Hey guys, I'm from Cluj, Romania and in February this year I bought a 2016 xDrive40e and realized that if the car sits a lot, like more than 2-3 days (due to the pandemic wasn't using it much), at cold starts it was blowing white oil smoke. Researched a bit on that and discovered that the N20 engine has an issue with the oil feed line to the turbo. The fix is to replace that oil line with a revised one that has a built in check valve. When changed the oil feed line the entire turbo has been removed and when fitted back again a kit for turbo replacement parts like gaskets and o-rings was used.
More details about the problem here:
https://bmwtechnician.com/2016/05/13...d-line-update/
The smoke issue is currently fixed, but after getting the car out from the auto-shop and inspecting the engine bay, I was hearing a knocking noise, that I don't recall hearing it before. The guys from the shop inspected all the parts they were touching to be sure everything is put back in place and tried to identify the noise, but they are not sure from where it may come from.
The final conclusion was that is some sort of a valve that's hearing and it's normal.
Another thing to mention is that if I put the car in Sport the noise it's still there but barely noticeable. When putting back in Comfort or EcoPro the sound is back again.
To be honest I don't think it's normal and I'm trying to see if anybody has heard such a knocking in the engine bay that is comparable with what I was recording in this YouTube video:
Any help is appreciated.