Overheating Issue 1.6 Mk1

[Blagger89]

Hey all,

2002 51 plate 1.6 Zetec Focus here.

Car was overheating and RAC came out and said thermostat has gone, so I've bought a new one and fitted that, checked the housing and it doesn't show any visible cracks.

Still overheating and losing coolant (however it might be too watered down as I've done a few flushes over past few days) but showing no signs of any leaking.

Took the thermostat out and back in today, and then left it idling for 20minutes with fans on showing no issues, then took it for a drive round the block for 15 minutes and the temp gauge jumped up again to red zone but no warning lights came on, then the fan kicked in and the temp gauge went back to normal.

Opened the bonnet and the coolant is lower than when I topped it up however I suspect this is due to the water ratio being wrong and it evaporating off.

Checked all the hoses and they seem all fine, and the expansion cap seems fine and no issues there.

Anyone else got any ideas what I can look at before taking it to a garage? Ive ordered a new housing for the Thermostat and thats on its way

Cheers for help in advance.

[mjt]

The water/antifreeze ratio doesn't change the boilling point significantly. It's the pressure in the system that raises it. If the pressure cap is working correctly it shouldn't be evaporating off because the whole point of a separate header tank is that the coolant doesn't circulate through there so never gets very hot. If you're losing coolant you might have a leak at the water pump or, worst case, a blowing head gasket.

[Blagger89]

I've had Head Gasket blow before, in 2009. Ended up having a new engine put in instead, since then ive done under 40,000 miles on it so I would hope that it hasn't gone. That, and RAC and I have checked for head gasket being blown and have no other visible signs. No white sludge in oil and no debris in the coolant which happened when it blew before. I'll check the water pump for a leak tomorrow/Tuesday but theres no signs of any leaks anywhere.

[artscot79]

the coolant wouldnt evaporate that quickly so thats not the issue but as said if the pressure caps faulty then the boiling point will be considerably lower than it should be so for the sake of a tenner ide replace the cap first its also possible you have an airlock try the heater on hot and see if it stays hot or not or goes hot and cold an old trick to get rid of the airlock is to let the car idle with the cap off for a good ten minutes or so

[Blagger89]

Afternoon, I do have a replacement cap on its way, should be with me tomorrow. Taking it to a garage round the corner to double check its not the Head Gasket. Once thats ruled out I will take off the radiator and try flushing that through.

When idling with the fans on full and max heat I only get cold air, the hot doesn't kick in until I start driving it. The hose furthest to the right (when looking at engine) is normal temperature until driving then it goes hot. And the hose on the left stays normal when idling and gets a little warm after driving.

I have read somewhere it could be the PCM needs recalibrating?

[mjt]

When idling with the fans on full and max heat I only get cold air, the hot doesn't kick in until I start driving it.

That sounds like an airlock. Do you get the heat if you race the engine for a few minutes?

[Blagger89]

Yeah I drove round the block and about 30 secs/minute into journey the heaters started blasting heat out.Then when I pulled back up, opened bonnet the hoses on the right were ridiculously hot and the left one was slightly warm.

[mjt]

It does sound suspiciously like an airlock. Basically you are not getting any flow until the pump runs fast enough to develop the pressure to overcome it. That could also explain the apparent loss of coolant as some air has been dislodged and the space filled with coolant.

[Blagger89]

Righto, well I've got a new cap en route so tomorrow I'll pop that on and then try getting rid of the airlock. I've literally left it running for 20 minutes earlier and it doesn't seem to have budged. But then again, the cap does seem loose as there was a very faint hissing from the cap when I turned engine off.

[Blagger89]

Got it back from garage today, failed a block test. Said that there was gas in the coolant which suggests head gasket gone or a crack in the engine block. Doesn't seem worth repairing so will be ringing a few scrappys to get some money for it.

[artscot79]

its very rare for a ford to do that to be honest none the less it would appear youres has done

[Blagger89]

Well the plot thickens. Put the new cap on this evening when i returned from my second job (car was parked at the garage next to my other job). Let it idle for 20 minutes while sorted some stuff out, then drove it back with heater on max and on max fans....got up to normal temperature and had no issues driving back even getting up to 50mph in 3rd. Revs all seem fine and no other ill behaviour. Will take radiator off tomorrow and try flushing that clear through, checking all hoses, and re-filling with fresh coolant. Will then run around the neighbourhood and see what happens from there on in.

If it does persist, I'm picking up a 52k L reg 1.2 Corsa for £200 of a family friend to have as a go to car for work etc, and will slowly strip the engine off the focus and try to see if theres any damage.

The mechanic said it looks like a head gasket failure or cracked block? But wouldn't confirm unless he took it all apart which is money I can ill afford to do as money is required for a working car to get to work. I will continue this as I just don't trust any garages in the area due to four previously not finding an oil leak on my car only for the engine to blow doing a ton on the motorway due to.....lack of oil!

[jeebowhite]

dont write her off just yet, are you willing to replace the head gasket? cracked block is rare, and I mean... RARE!

the main cause of a cracked block would be a serious impact, you stand less than a 1% chance IMHO of having a cracked block!

[Blagger89]

I dont think it would be a cracked block, like you said highly unlikely and I'd be pretty aware of it happening. Head Gasket? Could well be, I know I have a leaky valve cover gasket as I went to change the Spark Plugs and there was a little puddle of oil around each plug.

It's up on eBay at the moment, if it doesn't sell, it's going on AutoTrader. If that doesn't shift it, I'll be looking at taking apart the engine top down to get to the head gasket and seeing the likely damage on that, if it doesn't require skimming (not sure if I'd know) I could quite happily buy the part and put it back together and revive the car.

My other option is to shift it to a used car dealer and part ex it for another car (possibly an 04+ Focus model).

[jeebowhite]

Could be worth a shot! do let us know how it goes though!

[Blagger89]

Sorry to bump but I have a disappointing update.

Cars been on AutoTrader and eBay and failed to shift as yet. Had a few enquiries but people can't seem to understand that the cars not taxed and can't be driven away.

Anyway, been keeping the car active and turning over the past 2 months with no issues and driven round the block a few times and its always seemed fine. However sometime in the past two weeks its officially shown signs of a HG blowout and the oil in the cap and dipstick is milky coloured.

As I can't seem to shift it I'm going to start stripping the engine, and have a look at replacing the HG myself. Got my Haynes manual and plenty of spare time and its not like I can do any more damage, the cars bust as it is!

What I want to know is how can I tell if the HG/Pistons are warped or need skimming. As the cars been fine running I'm hoping that nothing is warped as the previous HG failure the car refused to work and thats when it was warped previously and cost alot to repair!

Any info on the process would be great!

[jeebowhite]

Dan, with regards to the no tax so cant drive, its not your problem!

If you declared the car as OTR, then whilst its in your name, its your responsibility to keep it there. If Someone wants to buy the car and drive it home, once they sign the V5, then its not your problem,. if they want to drive and get nicked its there choice.

Not that I am condoning this action, but if you do want rid of the car, then dont let this stop a sale. If they want to take a risk, you need the money in your pocket....

[Blagger89]

well thats true, either way the car can't be driven due to the HG actually going now and the oil all peanutty/milky. Such a shame.

[jeebowhite]

if you have the time to fix it (and the patience) give it a crack, you have a car worth nothing at present, so you cant exactly break it and reduce its value to nothing!