Cooling issues mk4 golf

Right the problem im finiding is that once the car is up to temp and then is switched off you can hear the coolant bubbling away in the header tank, I have checked for all the usual leaks and that replaced two hoses and it still does it.

Any ideas?

header tank cap?

yeah i meant to say i fiftted a new one the week before last, maybe just a dodgy one then?

Lupton_20vt wrote:

yeah i meant to say i fiftted a new one the week before last, maybe just a dodgy one then?

is there a lot of pressure in the system if you remove the cap?
cos this sounds just like how my ex's corsa went when the headgasket had gone.

the wifes cabby does the same, you can hear it hissing, i figured she had a dodgy cap too

whatalotafun wrote:

Lupton_20vt wrote:

yeah i meant to say i fiftted a new one the week before last, maybe just a dodgy one then?

is there a lot of pressure in the system if you remove the cap?
cos this sounds just like how my ex's corsa went when the headgasket had gone.

cheers for that and the call mate yeah i doubt it will be the headgasket as it was changed 6 months ago

You need to pop over mine real soon chris anyway, let me have a butchers at it, I'll check out the head gasket for you, probably the thermotwat anyway, they are prime suspect for this, even if you changed it recently they are very prone to going.
I'll test the expansion tank gas all the same.
I'm home all day today if you want to pop over, sick boy.

oi im better now-ish

Found out what the issue was, a plastic connector below the header tank had cracked with age and only leaked when the system was hot and under pressure