The ac had been working fine or better ... freezing me out. then the other day it went from ice cold to cold then nothing then back to cold, back and forth in just seconds. then just unconditioned air. I turned the temp dial a bit warmer and back to cold and ac came back on for a bit. when I got home I opened the hood and can hear the clutch engaging and disengaging every few seconds. I check the 134a it was right where it needs to be. while sitting in the driveway with the car running and ac on temp was 180. new dex cool about 1.5 years ago. when out for a ride ac cold but I think the compressor was still cycling. so something is going on and I'm going on a 650-mile trip and don't want it to crap out on the way. any ideas?

Thanks Scott

09 2.2l

 

Could be the pressure switch, about $58. Could be the clutch is bad, most replace the entire compressor. Could be the blend door.

Could be lots of things, a pro could tell you.

The temp dial just adds hot air to the mix via the blend door, it doesn't do anything to the compressor.

 

Without posting the high/low readings of the refrigerant, that statement above doesn't help. How did you check it ?
Could be just about anything as Donbrew suggested.

Fwiw. A compressor engaging/disengaging every few seconds is usually the result of low refrigerant.

 

Fwiw. A compressor engaging/disengaging every few seconds is usually the result of low refrigerant.

That's what I thought so I put the bottle on with the gauge to add 134a when it's low and the low pressure was in range. I had a similar issue my Silverado and I just added some 134 to it and it works great.
The thing with the temp change maybe just a coincidence. After doing a lot of reading on here I was leaning towards the pressure switch. is there a way to check the switch? If I change the switch do I have to evac the system or is there a schrader valve behind the switch like most?

https://www.chevyhhr.net/forums/prob...-change-58987/
just finished reading this looks like I'll start here

 

well that didn't work changing the pressure switch

 

OK I got a set of gauges and something is wrong. I hooked them up and without starting the engine low and high sides are around 115psi. when I start the engine the high side goes to just under 200psi and the low side needle gets pinned to the high side of the gauge.
what's going on here? compressor, valve, orifice tube?
thanks

 

http://www.aa1car.com/library/ac_diagnosis_chart.gif

 

got it fixed,
was an overcharged system. don't know why but that seems to be it. a good source of info is this also Troubleshooting with Gauges FAQ

 

They don't get over charged by themselves.

 

Overcharged ?
If that's true, then there's something amiss with the given info since post #1.
Going from cooling and working good ("freezing me out") in post #1 to having problems. So at what point did it get overcharged ? Like Don stated, "They don't get over charged by themselves."