Big learning experience this week - Oil add warning came on (7000 on a quart is okay with me) so I proceeded to add a quart. 10 miles later the idle becomes extremely rough and the transmission is not downshifting correctly when coming to a stop.
Pull out the scanner and it shows MAF malfunction, Cylinder Bank 1 lean, and Fast Idle inconsistent. Thanks to prior MAF experience, I go ahead and order the genuine BMW replacement from FCP. Takes 2 extra days just to ship out.
In the meantime, big puddle of oil under the engine the second night after the MAF error. All I could think of was the dealership had "amplified" the oil pan gasket seepage activity when they replaced my water pump, but it's dark and too late to check further. Next day there's another puddle at my space at work. I open the hood to examine and find oil sprayed all over the passenger side of the engine because



I didn't get the oil filler cap back on all the way.
Once secure, I reset the codes and everything is good again. Never saw an engine go so bonkers with a loose oil filler cap. I was also relieved there wasn't any shady activity from the dealership involved.