I have a problem with my cosworth, i have only just got it and every coulpe of days it with overheat really quickly, when it does the cooling system is pressurised and the top hose nothing but steam in it and the header tank is full to the brim. If i vent all the steam off it empties the tank and i can fill it again whilst bleeding it from the top hose. looks to me that it may be an airlock somewhere but i was wondering if anyone had heard of this before.

 

Could be a head gasket gone

 

You either have a leak somewhere or the headgasket has gone! It could be the water cooling on the turbo bearing.

 

most likely the headgasket is gone m8

but you could as said have a leak from somewhere, on one of my rst's I had a similar problem, and the only way I found the leak by accident.

I started it on a cold night and as I drove down the road I could see steam coming from under the bonnet, so I pulled into a petrol station (under the lights) opened the bonnet and looked for where the steam was coming from.

The water return pipe (metal pipe on the turbo) has a hairline crack in it where the bend was and was spraying a fine jet of water onto the turbo housing and burning it off, so if it hadn't been cold would never have found it.

When I took the pipe off there was no sign of it being cracked either, until I pulled it apart very slightly.

 

thanks for your help, i was hoping that no one would say the head gasket, is it possible to check this without taking the head off? If it is the headgasket is it fairly easy to change? finally if i need one do i get grp a or multi layer, as i am planning to go to stage 3 as soon as this is sorted

 

If you are planning on going stage 3 i would recommend a Mountune WRC 4 layer headgasket but they are Ł380--do it once, do it right

 

If you have got a leak and its not obvious (water gushing out of a split pipe) it could be your heater matrix that is gone. It will leak down into the foot well but it can take a while for the carpet to appear wet as gets soaked up by the sound deading before it spreads into the carpet.

 

Could be a blocked rad, my mates did this and had to get another one

 

I think a new rad is first on the list, is it worth my existing one recored or just buy a new one, but i am tempted to try and find a motorsport place that is open on a saturday and go to stage 3 etc this weekend.

 

head gasket or thermostat not opening

 

Until your want to port the head, go low comp etc as u know its going to happen lol

 

is it overheating while driving along normally, or in traffic? if it's only in traffic, are you sure the cooling fans are working? Classic cossie problem, melted fuseholder in the fusebox

 

It will run fine for a couple of days, (fans on permenantly) and then normal driving, today at about 80mph on an open road within a couple of minutes its at the top of the gauge, normally it runs just below the start of norm on the gauge

 

avengerpenguin,

TBH we are all speculating on what may be wrong.

I'ts worth getting your car to someone that knows Cossies well, to give it a check over. I would reccomennd a leak down and a compesssion test as a first course of action. It may be that there is not a lot wrong after all..then again.

I see that you are in Bristol, I am sure that there are one or two peeps from Bristol RSOC that could check your car over, or at least reccomend somewwere local to you that knows what they are doing, and wont try to rip you off

Maybe change the title of this thread (EDIT) to "Bristol/Glos peeps Cosi help needed please"

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mine blew its top due to a failed thermostat.... dumped all its water as i was going down brunters... with the fans on it was fine

 

well you could try powerstation in cheltenham for a check over, they won't have any stage 3 bits instock tho

 

Also,

Just up the road in Thornbury is Interpro - it may be worth popping down there tomorrow and speaking to Dave or Simon, they may be able to have a quick look at your engine and advise/reccomend re the over heating and tuning aspects

 

BTTT for avengerpenguin!