oil separator symptoms

[JCL]

While a diesel requires a crankcase ventilation system the same as a petrol engine does, I have no idea if the new BMW diesels are using anything similar in design to the traditional oil separator valve that is discussed above. It doesn't show up in the Realoem parts catalogue, but that may be due to changes in the catalogue as much as changes in design.

I wouldn't spend much time worrying about it, enjoy your new car. If you do a lot of short trips, you may see some accumulated paste under the oil filler cap, and if so that indicates that the engine isn't getting hot enough to burn off the condensation. That is a better thing to check in my opinion than trying to chase down a problem that may not even exist.