Originally Posted by andrewwynn

@ oh: used to use the heater to try to keep the engine cooler, especially caught in traffic with my previous car (Z28 Camaro convertible), but there wasn't enough BTU transferred with the heater core even venting to outside with the top down and the heat on max (and that was tremendous: I think the Camaro which had a 5.7L V8, shared some HVAC parts with the suburban!

Anyhow in desperation, as my shoes were literally getting soft from the insane heat I switched to full AC "just for a minute" and I was shocked beyond words when my engine temp dropped from the red zone to normal in under two minutes.

Clearly the different programming of when the electric fan kicked on was a much lower temp and it worked perfectly. From then on no matter what temp outside (down to maybe 30/40F, I always use AC when in traffic to keep the engine temp down (ironic I know).

I would be very interested to know if running the AC will chill your car going up hills using the electric fan by turning the AC on. (maybe you already tried and know if it works).

My first car didn't have a big motor and was progwmmed to turn off the AC on full throttle. I noticed often on long steep hill climbs it would slowly get warmer until I created the hill and the AC came back on.