Engine Vent Oil Separator
WARNING: This page is about a different car, the 2019 Jaguar XE. However, it is still accessible from the selected car via links, so may be relevant.
Piston blow-by gases are drawn through the engine vent oil separator. The gas and vapor are separated. The vapor is drawn into the turbocharger intake duct and added to the air charge.
The depression caused by the engine air intake draws gases from the crankcase, through the engine vent oil separator and the breather hose into the Low Pressure (LP) Exhaust Gas Recirculation (EGR) valve.
The resultant depression in the engine oil pan, front covers and cylinder head covers reduces the load on the joint seals in those areas. Engine oil drawn into the engine vent oil separator is collected on angled plates in the separator. The oil collects on the plates and falls back to the oil pan via a hole in the cylinder block.