Taking the thermostat out is what ive been advised to do and will do tommorow seeing as ive smashed most of the plastic trims that were in the way out the way (undertray etc) i can take the stat out in 2 mins tops.

Basically when its cold the water level in the tank drops, as it warms the water level rises, add revs to the situation and you get a mini eruption of boiling water.. the car makes a load of burping, farting, groaning, creaking cracking noises for the first 2 minutes after its been switched off really does sound like air lock and a major one at that..

As for taking hoses off, i can take the ones off the rad, the waterpump, the stat housing, and a few in around the front/side of the engine but the ones at the back seem impossible to get out with taking the inlets off ?

Yeah ive been bleeding it with the cap off and the heaters on full on hot, didnt work.

Also been told the pressure from when the pump failed could have knackered the header tank cap?