BMW E81 E87 E90 E91 E92 Diesel N47 N57 Intake Silencer Air Filter Box 7811904

The BMW E81 E87 LCI E90 E91 E92 N47 Air Filter Housing Box is an original intake system component designed for BMW diesel engines. It ensures stable mounting of the filter element and proper airflow to the engine, which translates to efficient diesel engine operation and reduced intake air contamination. This is a practical solution for users seeking factory fitment and predictable performance parameters.

Specifications and technical data

• SKU: 7811904
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7811904
• Substitutable numbers: 13717811904, 7811904, 13717797471, 7797471
• Fuel type: Diesel
• Category: Air Filter Housings

Purpose and Function of the BMW Air Filter Housing

The presented housing belongs to the Air Filter Housings category and is structurally adapted for BMW 1 and 3 Series models with the N47 engine. Its purpose is to securely enclose the filter element and direct the airflow so that as clean air as possible, without excessive pressure drops, reaches the intake manifold.

A properly selected air filter box helps to:

• maintain stable operating conditions for the diesel engine,
• limit the ingress of contaminants into the intake system,
• preserve factory airflow parameters,
• minimize the risk of leaks at intake hose connections.

Benefits of Using an Original BMW Housing

An original BMW air filter housing is designed for a specific engine bay architecture, ensuring:

• secure fitment to body mounts and adjacent accessory components,
• compatibility with factory intake hoses and filter elements,
• an appropriately shaped airflow chamber, promoting even engine supply,
• maintenance of the factory intake air noise level.

For the user, this means easier installation, no need for modifications, and predictable vehicle behavior after component replacement.

Characteristics of a Used Part

The air filter housing is offered as a used part, allowing for economical repair of the intake system while maintaining the original BMW construction. Such components are often chosen when the factory box has suffered mechanical damage (cracks, broken mounts, damaged connectors) or when previous repairs involved unsuitable aftermarket replacements.

Choosing a used OEM housing is particularly beneficial when aiming to:

• maintain the original routing of intake hoses,
• avoid problems with fitting universal solutions,
• preserve the structural integrity of the entire intake system.

Compatibility with N47 Diesel Engine

Diesel engines require a stable and well-filtered air supply, as they operate at higher compression ratios and are more sensitive to intake leaks. The air filter housing dedicated to the N47 unit is designed to:

• provide adequate volume of the air chamber before the filter,
• maintain proper operating conditions for sensors in the intake system,
• reduce the impact of air turbulence on the combustion process.

This allows the injection system and engine control unit to operate under conditions close to factory settings, promoting smooth engine operation and stable performance parameters.

BMW Air Filter Housings – Selection and Alternatives

If you are looking for other BMW Air Filter Housings compatible with different models of this brand, check out the BMW air filter housings available in our store to select a component that matches your specific engine and body version.

Those interested in a broader use of the used parts market – including for other brands – can find practical tips on optimizing service costs in the article Volkswagen Repair on a Budget? Discover How to Save on Original Car Parts. You will find information there that helps you make informed choices about used components while maintaining appropriate technical standards.