BMW F20 F21 F30 LCI B37 B47 Diesel Air Filter Box Intake Silencer Cover 8578649

BMW F20 F21 F30 LCI B37 B47 Diesel Air Filter Box Intake Silencer Cover is an intake system component designed specifically for BMW F-series diesel engines. Thanks to its factory design, it ensures stable intake air routing, effective intake noise suppression, and proper compatibility with the stock air filter, which translates into smoother engine operation.

Specifications and technical data

• SKU: 8578649-1
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 8578649
• Substitutable numbers: 13718578649, 8578649, KZ
• Weight: 150
• Fuel type: Diesel
• Category: Air Filter Housings

Purpose and function in the intake system

The presented air filter box belongs to the Air filter housings category and is intended for BMW F20, F21, and F30 LCI (facelift) models with B37 and B47 diesel engines. The component performs several key functions in the intake system:

• channels air to the filter and further to the intake manifold,
• stabilizes airflow by reducing turbulence,
• acts as an intake silencer, reducing intake noise,
• protects the filter element from contaminants in the engine bay.

By being tailored to the specific B37/B47 engine generation, the housing supports correct combustion parameters and the maintenance of the engine's factory performance characteristics.

Design and fitment for BMW F20/F21/F30 LCI

The housing was designed by BMW as part of the intake system for diesel engines, ensuring precise fitment with engine bay mounts and other intake components. The design includes:

• integration with the stock air filter and intake ducts,
• built-in intake noise silencer, improving acoustic comfort,
• mounting point placement consistent with factory brackets.

This solution allows for maintaining the original airflow geometry, which is essential for both performance and the durability of diesel engine accessories.

Benefits of using an original air filter housing

Using a factory air filter housing in B37/B47 engines provides measurable operational benefits:

• maintaining stock intake noise levels without unwanted resonance,
• secure sealing of the air filter area against the engine bay,
• compatibility with stock control electronics and intake system sensors,
• easier maintenance when replacing the filter element.

For users who want to preserve the factory character of the BMW diesel engine, the original air filter housing is a safe and predictable solution, minimizing the risk of airflow issues or incorrect sensor readings.

Condition, origin, and practical application

The offered BMW air filter housing comes from the used parts segment, allowing for cost-effective intake system repair while maintaining a component consistent with factory specifications. It is a good solution in situations such as:

• mechanical damage to the existing housing (cracks, broken mounts),
• the need to restore the stock intake after previous modifications,
• repair after a collision in the front section of the vehicle.

Thanks to the original design, installation is predictable, and the housing can be integrated into the existing system without the need for additional modifications.

Expanding the BMW intake system – Air filter housings

If you are planning a comprehensive repair or upgrade of the engine area in your BMW and need other components from the same group, such as additional intake ducts, intake silencer covers, or other filter housings for different engine versions, check out the available parts in the BMW air filter housings category.

For those interested in the broader context of turbocharged engine modifications and the impact of the intake system on performance, an article describing safe power increases in turbocharged engines may be helpful – see the guide on safe power boosting and purchasing used turbochargers, which helps to better understand the relationship between airflow, boost, and accessory durability.