That doesn't sound good. You can try all the normal stuff (cap, thermostat etc), but I'm leaning towards a BHG.

time for V6!

Im waiting for my mechanic to get back to me about the extent of what has happend. If it going to need rebuilding, i guess i need to get moving along with rebuilding the GTE thats sitting in the garage and just do the conversion.
 
 

How much more do you have to do with the 3sgte to get it running?

It has a long way to go unfortunately. I have been stripping it down over the last month. Need to get parts and have her machined/rebuilt. Once thats done its down to getting everything else such as exhaust mani, turbo, fuel rail, intercooler etc since all i have is a long block and then i just need all the conversion parts gearbox, drive shafts/hubs and turbo loom. 

Deco

Thanks Rob for such a quick reply.

Thats was my best guess but am unsure as it was just such a sudden issue. I guess its about time i had a mechanical issue in my 10 months of ownership haha.

With this over heating exercise i also found that the oil that i thought was coming from the gearbox that i was talking with you about earlier tonight was in actual fact coming from the purge tank over flow. Not sure if this has something to do with the over heating issue i have.  

 
Have you opened the bleed valve behind the spare wheel when filling the coolant?

Radiator cap is one thing, but also the plastic filler neck on the cooling system can weather and let air in, usually at the top of the first turn.

The way i gauged that it was about 2L lost was by how much i put back in before it over flowed.
 
you may have lost more than 2 liters, as it normally takes a long time to properly fill her up and bled. then u kept driving it with not enough coolant and air pockets in d system. ur lucky u werent driving in d freeway as it will not shut off untill ur head is cooked. i popped one of the cooling system hose once and over heated, shut d motor straight away lost most of the coolant. lucky caltex was round d corner, n lucky i have sum hose in d car that i used to temporarilly rigg her up. i filled and bled the system  with tap water for more than 4 hours on d side of hoddle street on a rainy night.  (emergency fill and bleed, just so i could safely drive the car home and perform a proper flush and bleed)  
blown head gasket is d least of ur problems, blown cooked head is d worst case scenario

Dudeman

Have you opened the bleed valve behind the spare wheel when filling the coolant?
 

 
No i didnt touch it, just filled it up and turned the engine on for it to suck it through and then refill again. My father and i didnt realise there was a bleed valve and that it needed to have the bleed valve open when filling her up. Just thought it was like filling up any other car with a self bleeding system. 
 
 
 

ah, the wonders of the world's most complicated cooling system.