Hi all,

Zetec cooling is no doubt a very common subject on this forum......

My 2ltr Zetec Blacktop runs very hot which seems to be the norm in these cars, runs better with the thermostat than without tried both ways, the fan is contolled via the sender located in the top of a recently refurbished radiator, anyway would like to fit a switch which will control the temp range of the fan, ideally I would like it to come in at about 85 degrees.

Anyone know where this can be sort, I have seen the ones which run from a capillary stuck into the top hose or radiator stack...... dont really fancy one of those when I have a sender already located in the header of the rad...

Please help

Kind regards Pete

The standard polo one comes on at either 95 or 102 degrees depending on which pin you use? Just though it may help for you to know.

Cheers

Rich

[Edited on 31/8/11 by RichardK]

Cheers Rich, but not sound thick, but what do you mean by " which pin" what is meant by pin..... Cheers Pete

Use a lower temp opening thermostat, I think Burtons do an 82 degrees or modify a mini 74 degree one,
This helps enormously
Duct the radiator and consider a bigger (thicker) radiator, our sevens always run hot but for best performance 80 to 85 is prefered.

For a start what type of thermostat are your running ? and are you running a by-pass hose in the system ?

The problems of overheating with certain type of aftermarket water rail and remote thermostat are well known --- if you have one of these stick it on ebay and put the standard thermost housing on with a by-pass hose from the engine side of the thermostat housing running back to the water pump.

A by-pass hose is essential for two reasons: It circulates the hot coolant around the thermostat allowing the thermostat to get hot enough to open before the engine boils and it circulates coolant around the lower parts of the engine even when the thermostat is closed.
If you have a thermostat but don't have a by-pass connection the top end of engine will almost boil before the thermostat opens and the bottom half will run cold with the temperature see-sawing between over heating and over cooling..


An 85 degree fan switch is a bit of waste of time as it is well below the temperature at which the thermost starts to open, ideally you need a fan switch that cuts in just above the temperature at which the thermostat reaches full open but cuts out a bit above the initial starts open temperture of the thermostat --- ie on at about 95c off at about 93.

The way the cooling system is intended to work is the thermostat regulates engine temperature, the fan regulates radiator temperature.

Cant find a picture of my polo switch thats in my rad but this should give you an idea, 3 spade connectors on it.



Just choose one of the two outputs, or as mine is a 2 speed fan I connected both of them. Didnt realise that a lower temp stat was available so I maybe having a look at one of those as well.

Cheers

Rich

Qny diagrams available of he By-Pass hose?

Have a look through my gallery using the banner below to get an idea on how I did mine.

Cheers

Rich

You could also wire in a fan switch over ride switch I guess as well when things get too hot??

Simply a by-pass connects one of the smaller bore outlets on the thermostat housing back to the water pump inlet or bottom hose.

Often on kit car zetecs this is done by putting a Tee piece in the bottom hose.

Which is how mine is plumbed with the Raceline water rail (queue disbelief in some quarters with the call to stick a standard thermostat housing back on ). My Blacktop sits around 90 on the Motorway/ normal driving and the fan kicks in at 94 deg controlled by the ECU. I have a larger aluminium rad which has the T as described above and a 3mm hole in the thermostat plus a separate header tank.

[Edited on 1/9/11 by jeffw]

Thanks lads, I am going to check my fan tonight and contemplate the over-ride switch, definitely going to source an 82 degree thermostat, checked late last night and the it appears that the system does have a by-pass with TEE piece going into the bottom hose. The radiator was very very recently refurbished and upgraded with double fins to hold more water. I do believe the issue may lie with the thermostat which was also recently fitted, but was a cheap Jap make........... Cheers again

Well after trying various suppliers this morning, including Burton Power I can not find anyone who can supply me a 82 degree thermostat.... has anyone any ideas where to go to get such an item....

When you say its very hot, what is i running at exactly? Thermostat fan switch on mine comes on at 102 and goes off at 94. I wouldn't run it at 85 as thats a bit too cool for it.

This is mine HERE

Also...

http://partfinder.smpeurope.com/index.html?p=155&typeid=42&recordset=209&value=42

Agree re temp, engine designed to run with 93 stat, my fan too comes on at 100 deg and off at 95 and 10 years later still runs perfect.

Agree with last 2 posts but with a slight twist on mine. Had Zetecs now for almost 10 years, great engine. Always used a 88 degree stat in mine which was standard fitment in the Escort/Orion, don't think you can get them now, the fan switch in the top of the rad was from Burtons, switches on at 95 and off at about 90. If I had to get a new stat today it would be a 92 degree stat which was the later fitment, don't see a problem since that is the temp Ford set and The Mondeo/Focus was happy trundling for amny 1000's of miles at that temp. Would have to get a different fan switch I guess but will worry about that when the time comes. Running below the recommended temp may cause rapid engine wear, don't know why in reality, my x-flows always ran with 74 degree stats.

Paul

Hi

Ford ran the engines at those temps for emissions not best performance which is attained at a far lower temp.

Cheers Matt

quote:

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Originally posted by Paul Turner
Running below the recommended temp may cause rapid engine wear, don't know why in reality, my x-flows always ran with 74 degree stats.

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Well what can I say!

Some fantastic but very much conflicting advice, thanks to you all........ May have look at a 88-92 degree thermostat and check what temp the fan comes in, it appears that these engines do run hot and the gauge reading 95-102 is nothing to worry about as long as it is getting cooled correctly... Again a great response to an interesting topic, which no doubt will be subjected to this forum by some one else in the not to distant future............

quote:

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Originally posted by procomp
Hi

Ford ran the engines at those temps for emissions not best performance which is attained at a far lower temp.

Cheers Matt

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Pulled it all apart and checked everything over tonight, left the 88 degree thermostat in, ran it up, at stand still and the fan came in at 95ish and went off about 90ish, without boiling.......

Took it for a run out and the gauge fluctuated between 100 and 90, depending on the roads, seemed to incresase more on heavy acceleration and then dropped at slow steady running, fan coming in as described....

I feel a lot more comfortable and confident and the thanks must go this forum, the initial worry of the cat running to hot has been banished.........

Greenie

Worried me for a couple of years that temp went up on heavy acceleration but after 10 years with the Zetec and no problems I stopped worrying years ago.

Gauges arn't always the most accuarate of things after all.

Paul

Thanks for the extra reassurance Paul........

One final question, best position for the fan, the car came with it positioned behind the rad, is the best place for it or is it better in front?

Hi , i have my fan behind the radiator , works fine on mine , no over heating issues. some pics in my photo archive.

[Edited on 2/9/11 by dunk3]

quote:

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Originally posted by jeffw

quote:

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Originally posted by procomp
Hi

Ford ran the engines at those temps for emissions not best performance which is attained at a far lower temp.

Cheers Matt

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So what temp is best for performance then ?

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quote:

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Originally posted by Greenie
One final question, best position for the fan, the car came with it positioned behind the rad, is the best place for it or is it better in front?

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