Peugeot 407 diesel crankcase ventilation issue

I've got a 407 diesel too. Those symptoms sound familiar. Had a similar issue a while back. Any rough idling or hissing sounds?

Rough idling sometimes, yes. And now that you mention it, I think I did hear something like a hissing sound recently. Was it definitely the crankcase valve for you?

Yep, that's exactly what it was. Ended up being a defective crankcase ventilation. I'd suggest getting it checked out by a workshop.

Thanks a lot! Shop confirmed it was the crankcase ventilation valve and quoted 360€ for the repair. Appreciate the help!