Audi S5 8T Vent Pipe Cylinder Head Breather Line Hose 4.2 FSI 079103217S

Audi S5 8T Cylinder Head Vent Hose 4.2 FSI is an original part from the hoses, pipes, and tubes group, designed for the ventilation system of the 4.2 FSI unit in the Audi S5 8T model. It ensures proper gas discharge from the cylinder head, promoting stable engine operation and reducing the risk of crankcase ventilation system leaks.

Specifications and technical data

• SKU: 079103217S
• Mark: Audi
• Condition: Used
• OEM Part Number: 079103217S
• Substitutable numbers: 079103217S, 079 103 217 S
• Part type: Hose
• Category: Hoses, Lines & Pipes

Purpose and Function of the Hose

The cylinder head vent hose in the 4.2 FSI engine is responsible for the controlled discharge of gases from the cylinder head chamber to the intake system or crankcase ventilation. A properly selected component:

• stabilizes pressure within the cylinder head,
• reduces blow-by and unwanted oil leaks,
• supports smooth operation of the powertrain under various loads.

By using an original hose dedicated to the Audi S5 8T with the 4.2 FSI engine, compliance with the factory ventilation system design is maintained.

Construction and Fit for Audi S5 8T 4.2 FSI

The offered element belongs to the Hoses, pipes, and tubes category, meaning it is designed to operate in high-temperature environments and in contact with oil and fuel vapors. The shape of the hose, connection diameters, and port layout are adapted to the geometry of the cylinder head and the accessories of the 4.2 FSI engine in the Audi S5 8T.

Original origin from the Audi brand promotes:

• secure fit with factory mountings and clamps,
• maintenance of proper ventilation system flow,
• minimization of collision risk with other engine compartment components.

Characteristics of a Used Part

The hose is offered as a used part, allowing for economical repair of the ventilation system while maintaining original Audi specifications. Such components, sourced from disassembly, are often chosen in situations where the existing hose has:

• cracked due to material aging,
• become leaky at the connections,
• suffered thermal deformation causing leaks.

Using an original used hose is often more advantageous than installing an aftermarket replacement with uncertain material specifications, especially in the thermally demanding 4.2 FSI engine.

Benefits of Using an Original Vent Hose

Replacing a worn cylinder head vent hose with an original Audi part translates into several significant operational benefits:

• More Stable Engine Operation – proper ventilation reduces pressure fluctuations and improves the smoothness of the unit's operation.
• Reduced Oil Leaks – a sealed hose minimizes the risk of oil contamination around the cylinder head and intake.
• Preservation of Factory Configuration – no need for modifications, diameter adjustments, or additional connectors.
• Better Diagnostics – a ventilation system compliant with the original facilitates subsequent assessment of potential faults.

Selection and Other Audi Hoses, Pipes, and Tubes

When selecting a vent hose for the Audi S5 8T 4.2 FSI, it is crucial to compare its shape, diameters, and routing with the currently installed component. If in doubt, it is advisable to compare the hose with the service documentation or engine bay photos of the specific S5 variant.

If you are also looking for other Audi Hoses, pipes, and tubes, check out our dedicated category: Audi hoses, pipes, and tubes. This will allow you to easily assemble other components for the ventilation, cooling, or fuel systems suitable for your model.

For drivers interested in safely purchasing used parts, especially for critical systems, we also recommend the guide: how to safely select used brake system components – discs, calipers, and ABS. Although it concerns brakes, the principles of part condition verification presented there can largely be applied to other vehicle components as well.