Here's one guys. I have a 1992 EX Wagon. I have replaced the radiator, water pump, thermostat (3 times) last one with factory Honda,radiator fan switch, radiator cap, flushed the system twice, heater control valve works. Fan's never come on and gauge operates normally. Here's the bad, It's is overheating. Today I drove it a short distance and used a good infrared temperature gun. The water outlet at the front of the head showed 215 degrees and the thermostat housing (where radiator fan switch is located)is only 139 degrees, the circuit is designed for the radiator fan switch to come on first. It can't come on and the thermostat won't open at only 139 degrees. I did a compression test all cylinders were at 175 psi and checked the timing and is dead on at 15 degrees BTDC. No signs of oil in the coolant or coolant in the oil. With the key on if the radiator switch is unplugged and the terminal is jumped, the fans work as they should. There are no signs of internal or external coolant leakage. It seems to me that there is a blockage somewhere and I have put the garden hose through all of the hoses. Before I put a new motor in this anybody have any ideas?

 

I had a very similar problem with my 96'. Almost identical actually. I ended up changing my fan switch twice. I don't know what happened the first time. I changed it, the car still overheated, so I figured that wasn't it. Roughly a year later, dealing with it the whole time, trying other things as you have, I changed the fan switch again and the problem went away. Good luck.

 

I've had the same issue with my 92 accord ex. I haven't checked with infrared but noticed the fans weren't coming on. I checked and top hose was hot while lower hose was always cold even though gauge read in the middle. I changed and checked thermostat which checked out fine. The car has been like this for at least two years with no problems. Also both fans will come on when a/c is turned on. Let me know if you find a solution or if this is normal. I also remember when the car was new the fan would come on sometimes in the driveway after shutting engine off. This doesn't happen anymore.

 

I would say my instance is not normal. I also have a Dodge Ram which I'm forced to use as a daily driver now that my Accord is down and I put the heat gun to it after I got home today and the water outlet temp was only 188 and the cylinder heads were 179. I would say the 215 I am seeing in my Accord is not normal. We also have a new Odyssey, I am going to take that for a drive an see what temp it runs at.

 

Do your fans kick on when you turn the car off? In the problem I had they did. If I shut the car down when it was over heating, the fans would kick on. If I remember correctly it was because the second ECT switch recognized the car was hot and turned the fans on. When I found that out is when I went back and looked at the ECT switch on the thermo. housing. If your fans don't ever kick on, you 215 may not be hot enough to worry about. I don't know for sure though cause it does sound pretty hot.

 

Villian, which radiator fan switch did you replace? The one in back, in the thermostat housing, is responsible for switching when the engine's running. The one at the upper radiator hose is responsible for switching after turning the engine off.

SteveZ, a subtle difference... If the radiator has enough scale & crud, the flow thru the radiator will be small. The waterspends plenty of time in the radiator & gets cool, so the lower radiator hose will be cool. But the flow rate is too small to adequately cool the engine.

 

The radiator is only two months old. When I changed it I did use the bleeder screw while filling with coolant to let the air out.

 

Did anyone ever pour that stop leak crap into your old radiator?
For starters let us know which fan switch you replaced and if they ever come on,
second, when you replaced the radiator did you use a new radiator cap? Make sure that it hold pressure properly.
When it starts to overheat does it overflow into the overflow tank?
Which temp thermostat did you put in?
Is it OEM Factory Honda?

 

I replaced the fan switch in the thermostat housing, this is for the radiator fan. The thermo is a factory Honda. The fan switch on the outlet of the cylinderhead isis for the A/C cooling fan. This switch is designed toturn on the aux. cooling fan between 212 and 232 degrees. If it is a hot day and the A/C is working the motor hard the switch will activate the aux.cooling fan. What happens when you hear a fan come on after the motor is turned off is the is thatthis switched isclosed because heat from the head/blockis transfered to the coolant which isn't flowing because the motor is off. Once the coolant is hot enough to activate this switch (212-232) the fans are turned onvia the fan timer module. Tonight I disassembled most of the cooling system. I removed the dash to replace the heater core (WHAT A JOB THAT IS) I am going to flush everything out really well and reassemble. I am also going to try a Stant thermo this time.

 

Forgot to answer some of your questions. Yes brand new cap. I am finding small particles of ???? in the thermostat housing and hoses. There could be a clog somewhere because some idiot put stop leak in the system. We'll see what I get out of it when I flush it.