Hi all, first post on this forum. So hi!
Just bought my mrs a Fiesta mk6 1,25. Nice little car but has a couple of issues tho.
Worst of which is the overheating.

After about 15 mins of a drive the temp gauge maxes out and the warning light comes on, fan kicks in as it should. To cool down the engine i put the heaters on which are red hot at first but soon start to blow luke warm..

So far I have changed the water pump, thermostat, (coolant obviously.) But still is the same. The bottom hose never seems to get that hot which is why i thought it was a thermostat at first..
Wondering what to try next.. Where is the coolant temp sensor on these cars? Also noticed when car is hot there is virtually no coolant in the header tank.

 

I managed to fix this.

There was a hairline crack in the neck of the expansion tank, thus letting air escape and the system not pressurizing. Fitted a second hand one and is now running great.