hey guys im having an issue with my car (1996 honda civic ex) overheating. i just swapped out the motor and insatlled a dx motor, tranny and what not to get better gas mileage thant the old vtec setup. For some reason now when i drive on the highway my car overheats. When i am driving it around town it doesnt overheat. I dont know if it has to do iwth my car throwing the cod p1298 (WHICH I STILL NEED TO FIX), Or what else it could be. i bled the system and i keep filling up the overflow and it keeps getting sucked away.
any ideas?

 

Did you actually fill up the rad as oppose to the overflow?

 

You should be filling up the radiator, not the overflow bottle . . .