Automotive Air Conditioning Information Forum (Archives)

Provided by

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

350 psi low side pressure

erasable on Thu June 09, 2011 11:43 PM User is offlineView users profile

Year: 01
Make: oldsmobile
Model: intrigue
Engine Size: 3.5
Refrigerant Type: 134
Ambient Temp: 93F
Pressure Low: 350
Pressure High: 175
Country of Origin: United States

Hi everyone, its a little embarassing since I work as a mechanic, but this car got me stumped. Theoretically, I can just replace everything, but I try not to be a part swapper, I try to do the right thing.

So the 2001 Olds Intrigue 3.5L came in with a no ac complaint. I recovered the 134 and found it to be a little low. Its supposed to have 35 oz., and it had about 28 oz. So I put it under vacuum and found no leaks. Recharged it, compressor kicks on and low pressure sky rockets! It hits about 325 on the low side and the compressor never cycles off. As soon as I shut the ac off it maxes out the gauge on the machine to 350. High side seems to be normal though.

Any help would be much appreciated. Also all readings and charging was done on a SnapOn ac machine, no cans.

GM Tech on Fri June 10, 2011 12:16 AM User is offline

Low side guage wont read that high- is scaled seperately-- but I do believe you are pegged- so that is a firm indicator of air in the system- Your refrigerant tank on your scale has air in it--your air bleeder vent is probably not working due to valve depressor not being depressed because you have the air hose on backwards-- check it out- it could happen to anyone who is not careful and understands their equipment.

The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

erasable on Fri June 10, 2011 3:25 AM User is offlineView users profile

Hi thanks for responding. On my snap on kool kare plus machine, the low side gauge does go up to 350. And what air hose are you referring to? The only hoses I've touched on the machine have been the ones that attach to the service ports. And also the machine worked fine on another car after this one. But I will have the snap on guy take a look at it anyway. So pressure situation aside, what would keep the compressor to never cycle off and still have no cold air?

NickD on Fri June 10, 2011 8:16 AM User is offline

Can only visualize the orifice is solidly blocked, but can't even visualize why the low side is greater than the high side. Not easy to reverse the lines to R-134a ports, but never really tried to.

iceman2555 on Fri June 10, 2011 11:30 PM User is offlineView users profile

The opinoin expressed by GM is a valid one. Test the refrigerant with a refrigerant ID'er to determine the presence of air. Also this vehicle utilized the 'new design' orifice tube. Have seen these things become highly restricted. The small 'glass' beads are the filter and the orificing section of the unit. They can become more easily contaminated that the 'standard' GM type orifice

This iimage is from a unit removed from a late model GM with app 100k miles. The compressor (V series) was operational but clutch had begun to indicate possible heat issues (extra head pressures).

The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.