Have you left it with ignition on, fan on hottest setting, fan speed on lowest and slowly poor coolant in until it come out of the top bleed screw?

 

Yeah did that its odd i got it so the water was flowing from the hole, took it for a drive the heater ok then the low coolant light came on when i checked the bottle was empty, also the bottom hose is cold and the top hose red hot, but still not managed to get any water from the bleed valve on the oil cooler do i have to have both open ?

 

forgot to put ive done the same thing but the water is getting sucked into the hole instead of blowing out !!!! doesnt over heat that was with the engine running

 

N42 engine is notorious for bleeding, I've just gone through the same trouble as you! Basically, top bleed screw is higher than the expansion tank, so you'll never get water out of it by normally pouring water in, you'll need to either jack the front of the car up, to bring the expansion tank above the hight of the bleed screw or find a funnel or cut the end off a bottle that you can stick in the tank so you can over fill it with water, either way, you need to get the water level of the tank above the top bleed screw. Probably haven't explained myself too well.

Also just want to re-itterate that you should bleed it with the ignition on, but engine off.

 

Explained perfectly did all that went for a drive when I got back saw mist coming from under the bonnet as its so cold tonight lol it's the connector on the hose that connects to the oil cooler it is hissing and when I wiggle it was dripping coolant so il see if you can get this connector or a new o ring