Audi VW Cylinder Head Bolt (A8 Quattro) - Genuine VW Audi 07D103385A

Product Information

An engine cylinder head bolt is a critical fastener that holds the cylinder head firmly onto the engine block. This secure fit ensures a tight seal between the cylinder head and the engine block, allowing for efficient compression and combustion, and preventing oil or coolant from leaking into the combustion chambers. Cylinder head bolts are designed to withstand extreme pressure and high temperatures generated during engine operation and are often torque to yield fasteners, meaning once removed they are meant to be replaced.

• Coolant or Oil Leaks: A failing or loose cylinder head bolt may cause the head gasket to lose its seal, allowing coolant or oil to leak externally or into the combustion chamber
• Engine Overheating: A poor seal between the head and the engine block due to a failing head bolt can lead to coolant leaks, reducing the coolant level and causing the engine to overheat. This may trigger a temperature warning on the dashboard
• Reduced Engine Performance: A compromised head bolt may allow air or gases to escape the combustion chamber, leading to reduced compression and performance

About Genuine VW Audi

The Volkswagen Group, also known as “VAG”, consists of Volkswagen, Audi, Lamborghini, Bentley, Bugatti, Porsche, Ducati, MAN, Scania, SEAT, and Skoda. The original parts used by VAG to build your car are available as replacement parts under the “Genuine VAG” brand. Manufactured under the direction of VAG, expect excellent quality and a premium price since these parts are available exclusively through the VAG Dealership network.

You may not realize this, but the parts that make up your VAG are not necessarily manufactured by VAG. No cause for concern, as VAG designs the part, hires a manufacturer, and ensures its quality to you. In fact, many of these manufacturers have been making parts for VAG for decades. In our industry these manufacturers are called OEM (Original Equipment Manufacturers), and these are often brands you recognize, including Lemforder, ZF, Sachs, Bosch, Valeo, Zimmermann, Siemens VDO, Corteco, and more. Don’t be surprised to open that Genuine VAG parts box and find an OEM branded part inside, simply with the addition of a VAG logo.

Be sure to keep an eye out for OE tags on our product pages to quickly identify parts coming direct from OE manufacturers. That extra bit of insight could save you some serious money while shopping! Refer to our OE Academy for further information regarding the OE/OEM tags throughout the site.