Contour Enthusiasts Group Archives Forums General Troubleshooting Zetec overheating: "fan sensor" needs replacing?

So after our first mechanic decided the car wasn't "worth fixing" (though he kept offering to buy it... yeah right).. we asked for a 2nd opinion (from another mechanic of course)..

He checked over the car and discovered that while the fan wasn't running as it should, it came on just fine if you turned on the defroster, his diagnosis was the fan sensor wasn't working right..

Not knowing where that was, he said he'd ask a friend of his and get back to us, so in the meantime I took up a friend's suggestion and got a hayne's manual for the car (about damn time)..

What I do see is info about a coolant temp sensor, and how to replace it, which really looks rather harmless, though testing it requires an ohmmeter I don't happen to have on me! :\

When starting the car, the fan will go on, hit full blast, turn off unless said defroster is on (from what I know anyway) -- makes sense since the first few times I drove the car I used said defroster and never saw overheating.

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Last question: The janky mechanic replaced the fuel filter after the CEL came on/off like as if the car was misfiring, can a bad fuel filter cause misfires? I guess I won't know until I take the car out for a bit (once said overheating is solved) but yeah..

How high is the temperature on the gauge? Overheating could be caused by: the water pump, the radiator needs flushing, thermostat, head gasket. The radiator fan seems to be operating normally, comes on at startup, the with defrost (A/C also). You could disconnect the ect sensor and start the car, the fan should come on then also, with a check engine light. This thread involves the head gasket, replaceable with effort. He had major exhast fumes emanating from the coolant tank if the cap was off. http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=trouble&Number=1082656&page=0&view=collapsed&sb=5&o=7&fpart=1

Tony 2005 says try simple and inexpensive first, good approach. When you reach the expensive, you know you need it.

Mechanic and I have both tried with the cap off, no exhaust fumes off the coolant tank

FWIW, the intermittent heat problem usually associated with a serious problem isn't there.. we tried the equivalent of setting a brick on the gas for a few minutes [just up to 2-3krpm!] and the heat was still running just as hot as when we turned it on (ya know, the usual hair dryer hot )

I don't think running the AC helps the temps any..