Genuine OEM BMW Crankcase Ventilation Hose, part number 11157567802. This hose plays a vital role in the crankcase ventilation system by routing harmful gases from the crankcase back to the intake manifold for re-combustion. This process helps to reduce emissions and prevent pressure buildup within the engine. The hose features a flexible, heat-resistant construction. Genuine OEM parts ensure the correct diameter, material composition, and connection points for a secure and effective seal, maintaining engine efficiency and emissions compliance.