2021-2024 BMW 4 Series Gran Coupe / X4 Trunk Groaning Noise

Owners of 2021-2024 BMW 4 Series Gran Coupe and X4 models may experience a distinct groaning noise originating from the trunk lid. This issue, specifically described as "A groaning noise is heard from the trunk when driving on rough roads," can be a source of annoyance and is addressed by BMW Technical Service Bulletin (TSB) SIB 51 18 23, issued on September 25, 2023.

Symptoms

The primary symptom is a noticeable groaning noise that comes from the trunk area. This sound is particularly prevalent and easily heard when the vehicle is traveling over uneven or rough road surfaces. The TSB highlights the exact owner-facing symptom: "A groaning noise is heard from the trunk when driving on rough roads."

Cause

BMW has identified the root cause of this groaning noise. It stems from an unfavorable gap tolerance between the wedging element located on the trunk lid and the corresponding stop pad situated on the vehicle body. This slight misalignment or excessive gap allows for movement and friction, leading to the audible groaning sound.

Repair Procedure Summary

BMW TSB SIB 51 18 23 outlines two distinct correction procedures, which depend on the vehicle's production date. This repair is also noted as being "MOBILE FRIENDLY," suggesting it can be performed with relative ease.

Correction 1: For Vehicles Produced Up to January 20, 2023

For vehicles manufactured on or before January 20, 2023, the repair involves a cleaning and lubrication process. Technicians are instructed to clean the trunk lid's wedging element using a mixture of denatured alcohol and water, applied with a clean rag. Following the cleaning, Berucoat AK 978 anti-squeak paint is applied to the wedging element. The trunk lid must then remain open for eight minutes to allow the Berucoat AK 978 to dry completely.

Correction 2: For Vehicles Produced After January 21, 2023

For vehicles produced after January 21, 2023, the repair procedure is different. Instead of cleaning and lubrication, the trunk lid requires adjustment. Technicians must follow specific repair instructions detailed in the ISTA/AIR system, under reference 41 62 014, to correctly adjust the trunk lid and eliminate the unfavorable gap tolerance.

Required Tools or Parts

For vehicles requiring Correction 1, the specific anti-squeak paint is necessary:

• Part Number: 83 19 2 358 109
• Description: Anti squeak paint Berucoat AK 978 (100ml)

Claim Information and Warranty Coverage

This repair is covered under the terms of the BMW New Vehicle Limited Warranty for Passenger Cars and Light Trucks. Dealers will use Repair Code 5124403900, labeled as "Tailgate wedging element Unpleasant noises," when submitting claims. Specific labor operations are provided for diagnosis and correction, such as 51 00 001 for localizing body complaints or 51 99 000 for cleaning and lubricating the wedging element, depending on the production date and specific repair performed.

Important Notes for Owners

BMW has provided an internal video reference, V51 09 23, to assist technicians with diagnosing and performing this repair. Owners should be aware that this issue is a known concern addressed by BMW, and the necessary repairs are covered under warranty.

Source: NHTSA ID: 10242880