Problem with oil leaks at turbo seals on our 2012 Mercedes E-350 BlueTec Diesel. I that common?
As you can tell by the lack of replies, not many people here (if any) have experience with your problem. Have you posted this on a MB forum?
Seals on a turbo start to leak from lack of maintenance, (oil changes), or the oil drain-back is restricted forcing oil past the seals.