How to Replace the Thermostat in a 1994 Honda Civic

The thermostat on a 1992 Honda Civic acts as a gateway between the engine and the radiator. If your car is overheating but the top hose leading from the radiator to the engine isn't hot, then the thermostat may be stuck in the closed position. If the car takes longer than usual to warm up, it may be stuck open. In either condition, you want to replace the thermostat so your engine can cool itself properly.

Instructions

1

Allow the engine to cool completely, at least four hours, prior to working on the cooling system. Open the radiator cap, then place the drain pan underneath the radiator. Open the petcock on the bottom of the radiator with your hands and let the coolant drain from the system.

2

Follow the upper radiator hose to its connection to the engine, which is at the thermostat housing. Disconnect the hose clamp connecting the radiator hose to the thermostat housing, using the flat-head screwdriver to loosen the clamp and to pry the hose a bit if necessary (you can tear the hose, rendering it useless, so be careful). Pull the hose off the housing using your hands. Unplug the sensor connection to the housing using your hands. Unbolt the thermostat housing from the engine using the 3/8-inch ratchet and socket.

3

Pull the thermostat housing off the engine, then pull the thermostat out of its mount.

4

Install the rubber seal over the replacement thermostat. Install the thermostat into the housing with the tiny pin on the side of the thermostat pointing up toward the hood. Then reinstall the thermostat housing with the 3/8-inch ratchet and socket. Plug the electrical connection back in, push the hose onto the housing, and tighten it in place using the hose clamp and a flat-head screwdriver.

5

Fill the radiator using 50-50 pre-diluted coolant. Turn on the car and run it for 15 minutes with the heater on high. Check the coolant again an hour or so later and fill if necessary.