check the inlet and output of the turbo pipes which has more oil in ?, this could either be your turbo as i thought it was with mine or a breather pipe,unfortunately it turned out to be the bores. how much mileage has it done? does it try to over rev, the engine could start feeding off the oil that is probably in the plenum chamber as well as the intercooler, first of all take the intercooler out and pipes, when you have taken pipe off the top ( intercooler to plenum chamber) check wether the chamber has oil in as well, i hope for you it's just a breather. once cleaned out, see if you can get a 2nd hand turbo and try that, check for play in the rotor (fins) in the turbo, only should have little play in it.
hope this helps
pegleg66