Recently picked up a 2010 Mini Cooper S (N14) from a friend's dad. He had an issue with it stalling when coming to a stop last year. Took it to a shop and they said it needed spark plugs. He got a call a few days later asking to come in, and he did. The whole front was apart and the turbo was off. They put it back together without doing anything, and now it smokes a lot. Almost immediately after starting. Thicker on idle and clears up a bit as you drive, but still smokes nonetheless. Replaced the valve cover and it no longer stalls, and runs much better. But I'm still getting a lot of smoke. I have lots of oil in the intercooler, which if it was there from the shop I would ASSUME would've burnt off by now. I've checked timing chains and compression, not stretched and reading 160psi across the board. It seems like the turbo is the issue, but I don't want to put one in without being absolutely certain as I can't feel play in it from the air intake side. I also ran the engine with the air intake off, and noticed some oil accumulating by the impeller, but I think it may be coming back through the intercooler. There seems to be a small oil leak by the bottom of the turbo, but could also possibly be from the intake hoses. I'm fine to put a turbo on but I want to be certain that it is my issue. Is there any proper diagnostics for this? I've added photos of the inside of the intercooler, the turbo, and the smoke from the car after running for a few seconds.