have you checked the radiator for blckages ? also does the fan kick in?

 

The fan does kick in, yes.
Also I'm unsure weather the radiator is blocked or not, I assume its OK, I can easily pour water in the expansion tank and it will come pouring out the bottom drain hole. If I use a hose pose to add a bit more pressure, the water squirts out all over the place with greater pressure. So either I thats what you mean for blockages or I've not checked it.

Jason

 

Well flushed the heater matrix out, installed a new heater control valve, heater works great now, just gotta keep an eye on the engine heating up.
Turns out I also didn't screw the expansion cap on tight enough, its very tight now and seems to hold the pressure much better now.

Cheers