BMW G20 G21 G30 G31 G11 G12 Diesel B57 330d Oil Filler Neck Cap 7810585

BMW G20 G30 G31 G11 G12 Diesel B57 330d Oil Filler Neck Cap is an original lubrication system component designed for BMW B57 diesel engines. This used part, from the Oil Drain and Filler Plugs & Dipsticks category, ensures proper closure of the oil filler, stabilizing engine operation and reducing the risk of leaks. It's a practical solution for users who want to maintain the original engine design and proper service conditions.

Specifications and technical data

• SKU: 8579601
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 8579601
• Substitutable numbers: 8579601, 11128579601
• Fuel type: Diesel
• Category: Oil Drain Plugs, Filler Caps & Dipsticks

Purpose and Function in B57 Diesel Engines

The oil filler neck with cap in a diesel engine is responsible for safe lubricant replenishment and sealing the system. In B57 units, fitted in models from the 3, 5, and 7 Series, among others, this component works with the valve cover and oil channels, contributing to:

• maintaining adequate pressure in the engine compartment,
• protection against contaminants entering the oil,
• stable oil service (changes and top-ups),
• compliance with the original engine accessory geometry.

By retaining its original design, the neck with cap works in conjunction with factory seals and the ventilation system, promoting smooth engine operation.

Benefits of Using an Original BMW Oil Filler Cap Neck

Using an original part to replace a worn or damaged one helps maintain the integrity of the entire lubrication system. In practice, this means:

• precise fit to the engine cover – no need for modifications or adapting aftermarket alternatives,
• maintaining factory-level sealing at the oil filler area,
• reducing the risk of leaks and engine bay contamination,
• preserving proper operating conditions for the oil in the diesel unit.

For drivers who use their car intensively, especially in models with more powerful engine variants, a properly functioning oil filler cap is an important element of preventative maintenance.

Assembly and Operational Characteristics

The component is designed as a genuine BMW part, facilitating installation in the location intended by the manufacturer. In practice, this means:

• compatibility with diesel engine lubrication systems,
• maintaining the correct position of the neck relative to engine accessories,
• the ability to repeatedly unscrew and screw the cap during oil service.

A used part allows for economical repair while maintaining original specifications, which is particularly important for modern diesel engines sensitive to lubrication quality.

Practical Service Application

Replacing the oil filler neck with cap is recommended when there are signs of leaks, mechanical damage, or issues with the cap sealing properly. A correctly chosen part helps to:

• maintain cleanliness in the engine compartment,
• minimize oil evaporation and leaks,
• preserve stable engine operating conditions over the long term.

For owners of diesel cars, choosing an original oil filler cap neck is a way to maintain the structural consistency of the entire lubrication system.

If you are planning a comprehensive repair or upgrade of the engine area in your BMW and need other parts from the same group, such as oil drain plugs, additional filler caps, or dipsticks, check the available parts in the BMW Oil Drain and Filler Plugs & Dipsticks category.

To better plan your service maintenance and understand how individual components affect engine longevity, it's worth referring to the practical advice in the article TOP 10 Most Frequently Replaced Parts in Your Car.

Additionally, for a more comprehensive view of the impact of operating temperature and lubrication on engine lifespan, the guide Engine Cooling System – Overheating, Repair, and Used Radiators, which discusses the relationship between the cooling system and engine condition, may be helpful.