BMW Engine Cylinder Head - Genuine BMW 11121748391

Product Information

BMW Cylinder Head and Components diagram for 325is, 525i, 325i

An Engine Cylinder Head is a major engine component that sits on top of the engine block, sealing the combustion chambers with the help of a head gasket. It houses critical parts like the intake and exhaust valves, spark plugs (in gasoline engines), fuel injectors (in some designs), and sometimes the camshafts.

Functions

• Seals the combustion chamber: Works with the head gasket to maintain compression and contain combustion gases.
• Airflow management: Controls intake of the air-fuel mixture and exhaust of burnt gases through valves.
• Houses components: Provides mounting for valves, valve springs, rocker arms, injectors, and spark plugs.
• Cooling & lubrication: Contains passages for coolant and oil to regulate temperature and lubricate moving parts.

• Overheating engine – coolant leaks or blocked passages cause heat buildup.
• Loss of power / misfires – due to poor sealing or damaged valves.
• White smoke from exhaust – coolant leaking into the combustion chamber.
• Oil contamination ("milky oil") – coolant mixing with engine oil inside the head.
• Coolant loss with no visible leak – internal leakage through cracks or warpage.

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.