Yes, but according to assorted MB service documentation & TSB's, oil in the intake manifold is normal and not a cause for warranty repair (which to me means OOW repair too). If you have zero blue smoke and oil consumption is relatively low, it's usually not an issue.
If it really bothers you and need to find out, you can route the PCV pipe to a plastic containter or small K&N fitler something, and plug the intake hole. Remove & clean the charge pipe completely. Drive the car for a few hundred miles, then pull the pipe & look inside. If there's oil, it has to be from the turbo. If not, it was from the PCV inlet.
