Another A/C Question

[SS Crew]

I was at the at the Colorado River in the Arizona desert this weekend. When we were getting ready to leave after putting the boat back in the storage. I had the truck idling in 120 degree heat for about 5 to 10 minutes to cool down the cab. When we took off, after 30 seconds, a pressurized hiss sounded and then stopped after about 5 to 7 seconds. When it stopped, it sounded like a valve closed, that quick and sudden.

 

Driving to home through the 200 plus miles of 110 degree heat, the air comming out of the vents was not real cool. Well, it was cool, but not really cool, boarding on cold like is in the not so hot areas. It took almost 2 hours for the recirc to turn off. Oh btw, I had the auto air set to 72 degrees.

 

This hissing has happened before, last year, also when I was idling. I took it to my Chevy dealer and they replaced the A/C compressor because the low pressure side was too reading too high. At least that's what they told me. It has never cooled like it did when it was new.

 

Why does this happen? What do you suggest I say to the dealer when I take it in?

[GM-Tech]

Dunno what sound you're hearing. What kind of temperatures are you expecting out the vents at 110-120 ambient temperatures? The vent temp should be at least 20 degrees cooler than ambient, though in reality they're usually much cooler. So at 110 degrees, that'd be 90 degrees out of the vents.

 

I wouldn't expect icy cold air when it's 110 degrees outside.