I got a 2001 honda civic Lx.The NY weather been cool lately @ night so i turn on the heater and my car starts to warm up.2 weeks ago when it was hot out i turn on ac same thing.3 month ago i change Water Pump and Thermo stat new radiator and radiator cap.temp sensor also.Both fans power also.So can it be a bad head gaskit?

 

Is the antifreeze full? Did you bleed the air out of the system?

 

yea we did that test and it has coolant also.like i cant turn on ac or heat or defrost like it has to be off or the car will overheat