91 AC compressor...loud noise and spits oil/gas from back of unit

[shocker91]

While in the driveway testing why the AC has recently been causing the temp guage to reach near hot, a loud straining sound, smoke and a light oil bellows from behind the AC compressor at very high pressure. Almost appears the smoke/mist/noise is coming from some type of valve attached to where the AC aluminum lines meet at a aluminum block on the rear of the compressor. This process repeats itself every so often however I turned off the AC from inside the truck for fear of more damage. Not very familiar with the differences of AC clutch, compressor etc..and not sure how they work---is this the end of my compressor, clutch? Please advise on next steps or what needs replacing. Thanks.

 

[mrboyle]

It sounds like your compressor is on the verge of locking up (failing). The reason the engine is heating up it due to the added stress the compressor is putting on the engine. In order to properly fix the A/C you will need a new/rebuilt compressor, reciver dryer and orifus tube. You will also need to have the system throughly flushed before you put it back to gether. This is best done by a professional that has the proper equiptment. You will also need to have the system evacuated after the repair is complete but before you add any freon.

 

[Texan01]

actually you'd smell the clutch slipping and notice the burnt paint on the clutch. and have no cooling. The clutch would only last about 10 mintues at idle speed before it burnt up and released.

You've got a problem in the system which causes the pressure relief valve to open at 400psi. and the restriction is on the liquid (discharge side) So it's blowing R-12 and oil out , which is a fine oily mist.

Now why it's running hot may be due to a bad engine fan clutch. Those do go bad and it'll cause the fan to freewheel when it needs to be engaged for cooling. This could also cause the A/C to build up too much pressure and blow the pressure relief valve as well.

I'd check the fan clutch first by getting it hot and the (engine off) try and spin the fan, if it spins more than 2 times throw a new fan clutch on it and your A/C and overheating problems will go away.

 

[shocker91]

Texan, You hit it right on, thanks. The fan clutch was free spinning all of the time and upon further looking I found the clutch oil all over the inside of the shroud. I lost a little oil and freon but otherwise it looks like the compressor will live to breath another day.