I am not at the end of my tether with this issue.

I own a Ford Fiesta Freestyle (2001) Y-reg 52,000 miles.

I have a problem with my engine cooling, it is an intermittent problem which made me think it was the thermostat so I had it replaced.

For about 4 weeks I could drive it with absolutely no issues, then it started happening again, some days are worse than others but the issue is intermittent.

What I have noticed is that when I am driving the heating will go cold, then the engine will start to get hot. If I am lucky the heater will start working again and then my engine temperature will return back to normal.

Sometime I check to see if the water needs topping up as I am aware that my coolant is occasionally being boiled out of the expansion tank and the hoses look slightly bloated in places.

The problem seems much worse when driving up hill as oppose to downhill.

Any ideas?

I am not at the end of my tether with this issue.

I own a Ford Fiesta Freestyle (2001) Y-reg 52,000 miles.

I have a problem with my engine cooling, it is an intermittent problem which made me think it was the thermostat so I had it replaced.

For about 4 weeks I could drive it with absolutely no issues, then it started happening again, some days are worse than others but the issue is intermittent.

What I have noticed is that when I am driving the heating will go cold, then the engine will start to get hot. If I am lucky the heater will start working again and then my engine temperature will return back to normal.

Sometime I check to see if the water needs topping up as I am aware that my coolant is occasionally being boiled out of the expansion tank and the hoses look slightly bloated in places.

The problem seems much worse when driving up hill as oppose to downhill.

Any ideas?

i take it you are 'now' at the end of your teather. :) ok if you are boiling off your coolant then the easiest thing to replace is the expansion tank cap. if this is duff it will release pressure from the system causing your cooling fluid to boil off at a lower temperature.

your engine is getting warmer when the cooling fluid is not going through your heater matrix in the car,when it flows through the matrix again your engine cools, so you had the thermostat changed but has the cooling system been fully bled. you could have air blocked in the system ( however after four weeks i would have expected it to self bleed). when you squeeze the hoses throughout your cooling system do you see the level rise in the expansion tank. also the hoses being bloated could be air trapped, or a blockage in the system.check the system for the correct mix of water/antifreeze summer coolant 50/50 mix.

basic fault diagnosis:

when youve got time start the engine from cold, let the engine warm up, heater off, when the engine warms it will allow the expanding coolant to return to the expansion tank. you should be able to see this happening. now before the engine reaches its normal operating temperature, check the two hoses that go to the inside of the car on the rear bulkhead to your heater they should remain cold, take extreme care and if you can check the two hoses that go to the radiator these should be warming up.

now when the engine reaches its normal operating temperature the thermostat should open and allow hot coolant through the two hoses into your heater matrix check if they are now hot. now leave the car continue to heat up and your cooling fan attached to the radiator should kick in as youve got no cooling air through the radiator. at no time should steam/fliud be released through the expansion tank cap.

this is a basic test for you to try and eliminate obvious faults. like i said take care.

if you notice anything diffrent then repost as its hard to fault diagnose without seeing whats going on, and im sure some other mmembers will have some ideas to steer you in the right direction.

Cheers for the reply and advice Taff.

I am now at the end of my tether. :P

I know the cooling fan is working as I use it to cool the radiator on the hard shoulder when I need to limp the car along. I will check what you suggested tomorrow, I am also going to flush the cooling system after running the engine on a downhill slope hopefully any contaminants in the system will collect in the radiator.

A true testament to how intermittent the issue is, I managed to drive from Reading to Tolworth about 55 miles away and it wasn't until near the end of my journey I had problems. On the way back I had no problems at all.

Cheers for the reply and advice Taff.

I am now at the end of my tether. :P

I know the cooling fan is working as I use it to cool the radiator on the hard shoulder when I need to limp the car along. I will check what you suggested tomorrow, I am also going to flush the cooling system after running the engine on a downhill slope hopefully any contaminants in the system will collect in the radiator.

A true testament to how intermittent the issue is, I managed to drive from Reading to Tolworth about 55 miles away and it wasn't until near the end of my journey I had problems. On the way back I had no problems at all.

yep quite bizzare but by eliminating easy stuff hopefully you can get to the bottom of it. it seems quite erratic to be a cooling system fault though ( water is pumped, it moves) im wondering if there is an electrical sensor fault, however get all done then take it from there.