Hey everyone, sorry if this is in the wrong section!

I just got an '06 Monte Carlo LT, and I have noticed that when using the heat, the blower works fine, however the air will not get warm unless the car has been running for a while and usually never when idling.

AC works fine however.

I have seen some similar stories on here but can't seem to find a solution. I have heard it could be the thermostat, is that the true?

 

Yes it could be the thermostat, could also be air stuck in the system, but I don't believe your car has a proper bleeder valve

 

Mine doesn't blow warm air unless the RPMs are above 1500 or so. I also hear a gurgling noise from the dash. I think it's what chibi said, air stuck in the system.

If you let the can run until the temp gauge hits normal, then rev the engine up to 2k or so, does the air suddenly turn warm?