Hi.
hot or cold if the turbo seals are faulty you will see smoke ,let it idle when hot for around 5, mins and then give it a few heavy revs and check for smoke if so 90% certain turbo seals, if when u park the car and restart about 10mins later u get a little smoke probably vavle seal, oil draing back thruogh valve seals to cylinder, and then being burnt with fuel, if just from cold maybe the valve seals as (above )overnight oil drained past seals to cylinder then smoke on startup.

Dave,