Hi
I have a Fiesta 1.4 56 Plate Zetec mk6 Petrol which developed an overheating problem.
I have changed the cylinder head gasket and had the head skimmed and pressure tested at the same time.
I also checked the water pump impeller as I replaced the timing belt at the same time.
I rebuilt the car and it ran fine for about a week or so and its overheated again. and I have no idea why its used water but there is no external leaks and its not gone into the oil and also doesnt seem to be buring off as the car is running great.

Is there anything common with these models of fiesta that i may have overlooked. Can anyone point me in a direction.

Im not a mechanic as such but ive stripped and rebuilt engines for years so I have a good idea what im looking at I just need some guidance here. Anythiung will be appreciated.

 

You seemed to have checked all the basics, were they all ok (get a feeling they were)? Have you checked the thermostat? And are you sure there isn't a blockage anywhere? Does your heater blow hot or only cold? Have you had a compression test done?

 

The only thing I found when I stripped it down was the cylinder head face was in poor condition. I took it to my local engine services who said the face was a mile out before he skimmed it. I put the over heating problems down to this.

Both the top hose and bottom hose are getting warm which tells me the thermostat is working ok and water is circulating. Unless you can advise me differently?

 

Does the fan cut in?

 

I havent heard the fan cutting in to be honest but i checked the fan fuses etc and all was good. I think I'll run the car and listen for the fan.

I heard something about these fans being controlled from the ECU and sometimes the ECU fails has anyone else heard this ?

 

It is possible.

I recently looked at a Focus with ECU controlled fan. I could switch the fan on via low and high speed test on the Ford IDS dealer tool, but it would not cut in automatically.

If I shorted the relay or powered direct from fuse it would cut in.

Check fan operation, I think there's a relay in the box near the battery for it. Check the wiring where it goes from the connector to fan, I have seen them corrode before too.

 

Good idea thanks for that. I'll bark up that tree tomorrow and see what happens.

I own a remapping business and can re programme ECU's for performance etc but unfortunatly my kit wont go as far as investigating faults like this so might have to take it to a dealer if it looks like its the ECU

Thanks for your time

 

OK Guys another question, I have messed about some more with the car and 2 things have came to light, First of all there seems to be air in the water system and I have spent hours trying to get the air out, ive tried the old 2L water bottle in the expansion bottle trick to create a high point higher that the engine but there still seems to be air in the system I am running it untill its at working temperature but no joy and its had a new thermostat so definatly not that either.

Issue number 2, The cooling fan is not kicking in. As we discussed above I am aware this could be an ECU fault but can anyone advise of any lines I can investigate before i diagnose an ECU Fault

As I said Im not a mechanic but worked with cars all my life so I do have a pretty decent basic knowledge if that makes sense.