Heater Not Working Options

[Stu37363]

My heater used to work great...

Now the air it blows is cold-room temperature at best

if i turn it off for a minute and turn it back on i get hot air for a second and then it goes cold again...

any ideas? possible causes and solutions?

[Bitter]

you probably still have air trapped in the system, specifically the heater core.

take the radiator cap off, turn the knob to full hot, put it on th vents, turn the fan speed to low.
start the car and let it idle, it'll push out some coolant don't worry.
keep it idling until both radiator hoses are HOT, one will stay cold for a while and one will get warm faster, the cold one is the one you're waiting for, it'll get as hot as the other one with the thermostat opens. by now your heat should be wamr

once the thermostat opens your coolant level will probably drop in the radiator and it'll bubble some air out, refill the radiator to the neck and put the cap on and continue idling the car, by now your heat should be hot. let it idle until the radiator cooling fan comes on and then goes back off. turn the engine off and let the car cool down for 2-4 hours, make sure the coolant reservoir is full, as it will draw some coolant in. after its cooled go re-check the reservoir and add coolant as needed, put it slightly above the hot level.

start the car and let it warm up then go for a spirited drive with the heat on, some additional air may purge from the system so keep an eye on the temp gauge. again, let the car cool and recheck the coolant level.

your heat should be hot, your cooling system free of air, and your car should be much more enjoyable.










now, for hecks sake this is the 3rd of 4th time i've posted how to do this, can someone make a sticky?