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1.6 Focus overheating - possible causes?

T reg 1.6 focus. 90k on the clock.

Heading out the other day 3 miles from home temp gauge goes to max and an orange warning light comes on (looks a little like a cog or a splash with an exclamation mark in the middle). Dive to hard shoulder and stop. Temp gauge drops to about 3/4. Trundle along a little and pull off next to a ford main dealer.

Expansion tank is virtually empty...

Top it up and wait 30 mins. Start car. Leave it idling and after 5 mins or so temp gauge goes sky high again *but no more warning lights*. Pull into the main dealer and ask if anyone could have a quick look.

"Sorry, too busy this week". This was thurs. "We could have a look next wednesday. Book it in" :-(

Go sit in McDonalds and think about it. Go back to now cool car and check water again. Attempt to get it somewhere more helpfull than ford and during my trip across town it is fine. Since then I have done 400 miles without a problem.

I know the coolant level was fine the evening before it overheated as I checked it along with oil etc. I didn't remove the expansion tank lid so the chances of it being loose are slim. Never had any other problems with the car overheating before. Bit reluctant to rely on it at the moment though :(

Any ideas? The only suggestion that has been made so far is that the thermostat stock closed and the engine overheated and pushed the water out. This then became unstuck as it cooled and the problem went away. There was no sign of steam and no obvious sign of water leaking from anywhere. No sign of steam from exhaust either. about a litre of coolant vanished via a route that has fixed itself :-( Also, it seems a little odd that I got a warning light the first time but then not again (I guess it maybe that I was being a lot more carefull to ensure it didn't get quite so hot the second time and it never triggered).

Does the thermostat theory sound plausible?

Cheers!

Darren

Reply to
dmc
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There have been incidences of the CHT (cylinder head temp) sensor wiring chaffing on these early cars- there is a TSB to re route the wiring, and a modified CHT sensor wiring loom too- to be fitted to cars where chaffing is noted, and / or where misfires are reported.

Also there have been some incidences of cracked heads on the 1.6 engine, so I would keep a very close eye on both the temp gauge and coolant level in the meantime. If it is using coolant and you dont have any external leaks, then be ready for the worst!

Tim..

Reply to
Tim (Remove NOSPAM.

Hmm.

I assume there is no way that this could cause the loss of coolant though?

:-(

Thats what it odd. It used about a tank full of coolant on one run up the motorway. 400 miles later and it still hasn't used a drop. Is the sticking thermostat theory unlikely then? (sounded just about plausable to me but maybe I'm hoping its something simple!)

Assuming the worst, what sort of money are we talking for a head for this? Its the older zetec apparantly - S not SE I think.

I should have flogged it a few months back as I had planned. Having stuck

4 new tyres, a wheel bearing and a cambelt on it 8k back I'd rather not get shot now :-(

Cheers,

Darren

Reply to
dmc

No, because the CHT on these engines fits in a blind hole- i.e. not in contact with the coolant.

The SE is only available as the 1.7 VVT as in the Puma. You have thge Zetec-S. A stuck once thermostat is a possibility, especially if it hasnt used any coolant since, as is a faulty or loose pressure cap. I'd have a good look around for blue or red deposits at hose ends and keep a careful note on the coolant level over the next week or so. Was the water pump changed when the timing belt was? If not it could be leaking- they sometimes will when disturbed by a belt change.

Tim..

Reply to
Tim (Remove NOSPAM.

I was thinking more in terms of it confusing the ECU to such an extent that it cooks. Now I think about it I can't see how that could work so I'll forget that theory :)

Ah. Fair enough. I only mentioned it as whenever I try to order HT leads etc from the dealer they attempt to sell the wrong ones (too long). "Its what the computer says for your reg no mate" etc etc

Yeah, I have been watching closely. Nowt obvious. Cap seems ok and was still tight.

No, the pump wasn't changed. I did think this but I can't see any sign of a leak nearby.

I think I'll attempt to convince myself on the stuck themostat theory - seems the least scary. (May well stick one in it in case). I'll keep a close eye on it for the time being.

Cheers (for putting my mind partly at rest!)

Darren

Reply to
dmc

The pump has a plastic impellor on a steel shaft... the impellor comes adrift from the shaft and therefore the pump has very limited pumping ability..... have changed at least 3 of those on Zetec S & E engines.

JK

Reply to
JK

Spoke too soon :-(

40 miles this morning and it has gone from max on the tank to 1/2 inch below min :-((

Still can't see where it is going. Booked it in at one of the few garages in Canterbury that I trust - snowed under till 8th June :-(

Just have to nurse it till then and hope I guess. Maybe trade in time has come...

Darren

Reply to
dmc

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