Hello

I have just bought a 2000 1.5 Fiesta Ghia that has a zetec engine. I have been having intermitant over heating problems and while not a mechanic I can find nothing similar in my searches and had a mechanic look at it today who was left unsure of what the problem may be.

Thermostat is working as tbe radiator is getting hot. the hoses to top and botton of radiator are getting hot

When the car overheats I ha e found that I have had to put in around a litre and a half of water but at other times the water level is spot on... there are no signs of leaks

the heater gagss in the car areall set to cold... but the car gets very hot (open window time)

oil is all clean so no water getting into head

I can drive all day around town and up motorway and have no problem... then it can overheat again with no notice

the temp gauge can go right into the red and then back down to mid way ( a yoyo effect)

the radiator fan kicks in most of thd time.... not sure if its supposed to in normal running

The car is fine while running at standstill and temp gauge sits easily mid way

Im not sure what to look at next so if someone could help that would be great.

Thanks

Have you changed the expansion tank cap. It may not be holding the pressure. Should be changed regularly anyway and only cost a few quid.

ahh ok i was looking for the expansion gank and thought i didnt have one but its just clicked... it is the tank i fill up the water into isnt it. (feeling thick)

Thanks Bruce Ill pick one up tomorrow

Hi as above the cap would be a good place to start .you may try to change the thermostat as if it is not opening fully this may let the car run HOT and only sticks shut the odd time .A new Thermostat will not cost much and is 1 less thing to look out for.(A YoYo effect) this will be the Thermostat sticking shut and then opening.

Thanks Dah,

I changed the expansion tank cap with a ford part and i realised that i had been filling it to the absolute top with water ... so above the max level.... wonder if the steam and water loss was due to that? the water level is now within the min max levels

after replacing the cap i drove around town and motorways for about 100 miles... the temp guage ranged from middle to right into and passed the red... but it didnt over heat. I also noticed that the water level in the expansion tank has stayed at same point.

i have run the car at both fully cold and fully hot on heater gauges and this made no difference. a mechanic said the stat isnt a problem... but as you say, for a few bob and some work... it cant do any harm.

Thanks

When was the waterpump replaced? could be that it's knackered and not pumping the water around properly, common thing on all cars when they get on, cheap enough to replace but you'll need an AUX belt kit at the same time.