Q. Just wanted to say thanks for all the helpful hints you give. I have a 1994 Honda Civic LX, 1.5 liter 4 cylinder and automatic transmission. Odometer reads 155,000. Lately the temperature gauge is fluctuating a lot. I noticed it when I am on the highway. When there is heavy traffic and I am not moving much it gets hot.
Honda Civic Temperature Fluctuates
When traffic loosens and I go it cools off. I don't have a leak and I changed my water pump in December 2003. Any ideas you can give would be greatly appreciated. I was thinking it was the thermostat, But you would know better.
A. This is a classic symptom of an inoperative electric cooling fan. When you are moving, air comes in and flows through the radiator, cooling it down. When you are stopped, no air flows through the radiator and thus no cooling takes place.
To confirm this start up the car and let it idle with a thermometer in the radiator. The fan should come on between 190? to 200?F. It should shut off at 182? to 188?F.
If it doesn't, you probably have a bad Cooling Fan Motor Switch or relay. It may be possible the fan motor itself is bad. If you run a fused, 15 amp, jumper wire to the blue wire of the fan motor connector, the fan should run. if it doesn't leave the wire hooked up and ground the black/wire.