problems with overheating....kinda

[gwoodtitansz28]

I flushed out my heater core to restore my heat. But after i did that i had heat but the car kept overheating. It definately overheated cuz coolant spewed out of the resevoir cap. I may have fixed that by bleeding it several times since then. I replaced the thermostat. My gauge still says its running really hot but i borrowed an infared thermometer gun thing and according to that the thermostat housing is staying around 180-190 when the thermostat opens. So I wonder if the gauge or sending unit is bad. Anyone have any insight to this problem?

[chevymec]

It could still have air in it. If the air is right at the sensor it will read wrong. If you open the bleeder does water start to come out right then?

[gwoodtitansz28]

Ya the last like 5 times only water has come out. Im gonna keep bleeding it for a few days. I may go ahead and swap the sending unit out but it sounds like its hard to get to. But atleast it seems to be staying cool so the gauge not working isnt as bad of a problem to have. Anything i can try to rule out the sending unit before i tear into it?

[Chris]

Disconnect the plug from the sensor and jump the terminals. The gauge should go all the way to hot. With it unplugged it should be all the way cold

[gwoodtitansz28]

ok ill look into that when i get a chance. thanks.

[JAKEJR]

When doing a manual bleed, I always, after placing several layers of wash cloths over the OPTI, open the bleed screw (with the engine off course), and let it bleed until I'm absolutely SURE no air bubbles accompany the coolant as if flows out from around the bleed screw.

I DON'T close the bleed screw as soon as I see coolant flowing out, I wait until it flows freely with NO air bubbles.

I then top off the surge tank and replace the pressure cap. Works for me.

Jake

[gwoodtitansz28]

ya thats how i bleed it too except i let it run. but it never gets all the air out the first time for me.

[popo8]

If you have access to a scan tool... most of them will tell you ACTUAL motor temp which you can compare to your guage.... just in case.