Hi everyone, hope you're all well. Thought id try and rack your brains and get a bit of advice, with an issue ive got.

2005 mk1 1.6 Ford Focus Zetec 47-48k miles. Its got a single radiator fan, not twin.

Had problems with it overheating within a couple of months of buying it. Temp gauge would

go to red at persistent speeds of 40-50mph+, steadily got worse, and would overheat at 20-30mph. Within minutes of the temp gauge going to red, engine light comes on, loss of power, juddering. No fluid loss at all at any point.

Took it to a garage

1) Said they pressure tested it.

2) Said from the symptoms I described it was a headgasket/cracked block/cylinder.

Quoted eye watering headgasket prices at best case, might as well scrap the car, block prices, at worst.

3) Charged me a fiver :D (Is that a good sign or a bad sign)

4) I thought this was all a load of !Removed!, due to the price they charged, and due to no fluid loss at all (There isnt always fluid loss with headgaskets ? but i just didnt think it was as drastic as a block or gasket issue).

Took it to who I bought it off, narrowly past the 1month/1k miles warranty.Lent on them a bit to do something. They had the car for a couple of days, drove it around. Doubted it was even overheating, and started to blame the instrument panel, or its a sensor, but not a headgasket. In their words, whilst revving it, 'it would be !Removed! with coolant'. They basically refused to do !Removed!, 'Oh itll be a sensor, just about finding which one'.

Took the car away

1) Changed water
pump

2) Changed

thermostat

3) Changed cylinder

head sensor

4) Coolant flows/no cold spots/anything particularly obvious. No fluid loss. Engine ticks over nicely idling.

Still overheating.

Went to a ford dealership to talk to a mechanic, to see what I could get out of him.

Said check for air in the system, he rarely see's headgaskets, couldnt recall ever seeing a block problem. Gave me the number of a mechanic that used to work there that now works for himself.

I took the car away, flushed the system, put the coolant back in carefully. As if by magic

after !Removed! about with this and that, it didnt overheat any more.

Driven 5k miles since, no issues.................................. it did 60/70/80+ for 1 or 2 hours at at time, in summer, aircon on cold, no problems at all. Havent driven it any longer than that at once.

This week, on a dual carriageway, got up to 50mph, and the temperature gauge !Removed! went

to red. Engine light, loss of power, judder.

So where to begin now ?.

Is there any point buying ELM ODB2 + software, and seeing what fault codes come up

when its pushed ?. Is there many sensors on the mk1 that would be relevant ?. Would it show up issues with cylinders or a headgasket, the radiator fan ?.

How to test the radiator fan ?. (It comes on when aircon is switched on).

Any way I can find out at home, if its 100% not a headgasket issue ?.

ECU ?

Kind of running out of options before it starts to turn very expensive it seems. What

would you do if it was your car, besides getting rid. If i can rule the radiator fan out, it can only be a head gasket ?. Should i take it for diagnostics somewhere else ?.

*sighs.

Zetecs don't tend to loose much fluid with head gasket and are very prone to blowing them (5 times on my last Zetec engine), does sound like a head gasket. Warning when it does finally fully go it will be pretty spectacular, lots of steam etc and totally dead engine. If you get it before that you can have head skimmed and new gasket (always skim head of it will go again straight away)

Most garages can test for a head gasket leak very quickly and easily, The have devices that check for oil and exhaust gas in expansion tank and water in oil

Symptoms are definitely of overheating

I would check thermostat, both temperature senders (gauge and ECU sender are not the same on the Zetec). Also the design is that the sender can be sitting in cool water even though the engine is too hot. Check fan also runs when aircon is off when engine at full temp and car stationary

Does the tell tale water jet in the expansion tank flow when the engine runs (if not, could be water pump). Whn the car is cold, start it and feel the hose between the thermostat and radiator. Should stay cold for around 5 mins then suddenly get hot as the thermostat opens. Squeeze it and see if you can feel air in the system

Zetecs don't tend to loose much fluid with head gasket and are very prone to blowing them (5 times on my last Zetec engine), does sound like a head gasket. Warning when it does finally fully go it will be pretty spectacular, lots of steam etc and totally dead engine. If you get it before that you can have head skimmed and new gasket (always skim head of it will go again straight away)

Most garages can test for a head gasket leak very quickly and easily, The have devices that check for oil and exhaust gas in expansion tank and water in oil

Symptoms are definitely of overheating

I would check thermostat, both temperature senders (gauge and ECU sender are not the same on the Zetec). Also the design is that the sender can be sitting in cool water even though the engine is too hot. Check fan also runs when aircon is off when engine at full temp and car stationary

Does the tell tale water jet in the expansion tank flow when the engine runs (if not, could be water pump). Whn the car is cold, start it and feel the hose between the thermostat and radiator. Should stay cold for around 5 mins then suddenly get hot as the thermostat opens. Squeeze it and see if you can feel air in the system

Thanks for the reply, interesting and useful. I dont have a huge amount of experience and knowledge really, its only my 2nd car. Probably hold me in good stead for the future, absolute pain in the !Removed! right now though.

So, first things first.

The radiator fan should come on when the car is stationary, warmed up, ?. Is that a good indicator nothing is wrong with the fan/sensor ?. Ill check that. Just out of curiosity, i wonder how single fans work in terms of radiator cooling, sensors, and aircon. But if the fan is coming on by its self, i can more or less cross any fan issues that off the list ?.

Coolant definitely flows by the looks of it, it is a jet, and the water pump was changed a year or so ago. I'll feel the hose as you mentioned just to double check that. Would you just run the sensors/thermostat thing by me again. So theres the thermostat that opens as temp rises. The cylinder head sensor was changed also i think, and i assume both are alright as they were changed pretty recently. Is that it ? Or there is another related ?. (I dont really know much about this).

Besides those, looks like im off to the garage for a definitive answer on the head gasket. What tests should they be doing, and how much should it be costing ?. I suppose im too far down the road to doubt it, but i need a 100%, rather than a sounds like it, because its going to be expensive isnt it. I could get someone to do me the head gasket labour free. But how much would I be looking at to skim the head ?. The car is worth like 1300, is it even worth doing ?.

Also, from the initiative symptoms, ive driven like 5k miles, if the head gasket was on its way out, is that normal ? or a case of how long is a piece of string.

Thanks again.

Zetecs are not prone to head gasket failures never even had one with a gasket failure either owned or through the garage that includes fiestas and escorts the early silver top engines it could be a weak point mainly due to not using proper coolant ratios other than that misdiagnosis many have bern told its s head gasket from garages and yet a simple coolant pressure cap fixes it so im shocked that not one person has changed the pressure cap on the coolant tank yet... it costs about a tenner and if faulty will prevent the system from pressurizing causing overheating particularly at speed so IDE change that before doing anything

The fans a double speed fan with air on it runs at speed one to aid cooling it switches to the second high speed mode then drops down to the normal mode again