Mini Cabrio Diesel Engine Power Loss and Whistling Noise

Whoa, sounds like a real headache! I had a similar issue with my old Peugeot – a totally different beast, I know – but the symptoms were eerily similar. Check engine light, limp mode, the whole shebang. Turned out to be the turbo actuator. Was there any weird noise? When the turbocharger kicks in, can you hear a loud hissing when accelerating?

Interesting. You mentioned a turbo actuator issue with your Peugeot. Did you also experience any whistling noises or stalling at idle? And did you manage to fix it yourself, or did you end up taking it to a shop?

Yep, whistling and hissing were definitely part of the symphony of horrors! Stalling wasn't a major issue for me, but the inconsistent idle was noticeable. I tried a few things myself, but honestly, messing with the turbo actuator valve without the right tools and knowledge can be risky. I'd recommend getting it checked out by a mechanic. They can properly diagnose the issue and replace the boost control valve if needed. Might save you a bigger headache down the road. Good luck!

Just wanted to give you an update. It was indeed the boost pressure actuator valve. Got it replaced, and the Mini is back to its old self. The whistling is gone, power is restored, and no more check engine light. Cost me around 250€, which is what I expected. Thanks again for your help!