My wife's car started making this noise this morning. It's the base model Cooper 161k on the odometer. No engine light or codes are on, running great lots of power. Started up a fairly steep incline when the noise started. Pulled over, let it run long enough to record this video then shut off. Oil level is good as well. Possible timing chain problem??

2009 Mini Cooper Engine Knock - YouTube

UPDATE: turned out to be a minor issue. The serpentine belt was wore out and when the worn out spots hit the tensioner in would move in and out causing that knock sound. I'm embarassed to say I overlooked the belt on this car. Usually I change belts on all my cars around 120K. Since this one is well hidden I never gave it a second thought. Thankfully I had CAA and the dealer was kind enough to squeeze us in and get us back on the road that same afternoon.