How do you replace the thermostat located on a Ford Fiesta?

Answer 1

When the engine is cool, remove the two retaining bolts (HCS engines). Remove the top half of the thermostat housing. The thermostat will be situated in the middle of the housing when you remove the top half. If there is a retaining clip remove this first and then withdraw the old thermostat. Scrap away any parts of the old gasket lightly with a screwdriver and whip away any lose gasket peices. There has to be a smooth finish for the new gasket otherwise there will be leaks. Try not to get any of the old gasket into the water system. Replace with a new thermostat and gaskets. Then re-attach the top half to the thermostat to the correct torque settings. More input: * The answer so far works, but there are some "got-ya" issues. I think that you need to undo the two nuts( one at the rear and one at the front of the engine) that holds the water coolant line. Now you should be able to remove the bolts holding the thermostat housing more easily. Also, after putting the new thermostat in, you will be able to put the bolts in straight and get an accurate reading on your ft/lbs. You also won't strip or cross thread the threads for the bolt holes on the aluminum head (8mm 1.25 pitch tap needed if you do. (smile)