Outlook / Traverse / Acadia / Enclave A/C problems

[lanxer57]

The outlook shares most of its mechanical parts with the chevrolet traverse, gmc acadia, and buick enclave. This seems to include the A/C system. My mother drives a Traverse. I am already on this forum, and am too lazy to join a traverse forum. I recorded a video of testing the air conditioning system with a manifold gauge at an ambient temperature of about 90 F, and spraying the condensor with a hose. https://youtu.be/P1nV8IO4Xww
The cooling fans seem to be working at both speeds. The compressor cycles on and off every few seconds after the vehicle is started, the needles on the gauges oscillate with the compressor. It does this for a few minutes or so before shutting off entirely, this is why I manually overrode the compressor, forcing it to run constantly. Even with the compressor running constantly, The high side pressure is too low, and the low side pressure is too high. spraying the condenser with a hose seems to help this pressure difference a little bit, but not enough. I tried evacuating all of the refrigerant from the system, and then left it, and it held vacuum steadily, I also did not see any residue from leaking refrigerant with a UV light, after refilling it, it continued to act in exactly the same way. The A/C seems to work fine when the vehicle is in motion, I initially thought that it was related to airflow, but I now believe it is related to engine RPM, as revving the engine for a few seconds seems to make it work better, and correct the pressure readings. Also, The compressor sounds a bit like a diesel engine, I did not listen very closely after replacing it a few years ago, Is it supposed to sound like that? I suspect that the compressor may have failed again, Any ideas?