Ford Fiesta zetec 1999 - Engine temp heats up......

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Car engine heats up when on long journeys and going 70mph, only way to cool it down is to put blowers on on full. Water and oil is fine was wondering if it was a blockage?

Thanks in advance
 
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possibly the thermostat stuck closed so water not getting to the rad...easy to replace..3 nuts if I remember correctly..plus a new gasket..while you have the thermostat out, shove a hose in the housing , take off the rad cap and turn tap on for 5 mins or so..this should flush the rad.
 
also it may be that the electric fan is not coming on.....start the engine and leave running until normal temp reached at this point the fan should come on..if not the wiring/fuse/sensor will need checking.
 
Ok I will look at taking out the thermostat. O so the fan should come on as soon as the temp reaches normal temp e.g when in the middle of thegauge?

I ran the engine before for about 30 mins the fan did come on eventually so dies this mean the fan is ok?
 
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If the fan comes on then its proably ok...I think there is a sensor fitted into the thermostat housing which controls the fan (one wire)..it may be a good idea to replace the sensor whilst you are replacing the thermostat.

Thermostats about £8, sensors depending on which one its is..£4-£14.

Failing these it just maybe be a blown head gasket...do you have to refill the rad frequently..?
 
Either the thermostat isn't opening fully or the main radiator core has a blockage on this one I think.....
The cooling fan normally operates only when moving in traffic - on the open road the through draught is enough to cool the rad.
John :)
 
Generally the water is fine I rarely have to change it, But I just did a few checks which I found on this thread

//www.diynot.com/forums/viewtopic.php?t=118427

First I did this part..
run the car engine

go into car and switch heater to maximum heat

put fan full on for 15 minutes

this will purge air out of system

Then I did this part..

another way that usually works is to run the car with the expansion tank cap off, and keep the bottle filled right to the brim.
When the thermostat opens water will gush out over the top of the bottle. When it does, turn off the engine and top up the bottle if needed.

This 2nd part suggests to me that the thermostat works so does that mean it is a radiator problem? And is it a big Job?

Thanks for the help guys
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If you have excluded the Fan/thermostat/sensor/head gasket then its likely to be a blocked or collapsed radiator core. Back flushing by putting the hose in the thermostat housing may remove debris. Other than that you may need a new radiator...have you checked that there is airflow to the rad..ie. no debris cling to the outside of the rad or plastic which has attached itself to Rad... changing a rad is not difficult...just bolts in place you will probably have to change a few things over like brackets and the electric fan..whats puzzling is the fact that its only overheating on long journeys...this probably points to the rad or thermostat..do the easy things first..either check or replace the thermostat prior to changing rad...take out the thermostat and put it in a pan on the stove as it heats up you should be able to see the thermostat open...
 
Thanks for all your help Im going away tomorrow but will do the final checks next week and will hopefully get to the bottom of this!
 
Could of course be the simplest of all and be a collapsed hose..sometime if they are old the inside frays a little this causes the pipe to collapse when is gets hot...worth a check maybe..
 
The Zetec engine - like most others - is designed to operate at around 90 deg C. This is the optimum temperature for oil lubrication, engine cleanliness and fuel economy. The temperature is controlled by the thermostat that either allows coolant to circulate through the main radiator or just around the engine block.
If the temperature increase above about 90 deg, the cooling fan automatically cuts in to cool things down.
To prevent the cooling system boiling and losing water, it is held under pressure courtesy of the filler cap on the top of the expansion bottle. The cap will start to lift at about 125 deg C - it is set to keep the pressure in at about 13 psi.
Fords are better than most here as the coolant continually circulates into the expansion bottle so air locks aren't common.
If you dont lose water, then you have a circulation problem caused either by the thermostat or the radiator core...its anyones guess which, really!
The Fiesta's main problem is the heater control valve - its electric and either fails or leaks badly...worth keeping an eye on it!
Lets know what happens!
John :)
 
I've had this before, and the key word from the OP, is at speed. It NEVER overheats while stood.

So therefore everything works, no thermostat blockage, no pipes blocked, no airlocks.

What happens is that the air pressure going into the car is greater than the electric fan motor can provide, thus the fan stalls, and car overheats, as the brushes are fubar. They work OK at low speed, but under pressure, they fail, and stall. Been there done that, got the book.

Mine was manual, by a belt, and the fitting was the wrong way round, I even fitted an additional fan to compensate.
 
Ok the next day after I did these checks we spoke about before especially the 2nd part.....

But I just did a few checks which I found on this thread

//www.diynot.com/forums/viewtopic.php?t=118427



First I did this part..
run the car engine

go into car and switch heater to maximum heat

put fan full on for 15 minutes

this will purge air out of system

Then I did this part..

another way that usually works is to run the car with the expansion tank cap off, and keep the bottle filled right to the brim.
When the thermostat opens water will gush out over the top of the bottle. When it does, turn off the engine and top up the bottle if needed.


I found that after opening the thermostat I now have a new problem, when I now start the car the engine is really strugling if I dont give it any revs if I just leave with no revs the engine will stall, this happens for quite a while until the engine is really warmed up.

So I dont know if this has stopped the temp rising at high speeds as I now have this problem and dont want to take to far. COuld it be the spark plugs causing this?


Mickymoody- so u advise to fit an aditional fan? is it easy?

Thanks again



Thanks again
 
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