BMW 3 Series E90 E91 LCI Seal Outer Left Mirror Triangle N/S 7139347

BMW E90 Gasket Foam Triangle Mirror Left is a precisely fitted component from the Doors and Door Panels group, responsible for the sealing and stable mounting of the left mirror on the front door. Thanks to the use of foam with an appropriate profile, the gasket limits the ingress of moisture, noise, and contaminants into the door interior, improving the comfort of using the car.

Specifications and technical data

• SKU: 7139347
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7139347
• Substitutable numbers: 51337139347, 7139347
• Location on the vehicle: Left
• Category: Doors & Door Skins

Purpose and Function of the Mirror Gasket

The triangular foam gasket mounted at the base of the left mirror in the BMW E90 series is responsible for properly sealing the contact between the mirror and the door panel. This element:

• creates a barrier against water and moisture in the mirror mounting area,
• helps reduce air noise around the pillar and door,
• supports the stable mounting of the mirror assembly relative to the door panel,
• protects paint edges from direct contact with the mirror component.

Therefore, replacing a worn or deformed gasket with a functional one allows for the restoration of proper mirror operation and maintains adequate sealing in the door area.

Fitment for BMW and Vehicle Placement

The presented gasket has been specifically designed for the door construction of BMW E90 models, ensuring a precise fit to the shape of the mirror's triangular mount. The component is intended for installation on the left side, as indicated by the vehicle placement marking, which eliminates issues with universality and the need for modifications.

This solution facilitates installation in factory mounting points, ensures proper adhesion of the foam to the door panel and the mirror base, and helps avoid stresses that could lead to leaks or unwanted vibrations.

Characteristics of a Used Part

The foam gasket is a consumable part that operates in varying temperature and humidity conditions during vehicle use. A used version allows for economical replacement while maintaining original geometry and compatibility with factory mounting. This solution is particularly beneficial for post-accident repairs, mirror replacement, or restoring sealing after door panel removal.

Choosing an original used part reduces the risk of fitment issues that can occur with aftermarket alternatives featuring a different foam profile or inaccurately reproduced triangular mounting shape.

Benefits of Proper Gasket Replacement

Replacing a worn mirror foam gasket with a functional part offers a range of practical benefits for the daily operation of a BMW E90:

• reduced water ingress into the door interior in the mirror mounting area,
• limitation of potential cracks and resonances around the mirror triangle,
• more stable mounting of the mirror assembly relative to the door panel,
• better protection of paint edges against mechanical damage.

For the user, this means more predictable mirror behavior while driving and maintaining proper operational quality of the doors and body components.

If you are planning a comprehensive repair or upgrade of the door area in your BMW and need other parts from the same group, such as panels, reinforcements, or additional seals, check the available parts in the BMW Doors and Door Panels category.

Support for Choosing Used Parts

When selecting parts from the secondary market, such as gaskets, mirrors, or body components, it is worth paying attention to the source of origin, compatibility with the specific body version, and the actual condition of use. Additional tips on comparing new and used parts, their cost-effectiveness, and durability can be found in the article Car Parts – New or Used? Comparing Costs, Quality, and Durability, which will help you plan your car repair consciously.