It was actually caused by the breather pipe from the cam cover being blocked off, Reason being it has a powertec induction kits and where the breather pipe fitting is welded on the filter is actually blocked from the inside by the mass air meter once fitted and tightened up.

This caused pressure in the cam cover, released the oil cap and pressure come out then noise stopped, tightened cap and couple of minutes running and squealling noise again!!

All sorted now though. give it a service also and drives great now.. Not sure wether to sell it or keep it now as been thinking about a Impreza, Leon cupr R or Octavia vRS hmmm