You have white smoke and heavy fumes when your car warms up there is no oil in water and visa versa its a BMW 750il you done an oil change which you put in 10x40 oil 7 quarts which you were told that?

Check the dipstick and find out if there is too much oil in the engine. Never rely on what someone tells you when filling a liquid in an engine or transmission, use the dipstick. If the oil is not overfilled, the valvestem seals may be going bad. These prevent oil from dripping down the valve stem into the cylinder.