Fluence intake manifold flap issue

Sounds familiar! I had almost the exact same symptoms with my old Opel Insignia. Reduced power, rough running, and that hissing noise drove me nuts! In my case, it was also related to the air intake and airflow control. Have you checked for any error codes? That might give you a more precise indication.

Thanks for the quick reply! Yes, I did check for error codes, and it pointed towards a fault with the intake manifold flap control. I'm trying to gauge how serious this is and whether it's something I could potentially tackle myself or if it's best left to a workshop. What was the final diagnosis and repair for your Insignia?

Okay, error code pointing to the manifold flap control pretty much confirms it. Honestly, based on my experience and what you're describing, I'd say it's best to take it to a workshop. On my Insignia, the flap itself was jammed, and the control motor was shot. It required replacing the whole intake manifold assembly which was a bit too complex for me to do at home. Better safe than sorry, you don't want to risk further damage!

Thanks, that's really helpful! I appreciate you sharing your experience. I've booked it in with a local mechanic. They've confirmed it's a defective switch for the intake manifold control, repair will be around 465€. Hopefully, that will solve the issue!