Nissan Altima

I Have a 2004 Nissan Alitma SE, 30K miles.

The heater only puts out heat when I have been driving maybe 30-45 mph without stopping, for a at least a few minutes.

Once I stop, it goes back to cold air, even if I have been driving for hours.

Basically, the heat only works while the car is moving for 5 minutes or more.
January 26, 2007.

What is the level of your coolant. Low level will do that.

Its sounds like another case of a whacko thermostat-remove the Stat and check for an increase in heat. If so you have found your bad friend-staying open. Replace

And again it might be an improperly mixed coolant that is freezing up or a partial clogged radiator and the list goes on.

HTH Good Luck!

Jan 27, 2007.
Yeah, you're right, just startin with the baics : )