ok, having a small problem with my car. for example, once my car gets warmed up and the heat is blowing hot, if i come to a stop light, the air blows cold the whole time i'm at the light, and then once the light turns green and i take off, within 5 seconds, the air is hot again. and i mean the air gets real cold. what could this be?

 

check your coolant level

 

Low coolant level will not make the AC unit blow cold air at idle. A busted radiator hose will cause your AC to blow hot air however...

 

you have air in your coolant system...same thing happened to me. you need to get it burped or do it yourself if you have the means to do so.

 

i had a problem with no heat. It seemed to just work on and off. Well i filled my coolant up and i immediately had heat again. Thats why i gave you that recommendation.

but vo7848 could be right. there is many different things that could cause your problem. GL

 

Um, where did you see AC in the OP? And yes, low coolant level WILL result in no heat at idle - my top hose was leaking a bit after replacement and it happened to me. Filled it up and Voila! had heat at all speeds. Air bubble can give the same problem - open the bleeder in front of the battery while the car is running and warmed up to bleed. Normally coolant has to get pretty low before you get an air bubble though.

 

I have the same issue now. I also had the same issue in my 323i. Just figured it was normal.

 

thank you everyone for your responses. as soon as i get off of work, i'm gonna check my coolant level and go from there.

 

My bad, I read the post incorrect...