On 90+* weather, if I have the AC on while I'm crusing around, the coolant temperature will creep up past 210*. The AC will blow cold air until I shut it off.

If I don't give the car a few hours to cool after being that hot, when I get back in the car, start it up, it will only blow hot air. It doesn't matter how long it's been off, 5 minutes or 30 minutes, still hot air. If I give it 3 hours or so, it'll pump out cold air as normal.

Any guesses? Thanks!

 

This may be basic and you may have already eliminated it, but just in case are your fans running?

 

i'm having the same problem in my 94 1500 chevy truck. my dad is an ase gm tech. he said -mine- is due to a freon leak, and the freon leak is making my "xxx" get too cold and is freezing it so it can't turn. therefor the hot air.