Hello and welcome! I'm Billy and i will assist you with this.
My apologies for the delay, thank you for your patience.
I do understand your frustration, as this is costing too much money, time and effort, and the problems seem to never end.
However, even if they overfilled with oil, the turbo seals should not get affected.
Having the oi leak before, might have been the cause to slowly deteriorate the turbo, as oil was getting low in the engine.
And having the whooshing noise as you describe it, does indicate a turbo problem.
However, after that is fixed, and if you have any other problems, and before replacing injectors, you need to have them to check and clean the fuel flow control valve. As this is a common issue on your engine, causing performance problems:
click here for details
Kindly get back to me with your results, or if further assistance is needed.
Thank you for your trust! Get back to me if you need more assistance...Thank you in advance for the positive rating...http://www.justanswer.com/car/expert-billy/