Hello guys from Europe.
I bought 2nd hand 2012 Mini r60 Cooper S Countryman ALL4 With 108 000km (70ish thousend miles in your weird units)
It is fully Loaded and very fun to drive, but pain in the #ss to maintain as you already know.
I got really weird noise so its best for you to watch video I just uploaded,
Car is maintained in Official Mini BMW dealership with full history and loads of repair bills.
As soon as I got the car this noise appeared sometimes, not always and mostly when its not Cold outside.
Car had issues with Vanos and hopefully I fixed them, but this Noise is still haunting me.
No more Engine codes, or any other codes that can suggest me what is wrong with the car
I was happy to see that HPFP is almost brand new in the car, but now I'm suspicious that it already failed.

Here is the videos Link

 

When cold, mine seems like it holds the wastegate open for a little bit which makes more noise. Yours sounds like a hose is loose or cracked. After a little bit it closes and the car quiets right own.

 

Thank you. Gonna check wastegate when weather gets better