intermittent heat?

[sefb222]

not the blower.. it runs just fine.


but, my heat is only working when it feels like it. sometimes it will blow warm air (never hot), but usually it's cold.

clogged line to heater core, perhaps?


maybe an air bubble somewhere in the system?

[jlevie]

Quite possibly air in the cooling system try the following bleed procedure:

1) Using ramps or a jack get the front of the car 1' or more higher than
the rear. That will make the radiator and bleed screw the highest point
on the engine and facilitate removal of air.

2) With the bleed screw open, add coolant until no more air comes out of
the bleed.

3) Leave the filler cap off, or at least loose, and set the heat for max
temp and fan speed. Leaving the cap loose will prevent air that's still
in the system from causing a "coolant fountain" once the engine heats
up. Start the engine and allow it to warm up to operating temp. As it
warms up occasionally crack the bleed screw to release any air and top
up the coolant as necessary.

4) Once the engine is at temp bring it up to 2000-2500 for a few seconds
several times. Then crack the bleed until no more air is released. At
this point the heater should be throwing lots of hot air, which
indicates that the heater core is filled with coolant. You may have to
repeat this a few times to get all the air out.

5) Drive the car a bit, allow it to cool back down, and recheck the
bleed for air. Over the next few days you may get very small amounts (a
few bubbles) of air out of the bleed screw.

[Adrian_Visser]

could be intermittant power to heater valve too couldn't it

[sefb222]

or maybe a bad heater valve?

i guess i should mention that the hvac panel has been out, and reinstalled. perhaps something not hooked up properly?