BMW Hex Bolt (2002 318i 320i) - Genuine BMW 11120621144

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 BMW

The original parts used by BMW to build your car are available as replacement parts under the “Genuine BMW” brand. When ordering a Genuine BMW part you are guaranteed to get the same part that you would pick up from your local dealerships part department. Genuine BMW parts have been built to BMW’s stringent standards and are the same quality of the original parts used to build your Ultimate Driving Machine.

You may not realize this, but the parts that make up your BMW are not necessarily manufactured by BMW. No cause for concern, as BMW designs the part, hires a manufacturer, and ensures its quality to you. In fact, many of these manufacturers have been making parts for BMW 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 BMW parts box and find an OEM branded part inside, simply with the addition of a BMW 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.