Rep Power: 0

Hi,

I have a 95 honda civic EX that is currently overheating. I've determined that this is caused by the radiator cooling fan not turning on. I've done some simple diagnostics i.e. hooked up cooling fan to battery to see if it turns on, replaced the cooling fan relay, and everything seems fine. The only thing (I think) left to replace that can cause the fan to not turn on is the coolant temperature switch.

Is replacing the switch a do it yourself project?

I see that it is located in a very accessible position (right on top attached to the thermostat housing). I am guessing all I need to do is remove the plug, unscrew the switch, screw on the new coolant temperature switch, and then re-attach the plug. Is this accurate? Will coolant leak out of the thermostat housing if I unscrew the switch?

Thanks. Note that I am pretty noob when it comes to cars, but I don't want to put any more money into my car so anything I can do myself I would like to

 
Rep Power: 812

dont forget there are two sensors. one is the ECT (engine coolant temp) and the other is the fan temp sensor. both are located near the thermostat in the coolant passage. they are easy to remove with a wrench or a deep socket. for the ect, usually the one sticking up, you can take it out no problem. the fan sensor is pointing down and you need to drain some of the coolant first. if your fan doesnt work, then you want to replace the fan temp sensor and not the ECT.

also are you sure the only problem is the fan? usually fans are only useful in preventing overheating if the car is in stop and go traffic and the outside temp is 85F+ degrees.

 
Rep Power: 0

Thanks GearBox. I looked at the thermostat housing for my 95 civic and I only see one thing sticking out (besides the ground screw attached to it). I can check again when I get home. Does someone have a picture maybe that they can show me? Is it possible that my ECT is located somewhere else?

The reason I think it is my cooling fan is that my car only overheats when it is idle. I drive a lot of freeway mileage and it is only when I get off the freeway that it starts to overheat. Lately, to prevent it from overheating, I just blast on the heater to cool it off but now temperatures outside are getting 95+ which is making turning on the heater unbearable. Note that there are no coolant leaks. I check underneath my car and it is clean. Also, the coolant levels stay full.

What is also interesting, is that it only overheats after being on the freeway for 30+ minutes. If I sit out in front of my house and rev the engine with the AC on, it doesn't overheat.

 
Rep Power: 812

freeway driving will heat up the engine way hotter than sitting in a driveway tho. lemme see if i can find the fan switch for your car. hmm i cant find it either. so you only have one sensor in the cooling passages? its possible maybe it does both functions but im pretty sure its a separate sensor for the fan. did you trace the lower radiator hose to the back of the engine and look for a sensor there? i think thats the ECT and the fan sensor is in the front?

 
Rep Power: 812

found this too

http://www.honda-tech.com/showthread.php?t=2571707

 
Rep Power: 812

and.

http://www.clubcivic.com/board/showthread.php?t=176865