Citroen C5 boost pressure issue

Sounds familiar. I had a similar experience with my C5. The symptoms you're describing – reduced power, weird noises – definitely point to a boost issue. Have you checked the pressure sensor or given the throttle body a good look? Might be worth a quick check before diving into the deeper end.

Thanks for the quick reply! I haven't specifically checked the pressure sensor. Where is it located? And when you say 'good look' at the throttle body, what exactly are you suggesting I look for?

The pressure sensor is usually mounted on the intake manifold, or close to the turbocharger. Regarding the throttle body, check for carbon buildup or any obstructions. If it is gunked up, it could be messing with the airflow and boost pressure. In the end, I had to take it to the workshop. Wastegate valve needed replacement.

Thanks a bunch for confirming my fears, even though it's not the news I wanted to hear! I took your advice and brought it to the workshop. Turns out, you were spot on – the wastegate valve was indeed faulty. Cost me 860€ to get it sorted. Appreciate the help!