When sitting still, at idle, the A/C will only cool to about 8-10f degrees below ambient temp at 100f. Vent air temperature will climb from 42 to 90 degrees f at a rate of about 1 degree per 5 seconds when set on max fan speed and non-rec, setting rec slows the temp increase by about 3-4 times. Pressure on low and high side go up and off the gauge when this happens.
At 1500rpm, sitting still, no problem, gauge readings are like 26/240, vent temp is 40-44f and the compressor cycles regularly, even at 103 ambient. I can coast down a very long hill for 30+ minutes at 15-30mph speeds with the engine in neutral, and maintain normal operation. So airflow over the condenser anywhere above idle speed from the radiator fan is enough.
These would lead me to suspect the fan clutch, however coolant temp never varies significantly (actual reading from Techstream, not the idiot gauge on the dash). I also can't stop the radiator fan when coolant temp is at operating temperature.
I have evacuated/charged and pulled vacuum between on the system twice, no change in operation or readings. It also held vacuum for over 12 hours, so no leaks.
Magnetic clutch on the compressor operates normally and all of the techstream active tests produce expected results, no stored codes.
I am pretty ignorant of cooling systems and am at a loss at this point. Hoping to avoid throwing parts at it until I find a fix, as many of these components are not cheap nor quick/easy to install.
