Mini Roadster Diesel Engine Issues

Sounds like you might have an issue with the intake manifold airflow control. I had similar symptoms on my Mini Roadster: reduced power, rough running, and even a hissing sound. Have you checked the intake manifold flap control?

That's interesting. How did you diagnose the intake manifold flap control? Did you also get the engine light?

Yes, I had the engine light on as well. A diagnostic scan confirmed the issue. Given your symptoms, it's very likely the intake manifold flap control. I would recommend having it checked at a workshop.

Thanks for the confirmation. I went to my mechanic, and as you suspected, the intake manifold flap control was defective. The repair set me back 465€, but the car is running smoothly again.