Originally Posted by powers1

Yes..The swirl flap issue is caused by the EGR exhaust fumes+inlet oil vapours accumulating and creating a paste that hits and blocks up the flaps.In the worst cases I have seen,the flaps get swallowed by the engine.

In the E53 3.0D ,as its vacuum operated,its a simple fix!Just block off the vacuum pipe that opens egr channel from exhaust.No error lights and no more gunk going into the engine.Egr opens up mainly around short town trips and remains closed on highway trips or WOT,so you get more "gunk" into your engine if you just drive mainly around town.
On later 3.0D ,if you disconnect the egr system ,it will bring your EML on,so only way if disconnect the egr is to have the EGR map on the cars software disabled.