Black smoke is over fueling and running rich - when turbos go they tend to chuck out blue / white smoke.
The turbo could have seized though meaning air is finding it harder to get to the engine but fuel is still being thrown in.
Turbos (the inlet pipe) also tend to suck the breather gasses from the crankcase as they create a vacume in the inlet, though if you have breather problems you normally gets blue / white puffs on the gearchange.
Get the inlet pipe off over the weekend and check for play in the turbo shaft
There should be no in and out movement and 1mm up and down movement - max