I have a 04 SS 3.8 monte carlo and I'm have troubling with figuring out why the heater isn't working correctly. Last year the heater cord went out and it was replaced. Everything was working fine for the rest of the winter. The weather has changed and I turned my heater on this year and its not blowing hot air. I thought it might be the thermostat but that's working fine. Can you guys give me some ideas as to why its not working correctly?

 

Heater core sounds like its out, thats what creates hot air and the blower motor blows it inside the car.

 

There could also be an Air pocket in the system....
Or if you didnt do a through flush before you instahled the new heatercore...it could be plugged up again...

R u sure your fluid level in the radiator correct?

Do you have the correct mixture of antifreeze and water?

Are you sure that your system is even flowing (open and closeing of the thermostat)...Is it running hot?...Is the water pump working?

Maybe, Try flushing the system throughly?....

 

Ill check it out. The heater cord was replaced last year and everything was running fine. Thank you for the ideas