Ok my Suby is overheating when I'm driving and have my heater on for some reason. This is very weird cuz usually an engine SHOULDN'T overheat when the heater is being used...?.? What is up? Thermostat?

Mine 'appears' to overheat when I have the heat on. Or more precisely, when the blower motor is cranked up. Its been a common issue on a few of my subarus now. Its more of a ground problem than a cooling problem. I installed an aftermarket temp gauge and a 2 core radiator and all is well.. Stock gauge still shoots off the charts when I crank the heat up though.

So its normal? Do you think the temp sensor needs replacing or cleaning the connections? Is it located right on top of the thermostat?

So its normal?

 

 

Maybe, but I would still hunt down the problem or put an aftermarket gauge on there to be sure. Stock gauges suck:-p

Ya I see that. Seems like it overheats only sometimes... crazy. Thanks.

they other reason it could be overheating with the heater on is subarus ac pump kicks on with the heater also

they other reason it could be overheating with the heater on is subarus ac pump kicks on with the heater also

 

Mine only kicks on when the AC or defrost is on.

Do you have one or two pins coming out of the temp sensor? If only one pin, the circuit is depending on a proper ground return and that might be missing. Same thing happens on the temp switch to the fan if there's only one pin; the little grounding wire for the radiator is gone and the fan doesn't work because it too needs a ground to work properly.

So the temp sensor on top of the thermostat housing? Two pins as in two wires coming out from the top of it or what? I'll check.

Also if I do get a new thermostat, how hot should it open up at??

Thanks.