Check the radiator fan. The only reason i say that is b/c the car overheated when the car was stopped at a light. The rad fan is suppose to cool down the radiator when air is not passing over it (like stopped at a stop light). If the fan is notspinning, check to see if there is power to the fan. If there is no power to the fan then you will have to examine thecircuit forpossible problems. If there is power to the fan, most likely the fanmotor is burned out. This can be confirmed by a resistance check on thefan.It is not needed while the car is moving at higher speeds. Also, check the thermostat since you car is not heating up properly. Does the car have heat? The thermostat could be stuck open which would cause the fluid to be cooler than usual.

 

Agent, why do you think this car is not heating properly? Slightly below horisontal is where the temp guage normally was on almost all of the cars I ever drove.
And I second you on radiator fan intermittent problem. I don't think thermostat has anything to do with this particular case.

 

I didn't think that the guage was slightly below the middle, i thought it was signficantly below the middle. I've never really busted out a ruler to check how far down 1/4in is on the guage. If its only slightly below the middle, then the thermostat is probably not the culprit.

 

I bought a 94 honda civic, when the car is in park it does not overheat at all but when i start driving the temperature gauge starts going all the way up within a few minutes, in order to go down i have to turn on the heater on max then the temperature gauge goes down again. I HAVE REPLACED THE WATER PUMP, THERMOSTAT AND TEMPERATURE SENSOR. The fan works ok. i don't understant why does the temperature gauge goes all the way up. When i open the hood i don't see any sign of overheating, it seens like it have right temperature, coolant is not boiling, i bleeded the coolant system. What else can i do? What seens to be the problem? Why do i have to turn on the heater in order for the temp gauge to go down?.....someone told me that the head gasket could have a leak, but no smoke comes out the muffler nor i see any leaks coming from headgasket......i have also put in one of those block seals liquid into the radiator with water, i followed the instructions......

 

You radiator is clogged - when you turn the heat on and circulate the hot coolant through it, it's working the same way the radiator's supposed to.

Time for a new radiator if you can't get by with the sealer anymore.