Sounds like you have a leak around the intake manifold or maybe the air bypass valve is stuck. On some turbo types there's a hard plastic tube going from the turbo air to some black plastic device under the intake manifold. That often splits at the end. I know it sounds kind of strange but I've seen my son hunt for leaks by duct taping the family vacuum cleaner to the exhaust pipe and then getting some insense going. The smoke gets sucked into any exhaust pipe or intake manifold leaks. Doesn't smell too bad either.