Update on this post for anyone who is interested. I fixed the problem
Replaced radiator with an aftermarket one $350 AUD including postage ( suspect the original one was damaged as had coolant stains, not alot but some )
Bought a BUDS 2 unit with a 1 year dealer $1000 AUD
went thru the intake area of the engine, top of cylinders
replaced all the leaking coolant o rings ( the original rubber around metal washer ones )
used normal o rings and tightened them ( originally they were too loose IMO and causing the leak and air in the system )
bleed the coolant system, i found having the system just get to temp and fan cycle twice did jack all to get the coolant thru the system
take it for a blat then check the level once cool, did this twice to get.
plugged in the BUDS and flashed the system
I only had one fault/error before this work, the 02 sensor and a over temp message ( alot of them )
After the flash there were no errors, I will replace the 02 sensor soon tho
Its been 2 months now and its been driving well, no overheating issues
getsome