X5 E53 ENGINE OVERHEAT

[jakpan2004]

Hi, just bought my fairly use X5 E53 3.0i and it started overheating from day 1, I have changed the Expansion tank which was leaking from the valve, fan clutch I discovered was faulty and was change, Thermostat housing was leaking and changed. I have bled the cooling system according and the engine is still overheating. What could actually be the problem any assistance will be appreciated.
I even had to remove the thermostat from the housing hoping the hot climate may compound issues, it only slowed down the heating time against when it was installed. The radiator is not leaking and it was flushed. will there be a difference to change the radiator from single vane to double vane