Well, I had a similiar problem and it was the bearing on the turbo going bad. It was caused due an oil line that goes to the turbo kinking and caused the bearing to go bad letting oil through causing a similiar smoke situation to what you have.
2012 F-250 FX4 CC SWB 6.7 3.55 e-locker, Oxford White
2006 F-250 4x4 Crew Cab 6.0L Auto. Lariat, RBP 4" Stainless Exhaust, Weld Wheels, Nitto Terra Grappler Tires, Autometer Ultra Lite 2 Guages, Greddy Turbo Timer, Line-X, Access Roll-Up Cover. (SOLD)
2004 Honda CRF 450r. FMF Powercore 4, FMF Power Bomb Header. DID Chain. Too Fast.