i have a small amount of oil in airbox.

sorry i meant the cold air intakes to turbo, oil on top of intake.

If you are talking about the air intake hose to the intake manifold that comes from the turbo, and getting oil onto the intake, the oil is probably leaking from the seals in the turbocharger itself. More then likely need to have turbocharger checked and resealed. If that is what you're asking.

that is what im asking it sounds right, is that a costly problem. thanks

Depends on your thought of costly. Use the Estimator on top of this page for a price in your zip code area, I'm in Texas.