Kinda bummping a previous thread from a month ago. Since I have fixed a few things but still have 1 problem. I have a 91 accord ex. It gets hot when I am Idoling at a stop and in stop and go traffic, but goes down and run good when I am driving. ( I can also control it slightly by cranking the heater) I checked the coolant and it was low, so I filled it. Ran 2 days and it still got hot. when I let it cooldown in the garage and opened the radiator cap, the radiator had pressure and looked low again, but the overflow res. is now full.

Sooo...Fine when Driving, not when Idoling in park. I do not believe the fan is coming on while the engine is running. It does come on when I shut it off. I swappped the fan switch in the thermostat housing with another one, but no effect. I can jump the connection at the fan switch while the car is running and the fan will come on. Any suggestions of where to start? Thanks

 

burp your system...park on incline or jack up the front, take rad cap off let engine run till the fan kicks on 2x's.. fill as needed.. You might want to do a block test.. they sell them at napa or other parts stores

 

You keep saying "the fan". BOTH fans should come on when you jump the wires on thermo a (the one on the t-stat housing) and the key is "on".

If the ac is working, BOTH fans should come on when the car is on and the ac is turned on.

Now back to the issue. Sounds like you are loosing coolant. If you are having to add to the rad, it is going somewhere. As suggested be sure to bleed the air out of the cooling system.

 

Its also possible you have a small leak in one of your hoses if needing to add coolant. Try using another radiator cap and bleed the air out of the cooling system. Does the fan come on when you run the AC?

 

As far as I can tell, the AC does not work. When I turn on the AC, no fans come on.

I will look at the fans again tomorrow after work and note what comes on and when and try to be detailed in what wires and switches I am jumping.

It would seem that I loose coolant somewhere, but just am not sure if it isn't pushing it to the resevoir when it gets hot because that seems to be over <MAX>. The radiator cap seems to be making a good seal because it reseales pressure when I open it. If there is more to the cap than that, that is a totally easy fix. Seems cheap enough to replace that even if it isn't the problem. I imagine anything with a rubber seal on a car this old can stand to be replaced. :-)

THanks for the help, I will get back with more details. ~Robert

 

Have you check your water pump?

 

Water Pump was one of my original thoughts, but I've been slammed with work. I haven't gotten to really do much testing of anything. it seems to be running alright, I just put 1/2 quart of water in the radiator every 2 days. I will get back into toubleshooting problems with it ASAP. Thanks

 

Even if you have the tiniest hole in your coolant system, your fans won't kick on. Causing it to over heat.

Idk why, but everytime I have ever had a pinhole leak, my fans never came on, Even when it got hot...figured it being hot would cause them to kick on,

 

Think about the properties of water/coolant vs air. Also think about the position of the two sensors/switches.......

 

sounds like your water pump to me...the water pump has a hole on the side of it that is made to leak water out of it when it goes bad....if you have water leaking out of it....that's where you water is going....and if you are not getting water through your engine your fans won't kick on if they don't know how hot it's getting by no water getting to the thermostat..it has no way to tell how hot it is.......check that first....

 

my accord 92 was overheating go this http://techauto.awardspace.com/index.html