ok.

so here it is. I was on the long road trip home(about 4 hour drive) and my car was getting high temp reading. turned on the heat and the temp dropped down. so okay, sounds like a themostat. So i found the local auto parts store and changed it out in the parking lot. I let it idle, i drove it around, went through the drive thru at the Mcd's and idled while I ate. it was good. got back on the interstate and it started getting hot again! when I am in town, its fine, i can idle for a half hour with the AC on and its fine, but the intersate is a no go, ANYONE ever heard of this or know what it could be?

I don't think it's a head gasket, no oil in coolent/coolent in oil.


help!

 

Water pump.

 

what kind of car?

 

A friend had this happen. It was the radiator. It was clogged and corroded. Coolant flowed enough at idle to keep it cool, but under load, it would underflow and over heat.

 

yes, clean your radiator

 

is the fan coming on?

 

radiator

 

X2 radiator