white smoke

[hhow55]

White smoke is either unburned diesel, or coolant. Is your coolant level going in your reservoir, if so, this could be your problem. But i tend to believe you may have an injector leaking very badly, since your motor is running very crappy. I would try doing injector cut out test using your insite. Rawze has a video on this. If you have a temp gun, take a temp reading, on the exhaust manifold at each cylinder. The one with the lowest temp, will be the leaking injector.
Good Luck