thank you for your help, i found the answer in another thread... after all of the buggering around ordering parts, it ended up being the radiator cap.. *shaking my head* well i was told at the start of the investigation that there is a flow chart and guess what, the second item appart from the coolant level is (drum roll) radiator cap... somehow i missed this.

was checking coolant and topping up every couple of days, now is two weeks since i changed the cap and no change in coolant level.

thank you.