Mercedes Engine Crankcase Breather Hose - Vaico 6420101791

Product Information

An engine crankcase breather hose is a primary component of an engine’s positive crankcase ventilation system, funneling pressurized air from the engine crankcase to the air/oil separator, also known as the PCV valve. The PCV valve, or air/oil separator, is designed to capture and remove oil vapors from the pressurized crankcase air, allowing them to drain back to the engine, while the pressurized air is fed to the intake side of the engine and utilized as part of normal combustion.

An engine develops positive crankcase pressure as a byproduct of the overall combustion process. Because of the combination of pressure, heat, and the air/oil-vapor mixture traveling to the PCV valve, the engine crankcase breather hose is a common failure item within the PCV system and is crucial to your car’s engine’s performance and emissions compliance.

• Cracks breaks, leaks: Over time, your engine crankcase breather hose can be easily damaged because of constant exposure to oil vapors, heat, and pressure from the engine. The engine oil can slowly break down the plastic or rubber materials, eventually causing an air leak. This can happen naturally, or because it is damaged from external contact.
• Broken connectors: Plastic can become brittle over time, especially when exposed to heat and oil, and it’s easy to break one of the securing clips or connectors for a PCV hose, either during removal or during other services.
• Broken or damaged hose: Soft rubber or brittle plastic, depending on the material of the hose, can result in an obvious hole or split in an engine crankcase breather hose, usually accompanied by one of the other faults listed below.
• Check Engine Light: Excessive unmetered air from a failed engine crankcase breather hose can result in a CEL for an air intake leak fault or other airflow-related diagnostic trouble codes.
• Misfire: A severe air intake leak can cause rough running and an engine misfire, a common side effect of a bad engine crankcase breather hose or PCV Valve
• Oil residue on or around the hose or adjacent components: As engine crankcase vapors escape from a faulty engine crankcase breather hose, the hose, engine block, and adjacent components are likely to become visibly soiled with oil residue and moisture. In the most severe cases, you will smell burning or burnt oil, and you may need to degrease the area to determine the exact cause of the oil residue.

About Vaico

VAICO premium brand is well known for smart repair solutions for engine and transmission parts on the global independent aftermarket. With over 28,000 high-quality spare parts and 2,700,000 vehicle connections, we guarantee a high level of vehicle coverage: our extensive range of transmission components and spare parts for air control systems and engine control covers a wide range of models. Our professional vehicle repair range also includes further products from the cooling, steering, brakes, body and filter categories, as well as certified “Made in Germany” fluids.

VAICO specializes in providing innovative repair solutions put together by our experts for every workshop: VAICO Expert Kits+ make it easier to identify and procure parts and also reduce the storage capacity needed. The service-orientated Expert Kits+ are easy to install and meet the highest standard of installation safety – and save time and money.