[Tcoat]

Oil starvation issues on post 13 models are very, very rarely reported on here. I think I remember reading about maybe 3 others in total.
It may be a bit of a fight especially since it is a used car. Who knows what the previous owner put it through. The dealer should pull the engine apart and look for passages blocked by sealant but they may want to charge for that. They should also check the oil pump as there is at least one recorded case of it failing. My bet is you will find that the #4 crank bearing has spun. If they won't cooperate then it may pay to take it to another shop and have them check. Of course if they find nothing then there would be no case but if they do it may be the proof that would sway a warranty claim. Overall expect a fight though.