94 escort wagon

[pistol010672]

i have a 94 escort wagon that heats up when idleing fluid is good how do i test the fan?

[mightymoose_22]

Your coolant level may be good, but the coolant may not be circulating.

You can check the fan several ways. The easiest might be with a code reader if you have one. A code reader can run a diagnostics test on relays and will test the fan on both high and low speeds. You can also test the fan at high speed by turning on your A/C. The fan should operate at high speed when A/C is on. Another option is to disconnect the temperature sending unit while the engine is running. With it disconnected the computer will think the engine is hot and should turn the fan on. There are several other ways too, but these ways are simple enough.

As for circulation, when the engine is cold, start it up and then feel for warmth and pressure at the upper radiator hose. At first there should be no pressure and the hose should be cool. Once the engine reaches operating temperature the thermostat should open up, at which time you should feel the coolant rush through the hose and build pressure and warm up. If you can't feel the pressure there when the engine is above operating temperature, or if the hose never warms up, then you have a circulation problem. Either you have a blockage in the radiator or the heater core, or your thermostat is bad and is not opening.

Do a little bit of diagnostics to narrow down the options and report back with the results.

[pistol010672]

my fluid is circulating, and the fan turns on with the ac but does not come on otherwise

[pistol010672]

where is temp sending unit located

[mightymoose_22]

If your fan comes on with the A/C on, you can be pretty confident that nothing is wrong with your fan.

If you are confident that you have good circulation and the thermostat is operating properly, I think the next think to consider is the sensors.

In the output hose from the heater core that leads to the thermostat housing you will find two sensors. The forward one, closer to the housing, is the sensor that is responsible for signaling the computer to turn on the fan. If it is not functioning properly... then that may explain your overheating.

The other sensor simply sends signal to the gauge.

Out of curiosity, how hot is the engine getting? What does your gauge show you?

[pistol010672]

Originally Posted by mightymoose_22

Your coolant level may be good, but the coolant may not be circulating.

You can check the fan several ways. The easiest might be with a code reader if you have one. A code reader can run a diagnostics test on relays and will test the fan on both high and low speeds. You can also test the fan at high speed by turning on your A/C. The fan should operate at high speed when A/C is on. Another option is to disconnect the temperature sending unit while the engine is running. With it disconnected the computer will think the engine is hot and should turn the fan on. There are several other ways too, but these ways are simple enough.

As for circulation, when the engine is cold, start it up and then feel for warmth and pressure at the upper radiator hose. At first there should be no pressure and the hose should be cool. Once the engine reaches operating temperature the thermostat should open up, at which time you should feel the coolant rush through the hose and build pressure and warm up. If you can't feel the pressure there when the engine is above operating temperature, or if the hose never warms up, then you have a circulation problem. Either you have a blockage in the radiator or the heater core, or your thermostat is bad and is not opening.

Do a little bit of diagnostics to narrow down the options and report back with the results.

the fluid is circulating the fan comes on with the ac but nothing on its own,where is temp sensor located? is it next to the sensor that runs the temp gauge?

[pistol010672]

Originally Posted by mightymoose_22

If your fan comes on with the A/C on, you can be pretty confident that nothing is wrong with your fan.

If you are confident that you have good circulation and the thermostat is operating properly, I think the next think to consider is the sensors.

In the output hose from the heater core that leads to the thermostat housing you will find two sensors. The forward one, closer to the housing, is the sensor that is responsible for signaling the computer to turn on the fan. If it is not functioning properly... then that may explain your overheating.

The other sensor simply sends signal to the gauge.

Out of curiosity, how hot is the engine getting? What does your gauge show you?

i havent let it get to hot but it has made it just past the l in normal

[pistol010672]

Originally Posted by pistol010672

i havent let it get to hot but it has made it just past the l in normal

the fan comes on with the temp sensor off. i just got the car so i dont know when it was flushed last so that might b the next step? the fluid looks good but that probably dont mean anything?

[mightymoose_22]

Sounds like your fan works fine... it is just not turning on when it is supposed to. You can try replacing the forward sensor (closest to the thermostat) and you can check the fan relay that is in the fuse box in the engine.

[AzTumbleweed]

Yes, the sensor is located next to the one that works the gage.

[tripletdaddy]

It's the one with two wires going to it. The other sensor for the temp gauge in the dash has only one wire to it.

And by the way, the coolant is pumped thru the engine from the water pump to the heater core hose, the bypass hose and the thermostat and upper radiator hose. Then the coolant RETURNS to the pump via the heator core, the radiator, and the bypass hose. The hoses connected to the water pump go INTO it, not away from it. JFYI

[KimMG]

The only thing I can add is check the radiator for possible blockages. After the car gets up to operating temperature, turn it off and disconnect the battery. Now feel the radiator for cold spots. Cold spots are indicative of internal obstructions.
Make sure the fins in the radiator are clean, free from bugs and other debri that would inhibit air flow.
Are there any missing parts around the radiator, interfering with air flow?

[cclouser88]

The fans not supposed to come on till just past the L in normal it doesn't leave much room for error but as long as the car is moving it will cool it's self the fan also doesnt stay on that long just long enough to bring it back down between the R and M whitch only takes a second