My daughter's 2003 Ford Focus is in the red. We changed the thermostat yesterday and it seemed fine. This evening it ran hot again. She had to replace the coolant again. We don't see any signs of leakage so what could it be? Sorry I don't have more info because I don't know anything about cars. Thanks in advance for all help.

Look in front of the radiator & berween the radiator & ac condensor for trash. Also check to make sure the electric cooling fan is working.

If it only get hot at stops or driving slow, check to see if the cooling fan works. Also check on the radiator cap if the seal is broken or worn.

Will check that too. Thanks!

Check radiator fan.
Check to make sure radiator cap actually holds pressure in system, have mechanic do a pressure test.
Check water pump.

Did a mechanic change the thermostat?

If she's getting close to the red zone, she can roll down her windows and turn on the heater, the heater is essentially a small radiator that draws heat from the coolant.

One other thing you can do is when it starts getting hot turn the heater on full blast. That will help save the engine in a pinch. It does sound like a cooling fan problem wether it's a sensor. Start up the car and turn the a/c on. If both fans start working when the a/c is on then my bet is the sensor.

Is the Radiator staying full? If you had to ad coolant then it is leaking somewhere. Often if a head gasket is leaking you will not actually see any water as it will evaporate as it boils out of the motor.

To help troubleshoot it better can you tell us if it does this while at idle, or at highway speeds?

Does it overheat faster when the AC is on?

How many miles are on the car?

Who replaced the Thermostat? Was it replaced with an actual Ford Thermostat or a a cheap aftermarket one?

Regards

They were on 35 headed home traffic got heavy and they had to slow down and it went in the red, when the were able to speed up it cooled down a bit. There are almost 56K miles on the car. A friend changed the thermostat. He is checking it now the fan is working. She did not have a/c on, but he has it running now. Bought thermostat at parts store. Is the sensor something we can replace or should it go to dealer?

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Mechanic thinks it is a cracked gasket. Car is at the Ford place for repairs. Luckily I have a service contract and should only have to pay $50. Thanks again for all the advice.

Focus' cooling system is a nightmare to work on, from my experience it could be that you may have gotten a bad thermostat. It could also be that housing that the thermostat sits in, the seal around it is notorious for leaking, which can cause it to over heat (its called the coolant housing). It could be that you may have air in the system (most likely to be the problem), if you dont get all the air out of the system it will over heat, there is usualy a bleeder valve somewhere, or you can fill it up with coolant, let it trun untill the thermostat opens, relieve the pressure in the system and top it off with coolant untill there are no more air bubbles in the system. It could also be a clogged hose, or even a clogged radiator. But imho i would probably take it to a shop, not the dealer due to the fact that they charge and arm and a leg, but i would take it somewhere like firestone, goodyear/lambs, sears, NTB, or some shop like that where it will generally be cheaper, and you will still get a warrenty on the work...

Hope this helped
Chris

I wouldn't say too fast that aftermarket shops are cheaper. I work at an Infiniti dealer(yes we're expensive) & the last time I checked the Firestone 2 miles away was $10hr higher.

yeah, firestone is probably the most expensive shop around, im pretty sure they charge 3X parts and $84 an hour, but im pretty sure the other shops are cheaper, used to work for sears and NTB, pretty decent with their prices

She already has it at a Ford Dealer looks like. I almost missed that after I typed a huge paragraph and posted I noted that she edited her thread. Hopefully they will get it fixed for her.

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Mechanic thinks it is a cracked gasket. Car is at the Ford place for repairs. Luckily I have a service contract and should only have to pay $50. Thanks again for all the advice.

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Thanks again for all the advice, if I remember I will post the final diagnosis. EnJOY the rest of the weekend.