MMX Performance BMW S55 / N55 / N54 Oil Thermostat Housing Cover Kit

The MMX Performance BMW Oil Thermostat Housing Cover Kit for N54, N55, and S55 engines is a premium upgrade designed to replace the factory plastic components with a durable billet aluminum solution. While the OEM thermostat cover is prone to cracking and degradation over time, the MMX kit delivers improved reliability along with a refined OEM+ appearance.

Each cover is precision machined from T6061 billet aluminum, offering significantly greater strength and resistance to heat-related wear compared to the factory plastic design. This eliminates a common failure point found in aging BMW engines, helping to prevent leaks and maintain long-term performance.

Finished in MMX’s signature deep gloss black anodized coating, the thermostat cover enhances the visual appeal of the engine bay while providing corrosion resistance and durability. The clean, machined finish integrates seamlessly with other MMX billet engine components for a cohesive under-hood upgrade.

For enthusiasts looking to monitor engine performance more closely, the kit is available with an optional 1/8NPT threaded port. This allows for the installation of an oil pressure sensor or oil temperature gauge, making it an ideal solution for both street and track-focused builds.

Installation is straightforward, making this an easy yet impactful upgrade for improving both reliability and aesthetics in one step.

Product Details

• Precision machined from T6061 billet aluminum
• Replaces failure-prone OEM plastic thermostat cover
• Improves durability and prevents cracking or leaks over time
• Deep gloss black anodized finish for corrosion resistance
• Optional 1/8NPT port for oil pressure or temperature sensors
• Enhances engine bay appearance with OEM+ styling
• Simple, direct-fit installation
• SKU: MMR03-0502-BL

Notes

• Fits BMW N54, N55, and S55 engine applications
• If installing an oil pressure sensor or temperature gauge, select the optional 1/8NPT threaded version
• Prolonged exposure to extreme heat may affect anodized finish over time
• Includes a 1-year manufacturer warranty against defects in materials and workmanship
• Designed and tested in the United Kingdom