how do i tell if the head gasket is bad or blowen lossing coolant and there is n o sign if leaking that i can find 1995 3000gt the coolant light comes on it just started when the temps fell to -19 when it is above 5 there is no problem and the car overheated once but pulled over right away and stopped car filled the collant and everything was ok now it happened again at -20 and the coolant light came on did not overheat this time added some more to the raditor and reserve tank (or overflow tank) about.50 ozof the permix bottle. My other question is where is the harness for the engine codes in this car. My engine light has not come on however i would like to know whhere it is

 

Posted in your other thread. Please keep it to one.

Thanks

 

Pull your dipstick to see if the oil is "frothy" looking. Also check your passenger side floorboard, in case your heater core is leaking. The coolant has to be going somewhere.

 

something is wrong with your thermometer. I have the same problem and I got it checked out.