I have a 1995 honda civic dx. But it has a motor swap with a 1996 honda civic 1.6 non vetec mfi. The car does fine driving around town but as soon as u get on the free way the temperature goes up. And every once in awhile the temperature jumps up a little and goes back down. If you turn the air conditioner on it goes up a tiny bit and same with the heater. The heater doesn't blow hot air just barley warm. We changed the thermostat. It was messed up when we took it out. Put a new one in and test drove it and same problem. Not sure if it would be something like the radiator. Please help.

 

You need to verify if the fans are turning on when the car is overheating.

 

Yes they are.

 

Radiator, coolant level, water pump, system leak, plugged lines, collapsed hose, etc... many different issues it could be. You need to actually take the time to start diagnosing things so you can relay information so we can actually help you.

 

You need to bleed the coolant system, sounds like you have air in the system. 94