Crankcase Breather Hose – Audi 4.2L V8 (B6 / B7 S4 & C5 Allroad)

Part Number: AUT-B6-003
OEM Reference: 079 103 221 C

Replace your cracked or failing factory crankcase breather hose with this high-quality performance silicone upgrade, designed specifically for Audi 4.2L V8 applications. Built to withstand heat, oil vapor, and long-term engine bay stress, this hose helps restore proper crankcase ventilation and maintain consistent engine performance.

A deteriorated breather hose can lead to vacuum leaks, rough idle, oil contamination issues, and reduced engine efficiency. This upgraded silicone replacement ensures a tighter, more durable seal compared to aging OEM rubber components.

Features

• Direct replacement for OEM part number 079 103 221 C
• Heavy-duty performance silicone construction
• Designed for high-heat crankcase ventilation applications
• Resistant to oil vapor, heat cycling, and cracking
• Restores proper crankcase breathing and vacuum stability
• Improves idle quality and long-term engine reliability
• Ideal OEM replacement or preventative maintenance upgrade

Fitment

Compatible with Audi 4.2L V8 applications, including:

• 2004–2005 Audi S4 B6 4.2L V8
• 2005–2008 Audi S4 B7 4.2L V8
• 2001–2005 Audi Allroad C5 4.2L V8

⚠️ Always confirm OEM part number fitment before ordering.

Installation Notes

• Direct replacement in OEM routing
• Minor trimming may be required depending on vehicle condition or intake modifications
• Professional installation recommended for best sealing and fitment

What's Included

• (1) Silicone Crankcase Breather Hose

Brand Information – Autobahn Autoworx

Autobahn Autoworx hose kits are engineered for long-term durability and performance. All coolant hoses feature 3-ply construction, while boost, breather, ISV, and intake/inlet hoses utilize reinforced 4-ply silicone for maximum strength and reliability in high-performance and daily-driven applications.