How do you know if a diesel engine is burning oil it has been smoking since I had the oil changed the smoke is white but smells like burnt fuel?

The main part of diesel fuel is kerosene, which produces thick black smoke, and gives that smell that is commonly associated with diesel. most likely if it is white smoke, it is antifreeze, if it has a blue tint to it, it is oil. the smell of burnt diesel is rather strong so it could cancel the burnt oil smell, or on the other hand it could be coolant, because burned coolant doesn't have a strong smell. I would check your coolant and oil levels, and check your coolant for having oil in it.