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Compressor engaging but not building pressure

itjstagame on Fri May 18, 2012 5:40 PM User is offline

Year: 1997
Make: Saturn
Model: SW2
Engine Size: 1.9
Refrigerant Type: 134a
Ambient Temp: 88
Pressure Low: 75
Pressure High: 75
Country of Origin: United States

Hello all,

I have a '97 Saturn that I have owned for about 8 months. When I got it, the condenser was missing and a piece of the condenser was still screwed in to the line (and would not come out), so I got that one piece of line and a condenser from a junkyard and bought a vacuum pump. I know I've been exposed to air for a long while, so I pulled vacuum for 2 hours and then left it off for an hour to see if I held vacuum. Everything looked good.

I should also mention, I looked up and found that my compressor likes PAG 100, so I put .2oz in the condenser (read on another forum that that is a good idea when replacing a condenser). Then I added 1 can of R-134a through the charging port of my manifold gauges (actually through the T on the vacuum pump). Pressures went up to 75psi.

I tried starting the car and turning on the AC and the compressor will kick on and run continuously (didn't see it kick off during a 5 minute idle).

I noticed though that the low side (the only side hooked on during evacuation) stayed at 75 even with the compressor running. So I hooked up the high side and it was at 75psi too. I am positive that the compressor is kicked on and running.

I noticed too that the compressor is making a sort of tinny noise, sounds a bit like an air compressor after its hot and been running a while, kind of like it has a rattle.

So the question is, is there any chance that too low of a charge or too low of an oil (maybe I should have added more?) could cause a compressor to not build pressure? Or is the only cause of no pressure change with a running compressor a bad compressor?

I am completely new to this and may have to replace the compressor anyway because after all of this and holding vacuum and charge and etc, I unhooked the low side and it is leaking from the charge port. I tried rehooking the manifold hose and not and playing with it but it would not seal. That line in particular seems to be part of/hooked directly to the compressor (no bolt, runs right in to the back of it). So maybe that was the issue unrelated to the missing condenser.

Who knows, any insight is welcomed, thank you.

JJM on Sat May 19, 2012 2:10 PM User is offline

Check that those stupid R-134a low-loss port adapters are wide open. If they are, and the compressor clutch is engaged, and high and low side pressures are not moving, most likely the compressor crankshaft is broken. I've seem this on a few Ford compressors, but check the port adapters on your gauge set first.


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