i know the oem thermostats operating temp. is at 180 F but i recently replaced it w/ an 170 F, but instead of staying at 170 F at normal operating temp, it goes up to 185 F or so...can this be a defective thermostat? btw when i installed the new one i did notice that it wasn't a tight fit as the original one but i don't think that would be the problem. i can tell the temp b/c i have a Autometer temp. sensor sandwiched between the radiator hose.

 

If your cooling system is not efficient enough to run at the temperature the thermostat opens at, then it will not stay at that temperature. If you increased the cooling system's effectiveness a good bit then you could get it to plateau at around the stat's opening temp.

 

ok problem solved. damn Autozone employee ordered me the oem temp. one instead of the 170 degree. all good now.