Item Description Genuine breather PCV hose to suit LATE Mercedes Benz M642 this is the 6 cylinder CDI Diesel motor from roughly 2011 onwards

An engine ventilation valve, also known as a PCV (Positive Crankcase Ventilation) valve, plays a crucial role in the functioning of a car's engine. It is a small component that is typically connected to the engine's valve cover or intake manifold.

The main purpose of the engine ventilation valve is to regulate the flow of gases between the engine's crankcase and the intake manifold. It ensures the removal of harmful vapors and gases, such as blow-by gases and unburned fuel, from the engine's crankcase. By preventing the build-up of pressure within the crankcase, the ventilation valve helps maintain a healthy engine performance and prevents potential damage.