Help diagnosing AC

[sylvainm]

I've got a 2011 Aveo LT, AC is only cooling about 10F from ambient. I've evacuated it and it held vacuum. I refilled it using around 500g of R134a. on my gauges I get around 54psi on low side, 180 on high. Outside temps were around 78F and vent temp went to around 68F. Radiator fan only kicked on when engine temp got high from idling.
Pressure switch seems to work properly
AC Clutch turned on and off with pressing on/off the AC button or pulling out the AC relay under the hood
BUT one thing I noticed is that it doesn't seem to put any load on the engine. On other cars, when AC clutch latches you can feel/hear the engine load increase and trying to compensate.
I suspect the compressor is bad or the control valve in the compressor is faulty. because of the no load while the AC is engaged. I'm at the point where I might buy a new compressor, a new expansion vale and a seal kit to replace all of them while I've got it all opened up.

[Deano]

Sounds very familiar. Just like my situation. My AC died on my 2009 Aveo back in 2020. I replaced the expansion valve, evacuated it, it held vacuum, then i recharged with R134a too. Didn't help. After Googling around, i concluded that the pressure/control valve inside the compressor was the probable culprit. Ordered a new chinese compressor (UAC) from RockAuto, installed it, evacuated again, recharged again with R134a, and it was working perfectly again. Still working today.

Deano

[Eg.h2o]

Another thing to look at, when you have the ac on, the cooling fans should also be on (at low speed).

[sylvainm]

Well I replaced the compressor and the AC now works. I had a hard time finding how much to R134 to add. The sticker for that info is gone under the hood. I found online a mention of 500g. So I did that much. I think I need to add a bit more. The pressures were in line for outside temps when I filled it but it takes 2-3 minutes for the AC to spit out cold air but when it's cold it's going to 50-60F outlet temps

[Eg.h2o]

Glad you got it fixed!