got a bit of a problem. the car cools fine when driving but when i stop and turn it off it boils like a bastard, plenty of air there aswell.

i have tried taking out the thermostat but that made no diff, but now my fans have stopped working.


help help help please

 

if the fans aren't working put a new rad fan switch in the radiator(pull off the wiring connector and bridge this with piece of wire to check the fans)and fit a brand new thermostat.
when you start the car after this leave the expansion bottle cap off,and put the heater on full with the controls to warm, and try squeezing the top and bottom rad hoses to move any air that is trapped.

 

i will give this a go, but im worried about the amount of air in the system. ne ideas on that

thanks for your help

 

https://passionford.com/forum/viewto...383&highlight=

coolant flow, any ideas

 

Hi Boost Mad,
Get your cooling fan problem sorted out first, then see if you still have a problem? bearing in mind if you have a RS500 style intercooler this does impose higher demands on the cooling system and the fans could be cutting in and out fequentl.

You say whilst driving the car seems to be cooling ok, then when you stop it boils over. Does this happen after you have shut down the engine? or whilst it is on idle? Does it boil over with the header tank cap on or when you remove it? What happens if you start the car from cold give it a few revs then remove the cap? Whilst driving is there any signs of white smoke or excessive steam out of the exhaust?


Just for information, the water returning to the header tank from the turbo will often boil for a time after the engine has been stopped due to it absorbing the high latent heat from the turbo exhaust housing this will occur through natural convection as the heat travels upwards and this will cause you to have air in the header tank, this doesnt mean there is a problem with the cooling system though!

CheeRS, Mike.

 

right,

the boiling happens when the car is off, or when it has bee idling for a while ( 5/10mins after a drive ).
it boils both with the cap on and off.
if started from cold all is fine ( all bar a little oily blue smoke )
no smoke from exhaust.


just a thought, although i dont have a rs500 cooler yet, when i do get one i thought about getting a turbo cooler aswell. now, i no these go after the turbo but befor the header tank so why are they called turbo coolers? has anyone plumbed one in so that they go befor the turbo

thanx for your help

 

Hi Again,
the fact that the car cools ok whilst driving suggests that everything is ok in regards to flow around the coolant system. The car would overheat however if left on idle without the fans working.
With the boiling after the engine has been turned off could well be what I mentioned yesterday about superheated water making its way back to the header tank from the turbo, mine does this all the time. To give you an idea how hot this is the exhaust housing gets up to around 650-750 degrees C in normal use if you pedal really hard expect around 850 + degrees C. Where the stainless water pipe runs over at the top front of the cam cover I have had the rubber insert of the retaining clip melt on several occasions!
I think a turbo cooler is a good idea, I understand that this can make a difference of around 30 degrees C to the overall cooling system but putting it before the turbo would not work as efficiently as the water needs to be cooled after the turbo not before. A turbo cooler will not however cure an existing overheating problem, it does obviously add volume to the coolant system though.

CheeRS, Mike

 

another thing to check is the fuse box! the cooling fans if on a lot can cause the overheating popping of the fuse in the fuse box and a common problem for cossies! The fuse box plastic can melt due to the heat check this as well!!

Nick

 

cheers guys

 

Hey Boost Mad,
is that actually your cossie in your signature?
Also where in sussex r u?

 

my fuse box melted the fan fuse and the relay had to get a rewire for this be careful cos its expensive but its a cossie

 

that was my old replica y?

 

Disconnect the water cooling from the turbo. and blank it off, the turbo instantly boils the water. I no loads of cossies that have run for years with no water through the turbo, the oil does the job.

 

woudl still like to no whcih way it flows please

 

stupid as this sounds try the cap on ya header tank had the same problem with mine last year thats wot it was for 6 quid its worth a try