I just got a 95 gsr put into my 90 integra. for some reason i only start to overheat when its cold outside and i dont have my heater on. my radiator is topped off and i just installed a new thermostat. if you have any advice or idea what is going on please let me know at antiheroskater50@hotmail.com thank you very very much

 

check your timming.....
make sure everything is at is point...

 

did this start happening after you installed the thermostat? Did you bleed the coolant system while you were putting in the coolant?

 

no it happened once my swap was complete. i changed the thermostat but it didnt help....

 

Sounds like you have air in the system that came in when you the motor you swapped in was removed..

open the bleeder valve...