I have a 1996 Honda civic ex and it only gets hot when ideling as soon as I take off it goes back to normal. The temp. gauge has not went into the red but it gets close. I have changed the radiator, thermostat, and two new hoses. I have also checked the system with the tube and blue liquid to see if maybe a cracked/blown head gasket test showed all to be good. There is no coolant in oil and no white smoke.

 

Is your radiator fan coming on?

 

Yes fan comes on

 

Well then I'm stumped. Temps should drop as soon as the fan comes on.

Unless...Have you bled the coolant, and are you sure its topped off?

 

Hard to say but my guess is bad water pump... See if it leak, also make sure you bleed your system using the bleeder screw on the upper radiator hoes at the block.
When bleeding have your heater switch set to HOT position to allow coolant to flow in to your heating core.

 

Please also check your radiator fan. sometimes the fan not spinning fast enough.