I just wanted to know Since I change my thermostat my coolant temp is really cool it take about 15 to 20 min of driving before it reach close too but not quite the middle of the oem gauge. But when on the highway the temperature drop close to C. I get off the highway and standing at the red light the idle is at about 1400 to 1600. Is this gone to hurt my engine ??? But when driving The engine feel alot more stronger than before!

 

sounds like the thermostat is stuck open dude. so coolant is constantly flowing through the radiator and not reaching the proper operating temperature

 

my old thermostat was stuck open and it was over heating not giving the coolant a chance to cool down! I check the new thermostat no more over heating. It eiter close or open!

 

if the thermostat is stuck open, the car will not warm up

 

^^^which is exactly what happening to him...

 

right but hes saying that his old one was stuck open and his car would overheat. if its stuck open the car wont overheat

 

never heard of a car overheating with a thermostat stuck in the open position.

 

As everyone else has said if your thermostat housing was stuck open you car wouldnt overheat but rather say extremely cool. The fact that you replaced the thermostat housing and are still having problems leads me to believe that you have some other issue.

Where is the coolant temperature probe located? Something leads me to believe that is whats faulty thus its giving your car false readings...

 

when you were overheating your thermostat probably wasnt opening at all, now its stuck open so your stuck in cold start and not reaching operating temp.