Well... Not really a problem but I was wondering about what the cause could be.

When I warm up my car and turn on the heater, it doesnt blow hot air. but when i start driving it blows out hot air. Then when I stop it begins to go cold. Any reasons why this might be?

 

Low on colant/ air in your system.

 

I changed the thermostat to get hot air. My symptoms were that sitting with the engine running, I would get semi-hot air but if I drove anywhere, the temp would drop quickly. You could watch the teperature guage drop as I drove. The thermostat was frozen open. I changed it and it has worked perfectly.

One other thing to look at would be the Heater contrrol valve. It's symptoms are slightly different. If it is that valve, you can test it by reversing the two vacuun lines that go to it. B-T-W: the value is up near the fire wall on the left side of the engine (As you look at the engine from the fromt - on the driver's side.) Replacing that is expensive, I got a used one from a salvage yard for $100.00.

Try the Thermostat first, it is much less expensive

 

So possibly if i just bleed out some air, that might fix my problem?