HI
My new turbo was blowing blue smoke all the time .I picked it up cheap because the shop told the owner it needed a new turbo I uncloged the turbo equivelent of a flame trap with a nail and repaired a break in the small vacume line, no more smoke passed emissons fine.
it seems high crankcase preasure will force oil out the turbo shaft because it can't fall back into the oil pan too much preasure