Heater problems

1994 ford t bird my heater starts hot after a while it starts blowing cold air i can turn the heat up and thats works for a while then it go back to cold if anyone has an ideal whats happening please advise me thanks in advance

This might be a completely different problem, but, like ttaite’s T-bird above, I have a heater problem with my 2000 Mercury Villager (Ford product). I only get hot air through the heater when I’m going over 30 MPH. The faster I go, the more heat I get. The fan runs just fine and normally.
Any insight would be gratefully received.

Usually if your antifreeze is full and there isn’t an air pocket problem, then it is usually a plugged heater core issue. If you’ve ever used some of the stop leak or other radiator leaking product in the past, that stuff is pretty good at plugging up heater cores.

I think that the 94 had automatic climate control (if not, it had semi-automatic climate control). It could be a temperature sensor issue. Make sure that the little air hose that goes to the interior temperature sensor is correctly connected and not blocked in any way. It’s job is to suck interior air past the sensor.

It sounds like there’s trapped air in the cooling system. To determine if this is what’s causing your problem, try this.

Get the engine up to operating temperature. With the engine idling, slightly loosen the upper radiator hose clamp. Take a small flat bladed screwdriver and slip this between the upper radiator hose and the radiator hose neck. Allow the engine to idle until there’s no more spittin’ n sputterin’ of air escaping from the cooling system to where nothing but coolant comes out of the upper radiator hose. Remove the screwdriver and retighten the hose clamp.

Tester

MOST grateful for the suggestions. I will check each one out after the sun comes up tomorrow.
Although shivering should be good exercise. I’d rather go to the gym.

You also could have a worn impeller on the water pump. At low speeds it wouldn’t be able to pump much coolant, at high speeds it’s adequate. In fact I know someone with a Taurus who had that very problem.