Berlingo rough running intake manifold flap

Sounds familiar! I had almost the exact same symptoms in my old Vauxhall Astra: reduced power, rough idle, the whole shebang. The intake manifold flap, or swirl flaps, are designed to optimize airflow. When they stick or the control mechanism fails, it can cause problems. When you say flap control, are you thinking the actual electric switch?

Exactly that! Is it possible to check somehow? I am not sure if it's electrical or mechanical. Which part was defect on your car?

On my Astra, it was the actuator motor for the swirl flaps that had gone bad. It's a common problem, apparently. Best way to diagnose it would be to get it hooked up to a diagnostic tool to read the fault codes. If it is the intake manifold flap control, or switch, as you mentioned, then yeah, it'll likely need replacing. I'd recommend taking it to a workshop to get it checked out.

Thanks a lot for the advice! I took it to the workshop today, and they confirmed it was indeed the intake manifold flap control. They're quoting me 465€ for the repair. Ouch! But at least I know what the problem is now. Thanks again!