure side. As the car is idling turn the valve slowly until it is fully open. Turn the can upside down, the hose is on the bottom. Move the can from the twelve o'clock postion to the three o'clock then back to the twelve o'clock position every fifteen seconds or so. You will feel the can get cold. When the can becomes warm, an indication it is empty, close can's valve, then remove the hose from the low pressure valve. This should do the trick.
Thread Starter
Pro
Joined: Feb 2007
Posts: 538
Likes: 0
From: Orlando FL
well my vette is pretty much a winter car, I hardly drive it in the summer as it rains so much. So this afternoon I actually picked up a gauge so I can hook up and check the pressure. Seems it had just a little too much pressure in the system! So I purged just a little out to drop it where it should be (not very much!) (i know, i know - bad for the environment).
Hopefully that is what the problem was!
Hopefully that is what the problem was!
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Noise is never good. Your clutch gap could be too wide, or it could be low/out of oil and about to grenade a million bits into the lines and condensor at which point you will spend anywhere from 10 to 100% of your Vette's value fixing it (depends on the condition of your Vette of course). You can check the air gap with a feeler gage - it needs to be .020 inch. That's the distance between the front of the clutch and the pulley with the engine off. If it's right, go to an a/c shop and let them check your charge. You'll be dollars ahead (and if they want more than 50 Bucks to do this go to another shop - Poop Boys says they'll do it for $29.95, but you might need to pay a little more because they're trying to figure out if there's enough oil in it to keep it happy).
