Oil from the bearing behind the compressor wheel IS normal. Too much is not! The path from the turbo compressor is to the charge air cooler (aka intercooler) and then to the intake manifold. If there is excessive oil getting past the bearing seal the charge air pipe low spots will fill quickly. Almost always the reason will be too much clearance in that bearing.
It is relatively easy to detect this wear however - remove the intake air pipe where it attaches to the turbo. Reach in with a finger and try to push the shaft radially; up, down and right to left. If you can detect movement it is time to replace that bearing. Practically speaking it means rebuilding the turbo because that is virtually all a turbo rebuild entails.
It is relatively easy to detect this wear however - remove the intake air pipe where it attaches to the turbo. Reach in with a finger and try to push the shaft radially; up, down and right to left. If you can detect movement it is time to replace that bearing. Practically speaking it means rebuilding the turbo because that is virtually all a turbo rebuild entails.