In starting this thread 2 years ago I was trying to determine limp mode and excessive oil consumption. As mentioned in last post the limp mode was solved. However, almost 2 years later and only 4k miles put on the car, the oil consumption was solved. We only used the car locally as a backup to minimize the oil usage. But, during this time I continued the investigation. This spring I found a Youtube video titled Sprinter Turbo replacement. It's well done by a true mechanic. He pointed out the reason for the change. With engine running, you could see a stream of oil coming out of the turbo. So, I removed the intake tube from the turbo and didn't even need to start it. There was a black oil residue line in exactly the same place as the video! Installed a new Garrett billet turbo and went through the whole system cleaning and resealing a o rings. since completion, the car has been driven a freeway speeds for 200 miles with no oil loss. NOTE: there was no wobble in the turbo shaft it was a failed seal. I always hate when a thread gets started and there is never a solution given. Hope this helps others!