These diesels have their downsides, but honestly, I will take it anyday over the N62 and N63. N52 and N55 seems to fare much better.
My diesel has faulty DEF transfer pump, but instead of spending $400 i just keep adding DEF to the active tank every 2-3 k miles.
I visited a shop yesterday that are fixing '12 X5D with a broken active tank. I have to take a better look at it and take some pictures.