Putting alot of black smoke out

Carbon build up in the manifold. Now turbo and diesel pump new. Now lots of white smoke and oil coming from exhaust. since my diesel vito had alot of black smoke coming from exhaust i took to mechanic, he found in the manifold had alot of carbon deposits . He replaced the turbo and pump. Now i have oil in the exhaust system and lots white smoke coming from exhaust. The car runs but lots of smoke