TD5 lost power and lots of blue smoke

Hi all,
Just driven 50 miles in newly aquired disco TD5( 2002 facelift ) and all was well until pulling onto a dual carrigeway then there was a knocking from the engine sounding like loud tappet noise then on an uphill lots of blue smoke, pulled into layby for AA recovery, he suspected the turbo but having checked the impeller it looks ok, very very low oil level in sump though after being serviced the previous week, could it be injector seals ?
Appreciate any ideas as the knocking sounded expensive, by the way no warning lights on the dash.

Cheers Tony

Could be failed turbo oil seal, exhaust side, you wouldn't see anything by looking at the impeller, but it would be obvious from the exhaust side if you whipped the turbo off.

Hello welcome

Thanks for reply, will check turbo but small crack in head as well, under guarentee thank goodness.
Update soon

Cheers Tony

Hello and Welcome