coolant system pressurising badly help
 

hi all the coolant system keeps pressurising badly all the time i drive it i have done i have tested it for to see if the head gaskets have gone and they were fine. i only have to drive it 500 yards and the pipes are rock solid hopefully one of you lot have come across it and can help me

Could it be thermostat fooked?

does the coolant expansion tank behind the nearside headlamp have bubbles in it?

iv replaced it and checked it before fitting it i have been told it may be the turbo

yes now and then