Bro, do make sure that u pour the water in the proper way; start the engine, open the radiator cap n loosen the bleeding screw..only then u can pour the water into the radiator until u will be able to see the water or coolant coming out from the bleeding screw..then tighten the bleeding screw before tightening the radiator cap..yr coolant should be adequate for the radiator this way..FYI, bmw raddiators fins are horizontally positioned, so refilling the water or coolant will take some time..this is what my mech told me..correct me if i'm wrong..tq