My AC blows cold but I have a vibration from the compressor when at idle to 1600 rpm. Checked the bolts -seem tight, doesn't look like the bracket is bent. ???

It almost sounds like it is straining and causing the vibration??

I dont know hot to fix or correct this situation..

on my last 69 it had this problem and soon thereafter it blew the front seal out and caught fire while i was driving down the road...

had to cut the belt and disconnect the wiring..

hope this doesnt happen to you

Sounds like your compressor clutch is developing problems. Get it checked out before it locks up on you . . . like mine did.

John

Make sure the belt is tight enough. A slightly loose belt will do that. It will also vibrate if the system is overcharged, or overpressured due to lack of cooling at the condenser. Debris or fan problems will cause this. And as others have said, perhaps the compresser is getting ready to go. But check the other things first, and you may save it.

I finally got some free time and put all new belts on. The compressor does not vibrate anymore . But, now when under 1K RPM at idle I hear a metalic tapping bearing type of sound that I can't be sure if it is coming from the water pump area or the compressor. However, when I switch the AC off, the sound stops. I rarely use the AC (only 5 minutes a week to keep things moving), does this sound like something I could live with for awile? or a compressor that is on it way out that will spew oil all over my nice clean engine compartment?

There are two critical bearings in the compressor assy. The input shaft is one, the pully bearing is the other. One of the two take the majority of stress at any one time.

If the compressor makes noise with the clutch turned off, the pully bearing is failing. If it makes noise with the compressor running, the compressor has internal problems.

The pully bearing can be replaced by itself, or with a clutch assy. The compressor would require a rebuild. If either one is failing, you can operate it in the opposite mode and get quite a bit of life. If the compressor is failing, it can run for year if you don't turn on the compressor.

Make sure the noise is not from another area due to increased load on the belt from the compressor.

Thanks for the reply. There is no noise when the compressor is off and no noise when over 1K RPM when the compressor is on. I guess I will keep going down the same path for alittle while longer unless it starts to sound worse. I'll run for a short period once per week just to keep things circulating.