2001 BMW 330 xi, oder inside car while idling, not continuous.

There might be a wire or hose that is contacting a hot surface. You might not see a leak or notice a change in the oil level that seems like it is burning oil, but if you smell it it more than likely is doing it somewhere. It could also be power steering or tranny fluid leaking and getting on the exhasut. Also, check the PCV valve and make sure that it moves around when you shake it. If it does not you can clean it with some brake cleaner by spraying it out and wiping it with a rag or paper towel. Spray it from the bottom entrance that would be towards the engine and not from the side that connects it to a vacuum hose. Spray it out until you can hear the internal one way piece move back and forth when you shake it. The other option is to buy a new one. If it is not working it might be burning some gases that smell or the EVAP or EGR might be dirty as well and need to be sprayed out and cleaned in the same manner.