Thread: PLEASE HELP - Heating Issue

Hey Everyone,

I have a 2004 Grand Prix and for the past several years, when the weather gets warm after winter, the car will continue to blow HOT air only for several weeks, sometimes into May before going back to normal and blowing cool air. This happens every year and there is no real rhyme or reason for it. I have flushed the coolant and replace the thermostat. I have charged the A/C but issue still happens. GM cannot seem to fine an issue. As I stated, the issue rectifies itself after several weeks of warm weather but just wanted to see if anyone else has had an issue like this? It's annoying driving in 20C weather and having hot air blowing on you. I thought maybe the trap door was stuck but it fixes itserlf on it's own so I am at a loss?

Derek

Sounds like a blend door issue. Maybe something in the HVAC head itself. Those are the only places I could think of that could cause it to "stick" in one mode or another.

Thanks Fordman77, That's what I was thinking , just seems odd that it rectifies itself after several weeks of warm weather then is fine for the Summer. Once I switch it over to heat for the Winter, it seems to get stuck there until usually around May. Weird.

Actually I've noticed that even my 3-knob single zone climate control in the 00 GT gets stiff on the heat/cool setting when I turn the knob to adjust when it's cold out. Now that it's warm it turns with ease. I think the rubber seals for the vacuum must not like the temp changes and cause it to hang up. Maybe try lubing the blend door actuators (if you can get to them).