I have had this exhaust leak noise only when the engine was cold and could be heard when having to accelerate into traffic. I went and investigated this on the weekend.

Yes a cracked manifold in two places either side of the turbo inlet. You need a mirror and a good torch to see it. The manifold is not cast iron rather it looks like S/Steel to me. The tell tale is exhaust soot on the waste gate can/diaphragm and also on the inner mud guard or strut tower on my car.

I am speaking with Cliff at partsagent.com.au about this part now.

I also have an oil leak dripping from under the compressor housing which I need to get tot the bottom of. PCV valve was changed 15K ago so I am hoping it isn’t the turbo seals, rather it is oil vapour getting past the PCV valve and leaking from the hoses externally on it way to the turbo inlet.

Starting to question why came back to BMWs after so many years or reliability with Subaru and Mazda.

Cheers, Dan.