I have a '97 Civic DX that was having some overheating issues. The radiator was cracked, and not holding pressure. I replaced the radiator, thermostat, and the upper hose (it made a crackle sound when squeezed, figured it was baked from the overheating). I back flushed the system before installing the new radiator, than after than install I bled the system of air by idling with the radiator cap off until it stopped bubbling.

The car was still running hot at stops/traffic, my next step was to see if the radiator fan was running. I idled the car up to normal temperature, fan did not come on. Than I drove it around a little bit, and stopped, temperature gauge climbed all the way up to hot, still no fan. I jumped the ECT switch, and the fan came on, so I replaced the ECT switch.

However, the fan only comes on when the temperature gauge is reading hot, or very close to it. Currently I have the ECT switch jumped, so that the radiator fan runs 100% of the time, and the temperature gauge stays in the normal range (1/2 between cold and hot).

Any ideas?

 

For the moment, it appears as if I have solved the issue. I didn't locate the drain plug for the block, to bleed the system. But I took off the upper and lower radiator hoses, filled them and the thermostat housing with coolant, re-attached, than ran some water through the back flush T to make sure any air was out of the system.

Once I did that, the radiator fan began cycling as it should, and the temperature has not moved above it's normal operating reading. I'm guessing that there was some air trapped in the thermostat housing, or around the temperature sensor that was causing the fan to not cycle, or the sensor to read high.

Hopefully I've got it fixed, I'll update if not.

 

Congrats on the fix. You really don''t need to remove the drain plug from the block to bleed the cooling system. I assume that the system was not properly bled the first time around.

 

Good day
I have honda civic 1.8 2007 model car. From few days i am getting problem about my car radiator cooling fan comes on when the engine is start getting hot on the meter. His needle goes up to the normal. Its heppened when i dive my car in busy area or stuck in traffic
Plz sugest something.
Thanks