if gasket is blown it could be pushing exhaust gas into water system and replacing water--so allowing it to boil in head,
not convinced you got it bled correctly
even if cap is only holding half the pressure removing cap when hot will still result in the water being chucked out
anyway a new cap and thermostat is always a good thing when replacing gasket ,if it is that --overheating may have damaged either or both

cars been fixed it was the head gasket it had gone between 2 water ports all done now though running like it should again had new cam belt and stretch bolts done aswell

thanks for all your help guys much appreciated

Welsh, epic bump, would it not rise above halfway if the fan was not cutting in or manually operated i.e on a switch?

Sent from my EVA-L09 using Tapatalk