Hi guys, this is a weird one so i thought some of you guys might know whats happening

Basically my RS overheats when i switch the engine off, when driving along the gauge stays under halfway (in the 'NORM' section) when idling it does go up above halfway but the fan cuts in and cools it down.

Problem is when i switch the engine off the gauge goes up towards the red (still in the NORM section) and the water starts coming out of the overflow, plus theres like a boiling bubbling sound coming from the within the reservoir

I have temporarily 'cured' the problem by connecting the cooling fan on a permanent live straight from the battery so that it cuts in as normal and when i switch off now it'll stay on to cool the engine down

Any ideas guys? the engine has been rebuilt with all new gaskets etc, oil and water dosent appear to be mixing either

 

So you mean after a run with the ignition on (engine off) the temp gauge rises?

If the engine is off it can not be creating heat (unless its on fire), it could just be the coolant coming from the turbo which will be very hot, entering the top hose/thermostat housing (where the temp sensor is) and causing the gauge to go up.

Not something i have really noticed on my Escort to be honest and i cant check now as i have the engine out.

 

Ignore the temp gauge after you have turned the ignition off.As above,engine will not be creating heat when switched off.Will go up a little bit when the fan stops with ignition.But nothing to worry about.

 

well if you get concened but well i dont think any body really would but if you want piece at mind try flushing the rad full sys flush! well if it still does it well no problems!

a lot of older fords do it
my mk1 fiesta 950 did it too !

never did any damage!!

rob

 

Ok thanks guys, will just keep an eye on it, am thinking maybe ive overfilled the system a little bit and its pushing the excess water out

I wouldve been majorly concerned if it was overheating when running but it just strange that it does it only when i turn the engine off.

 

Sounds like the cooling system is not keeping its pressure, and since you're not looseing any coolant (are you?) it's quite likely to be the expansion tank cap.

 

Yeah, but the water pump doesn't run anymore. The water pretty much stays in the same place and can in some hot spots even start to boil.

My gauge usually climbs up to 3/4 after the engine is turned off. On really hot days (and when I'm not in a hurry :P) I turn the engine off, switch the ignition on and wait for the needle to rise. Once it's over 1/2 I start the engine again and let it run on idle for a few seconds in order to pump the water around again.

 

Its not an un-common thing for the temperature to rise, obviously there is no heat being created but for those of you that stick by that view are somewhat blinkered, there is still heat in the block and turbo, but no water circulation so the temperature is going to rise as the least of the heat disperses into the cooling system.

Not too sure what the answer could be for you though, i know quite a few people with RS's and they all seen to run ridiculosuly hot and get to temperature quick, mine is the complete opposite and runs extremely cool

You sure the radiator is in a good state of repair?

 

Grey,

heat wrap the turbo, manifold and down pipe mate. Makes a "BIG" difference!!

Very cheap to do aswell!!

 

And crack them all in the process....

Overfilled by the sound of it - it will bubble when off - water coming from the turbo. Nothing to worry about. Ignore the gauge - it doesnt work with ignition off.

 

Right ive have had another look today the temp still rises when i switch off (fan cuts in) but no water comeing out of overflow and no bubbling, water level just on the maximum mark when cold. Will just keep an eye on it

The rad is brand new and so are the hoses so there shouldnt be any problems with the system

Is there a difference between a standard 16i expansion cap and the Turbo one? ie pressure rating?

 

The coolant will still circulate to a certain extent even if the pump is not running. Hot water will rise in the engine (the same way hot air rises) and fall in the radiator. There is a name for this but i cant remember it off the top of my head.

 

mine used to do that, the water in the turbo was boiling and the car would sit there bubbling for a minute

dont sweat it, just put the right amount of good coolant in and if it bothers you (like when i would come home late and not wake the lil un with a boiling car) i'd drive the last mile heaters on full and fans flat out, never did it then unless id been gunnin it, my turbo use to light up the ground under the car after a bypass top end run tho

 

convection ?

 

convection currents is possibly the phrase

 

Thats one term for it but there is another when relating to a fluid flow, its "Self Something"

 

"Self Circulation"?

 

Thats the one