2021 Audi A6 Creaking Noise During Braking or Steering

Symptoms

Owners of affected 2021 Audi A6, A7, S6, S7, RS 6 Avant, and RS 7 models may experience a distinct creaking noise emanating from the floor area. This 2021 Audi A6 creaking noise is particularly noticeable during specific driving conditions. The noise typically occurs when the vehicle body twists, such as during strong braking or steering maneuvers. Technicians have identified the source of this noise as radiating from the footwell area to the area under the seat.

Technical Background

Audi has determined that the 2021 Audi A6 creaking noise is caused by the longitudinal members making contact with their internal support plates. This contact occurs during cornering or hard braking maneuvers, which induce body twist. The manufacturer has implemented an improved construction for the longitudinal member assembly in newer production vehicles to prevent this issue.

Diagnosis and Trigger Conditions

To accurately diagnose the 2021 Audi A6 creaking noise and confirm that TSB 2061672/2 is the appropriate solution, a specific diagnostic procedure is followed:

1. Test Drive: A test drive, ideally with the customer, is performed to duplicate the noise under the conditions it typically occurs. This helps confirm the noise originates from the longitudinal member.
2. Subframe Bolt Loosening: The front-most bolt on the subframe mounting is loosened several turns but not removed. This step can sometimes elicit a 'cracking' noise, further confirming the issue.
3. Temperature-Dependent Noise: If the noise is difficult to reproduce when the vehicle is cold, the area of the body near the rear transverse link is warmed to approximately 65°C (149°F) using a hot air blower set to an outlet temperature of about 550°C (1022°F). The surface is then allowed to cool to approximately 30°C (86°F) before another test drive. Lowering the vehicle from a hoist after warming can also immediately trigger the noise.

If these diagnostic steps do not change or eliminate the noise, the repair described in this TSB will not be effective, and further diagnosis outside the scope of this procedure is required.

Repair Procedure Summary

The repair outlined in TSB 2061672/2 involves modifying the longitudinal member to prevent contact with the internal support plates. The key steps are:

1. Access and Foam Removal: The center cover plate on the affected side is lowered, and the first body plug aft of the bolted connection for the transverse link is removed. Sections of acoustic foam within the longitudinal member area are removed using long needle-nosed pliers to provide access.
2. Tool Fabrication: An improvised tool is fabricated from an 8mm diameter, 60 cm long steel rod. One end of the rod is ground into a chisel shape, with the grind length being 15mm +/-3mm on each side.
3. Longitudinal Member Modification: The chisel end of the steel rod is inserted into the body opening, through the remaining acoustic foam, until it engages the longitudinal member support. The steel rod is then driven 4-5 cm into the longitudinal member support using a hammer, effectively modifying the contact area.
4. Final Test Drive: After the repair, a final test drive is conducted to ensure the noise has been eliminated to the customer's satisfaction.

Required Parts and Tools

Technicians will need to consult ETKA for specific fasteners, bolts, nuts, and screws required for the repair. Additionally, the following specific parts are mentioned:

• 8K0805267: Drain tube grommet (Quantity: 02)
• N 91247202: Bolt hex head (Quantity: 02)

An improvised steel rod, 8mm in diameter and 60 cm long, with a chisel-ground tip, is also required for the modification process.

Warranty Information

This repair, identified by Service Number 5079 and Damage Code 0010, is covered under Audi's warranty for up to 48 months or 50,000 miles. If the vehicle is outside these warranty parameters, this Technical Service Bulletin is for informational purposes only, meaning the owner would be responsible for repair costs. All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual.

Labor operations include:

• Center cover plate remove and reinstall (both sides): 5193 1900 (associated operations) or 5193 2000 (130 TU)
• Modify longitudinal member: 5079 4199 (80 TU)
• Modify both longitudinal members: 5079 5099 (130 TU)
• Diagnostic Time (GFF): No allowance (0 TU)
• Road tests prior to service procedure: 0121 0099 (30 TU)
• Road test after service procedure: 0121 0004 (10 TU)

Claim comments should reference "As per TSB #2061672/2".

Important Warnings

• If initial diagnostic steps do not resolve or change the noise characteristics, the repair outlined in TSB 2061672/2 will not be effective, and further diagnosis is necessary.
• It is crucial to replace all loosened subframe bolts at the conclusion of the entire repair, as specified in the repair manual.
• If your vehicle is outside the warranty period (48 months/50,000 miles), this Technical Service Bulletin serves as information only, and the repair may not be covered by Audi.

NHTSA ID: 10201542