AC Pressure

[Falcon_LS]

Although ambient temperatures have been quite extreme - 105 - 110 in the evenings and over 120 during the day - the AC on the Envoy isn't quite as efficient as it used to be. I hooked up my gauges and the readings I got were as follows at idle:

Low Pressure Line: 40 PSI
High Pressure Line: 300 - 325 PSI (erratic fluctuation)

The ambient temperature at the time was 108. Does this look like a compressor issue?

 

[ram_man]

Not really. High side is pretty high but with the extreme Temps your dealing with its probably not out of line.

 

[Brad_C]

Depends. Assuming R134a, 300psi is about 116F, so either you have a MEGA efficient condenser or your are probably under charged.

Low pressure is a bit low at 5F, so yeah, probably under charged.

If the compressor was at fault your low pressure would be higher and your high pressure lower. This looks like you're not moving enough volume.

 

[Chris142]

Your high side is a little high. Should be closer to 275. Clean your condenser and radiator with pressurized water. Dont bend the fins. Is the fan clutch hooking up?

 

[Brad_C]

How can the high side be 275psi (110F) if the ambient is hotter than that?

 

[ram_man]

It could be slightly undercharged as mentioned best thing to do is have a shop suck it down and replace it with the correct amount. Or get a gauge set and out a little in till low side is closer to 45 -50 does the envoy have a variable displacement compressor because that'll make a difference in the equation as well.