PCV / CCV Valve 
For
BMW N55 Engine
 
As found in the BMW M135i, M235i, M335i, and M435i
Aswell as many other models
 
This part is a common failure on these engines, Failure symptoms include: a rough idle, burning oil,
Heavy breathing / smoke from engine bay, Engine Management Light - "Lean Mixture", Reduced Performance / economy.
 
This part is bonded to the valve cover, so the old one requires carefully cutting off, and the new one bonding on.