Since the cooling system needs to be flushed before fitting a new heater valve I decided to change the thermostat as well. As you may have seen in my other videos regarding thermostat housing leaks on the Fiesta and Ka, these Endura-E OHV engines are reliable but only with regular servicing - and that includes coolant level checks and two year change intervals. The Endura-E is basically a tweaked version of Fords ancient pushrod OHV lump which means an iron block and head. This is why coolant of the correct specification and strength needs to be used to prevent scale and rust build up within the cooling channels and radiator. Fiestas and Ka's from mid nineties up to 2002 need the long life orange coloured antifreeze. (Check your manual for exact type). In the video you can see how gunged up the thermostat was plus it was leaking past the housing and onto number one spark plug which can rust solid into the head if not sorted out. In the next video I will show the installation of the thermostat AND the new heater valve and refilling & bleeding the cooling system. Stay tuned for more videos coming soon.