Thanks MK. I was able to get a replacement bolt from my local hardware store. New thermostat is installed I took the car for a spin and didn't experience any overheating. I should know for sure this afternoon in the stop and go traffic. Thanks again!

 

*Update* Thought everything was fine after replacing the thermostat. To my dismay the car started to overheat when idleing in traffic. I quickly pulled over and popped the hood. I noticed that neither of the fans were spinning. I remember reading on this forum that the first step is to hot wire the fan. Can someone explain how to do this. I noticed a wire boot on the thermostat housing. Do I pull the boot off and cross those two little electordes with a paper clip? I tried touching both together with a flat head screw driver and it didn't do anything. Thanks for all your help again!

 

First bleed the cooling system:

(This procedure may take 20-30 minutes)

1) Park the car on an inclined driveway with the front end higher than the rear.

2) Push the dash heater lever/**** to MAX heat.

3) Follow the directions in the diagram below

 

So I was able to complete the circuit with my fan. I unhooked the wire boot that connects to the thermostat housing and stuck a paper clip in the boot to complete the circuit. The fan started up when I did this. I read that if this happens it could be the fan relay. So I swaped the fan relay with another one and let the car idle. The fan did not come one once in 25 minutes.

I appreciate the advice on bleeding the cooling system. I have my doubts that that is the problem though. Shouldn't the fan on the passenger side come on atleast sometimes? I noticed that the driver side fans spins up when I turn on the heater.

 

If the fan runs when you jump the connector, that shows the fan and relay are OK. Test drive with the paper clip in and the fan running constantly and confirm there is no overheating(*). The problem must then be the switch in the thermostat housing not starting the fan when it should. Replace it.

Fan on the passenger's side cools the radiator and thus the engine. Fan on the driver's side is for the air conditioner only. The two systems are completely independent.

(*) You can use the car for a few days with the fan hotwired but don't consider it a permanent solution because there will be excessive wear of the fan motor and eventual failure. The motor costs a lot more than a new switch.

 

+1

I was experiencing overheating symptoms as well, very similar to yours. I jumped the fan circuit and ran like that a few days. Replaced the ETC switch assuming it was dead. No solution there.

My problem was air in the cooling system. I have never had so much trouble bleeding a cooling system as I have on my civic. Take my advice and do it RIGHT. Drain it all out and start from scratch if you must.

I had the front of the car jacked up so the car was sitting at about a 20 degree angle. Filled it with coolant, ran it for 10 minutes, then put the rad cap on. Went for a smoke or 2 with the car running and the rad cap on loose. (not totally sealed, but enough that it was snug). Carefully opened the rad cap (burned my fingers even though I used a rag) and slowly poured in coolant till it was full. Repeated the proceedure, and got more air out again. 3rd time it was finally full of coolant with no air in the system.

Hope you manage to find the problem. Don't overlook the simple things like I did

 

Thanks SilverSedan. I'm glad I read your response. I was just pricing a new ECT sensor. I guess I'll try bleeding the cooling system properly. I was also of the belief that you can fun the car with the rad cap off and keep adding coolant as the bubbles come out. Guess that is not the case on the civic. I still think it's weird that the fan doesn't come on when the engine is hot. Did your fan start working when you bled the system properly?

 

The diagram I posted is the proper way to bleed the system. There's no need to drain the system.

 

Hi Ron. So you think the fan will start working again when I bleed the air out of the cooling system?

 

Well from my experience, replacing the ETC switch did NOT solve the problem. Having the patience to bleed the cooling system properly DID solve it. (however I was hit with a few different problems at once so I was having problems troubleshooting everything)