Heater problem.

[pulsharc]

My heater is blowing cold air at idle and low rpms. The engine temp is getting to normal temp just fine and staying there, so the thermostat should be fine(just replaced it a year ago). If I rev. it up to about 3000rpms at a stop light it will blow hot and it is fine when cruising as long as the rpms are above about 2500 rpms. The service manual's "heater and A/C" section is all A/C with no info on the heater so that didn't help. Any suggestions?

[s13sr20chris]

bro, you have air in the system. with engine cold, jack up the front end, removed radiator cap, and remove bleeder screw. top off fluid till it pours out of screw. reinstall screw and run engine like that topping off fluid the whole time.

[pulsharc]

Thanks, I'll try that this weekend cause the head snapped off the bleeder screw so it needs to be extracted and replaced before I bleed the system.

[yellow_jacket]

If bleeding it doesn't work, then there is a blockage in the coolant path. Usually it is in the actual heater core itself.