02 overheating: thermostat housing already replaced

[smoger]

Hey everyone,

Please excuse my lack of knowledge in this area.. I'm new to fords and a less-than-amatuer mechanic at best - i can follow instructions but thats about the limit of my abilities.. anyway, that being said..

My girlfriend owns an 02 focus hatchback and she's been dealing with overheating for quite some time. After she had the car looked at by the shop, they told her she had the common bad thermostat housing. I replaced that for her last night, and we drove the car around for about 20 minutes afterwards.. temp stayed perfect.. bone dry under the hood. Before we drove it we also let it sit still for 15-20 min and the temperature was fine like that as well.

Coming home from work tonight, she said that the car overheated while sitting in traffic, and then cooled back down, and stayed cool the rest of the drive home. I checked and her fluid is not leaking. What else could this be? Bad thermostat? I put in a brand new one when I replaced the housing.. is there a chance I could have done it wrong? Is there anything I need to do besides put it into the housing the same as the old one was positioned?

Thanks for any help!

[GapBoyPCS]

Usually an overheat situation like that tends to be an issue with the resistor pack that controls the cooling fan. It can be an issue with the Focus.

As you're driving, air is being shoved into the front of the car keeping the engine cool. As soon as you sit in traffic, there's no longer air being shoved inwards. So, there's no air movement to keep the engine cool.

That being said, it's good that you also replaced the thermostat housing because that tends to start leaking over time.

[smoger]

oh don't get me wrong,.. the housing DEFINITELY needed replacing. in fact, in addition to the usual crack on the bottom of the ring, there was a crack about 3/4 of the way around the edge of it. she'd been driving like that for almost 2 years before i finally convinced her to get it diagnosed and was refilling her coolant up to twice a week. so the fact that the system holds the coolant now is a definite step in the right direction.

thanks for the info on the resistor pack.. i'll research that.

[singleparin]

check also the radiator cooling fans if they are working or running, also check the fuses near the battery in the engine compartment before you replace anything just to make sure you don't have a blown fuse, i did that on mine and just wasted a decent amount of money, anyways at least now I have a spare part just in case for next time, LOL. good luck