I'm getting alot of chatter out of my AC pump when it isn't engaged. I thought it was the clutch, well the clutch was bad (bearings missing). Still chatters until the clutch engages, then it quits. I do have the clearance set correctly. Seems as if it was the pump it would always do it. Any suggestions?

97 F150
4.6l

Brian

EDIT* AC is still cold

 

I'm thinking you have the same as me, in that you're low on juice and maybe a seal has allowed leaking. I'm on my way to the dealer to pick mine up, they say the compressor/ clutch and pulley have to be replaced. 1000 bucks, so I said no dice on replacing all those. I gotta find out where it's leaking first. a .25 cent o-ring or a 400 dollar compressor assembly? Hummm, we'll see.

 

I found that yes indeed it is leaking at what appears behind the pulley. Now, just barely, but we'll see how much juice it takes to be cold again. Guaranteed the noise is the compressor trying to pump what it has. I'm going to have it topped up and be set till it goes kaput for real. We even checked for odd noises, none so the compressor is still ok, and the clutch too. It just cycles way too much.

 

Problem solved. Got the system re checked, and said it was low on refrigerant, I figured, so they topped up and it snows in the truck again. No more noisy compressor, no more irratic cycling, just the way I like it now. The compressor has a very small leak, but normal they said. Not cause for replacing. Very happy now.