2021-2023 BMW HVAC Groaning Noise SIB 64 04 22

Owners of various 2021-2023 BMW models, including the 2023 BMW 340i, may notice an interference or "groaning noise" emanating from the heating and air-conditioning unit located in the center of the instrument panel. This noise specifically occurs when a ventilation flap, air stratification flap, or recirculated air flap changes position. BMW has released Service Information Bulletin SIB 64 04 22 (Revision 1), which supersedes the previous bulletin SI B64 04 22 dated April 2022, to address this concern.

Symptoms

The primary symptom is an audible "interference noise" or "groaning noise" originating from the heating and air-conditioning unit. This sound is directly linked to the movement of internal flaps within the system, such as the ventilation flap, air stratification flap, or recirculated air flap.

Cause

The root causes identified for this groaning noise are:

• Contamination: Debris or foreign material can lead to decreased lubrication within the kinematics unit, which is located behind the servomotors controlling the ventilation, air stratification, and recirculated air flaps.
• Incorrect Tolerances: Manufacturing variances or incorrect tolerances within the kinematics unit itself can also contribute to the noise.

Repair Procedure Summary

To resolve the 2023 BMW 340i HVAC groaning noise, technicians will follow a specific procedure outlined in SIB 64 04 22. The repair involves accessing and servicing the kinematics units responsible for flap movement:

1. Instrument Panel Support Removal: The first step requires removing the instrument panel support. This is done by following specific repair instructions (51 45 075).
2. Servomotor Removal: Once the instrument panel support is out, all ventilation flap, air stratification flap, and recirculated air flap servomotors are removed. Depending on the vehicle model, there are either two or three servomotors. For some variants, the air conditioning system's piping may cover assembly bolts, necessitating the evacuation of refrigerant before servomotor removal.
3. Kinematics Unit Service: The relevant kinematics unit, located directly behind the servomotors, is then removed. The old grease on the gate disc of the kinematics is cleaned off using a clean cloth, and new Unisilkon TK M1011 grease is applied.
4. Reassembly and Testing: After cleaning and regreasing, the vehicle is reassembled, and the heating and air-conditioning system is tested to ensure the noise has been eliminated.

Required Tools or Parts

For the repair, specific materials are required:

• Unisilkon TK M1011 (50g/1.76 ounces): Part Number 83 19 2 240 251. This specialized grease is used to relubricate the kinematics unit.
• BMW Group R-1234YF (10lb/160oz): Part Number 83 19 2 446 563. This refrigerant may be needed for top-up if the AC system was evacuated during the repair.

Additional small parts, fluids, lubricants, and one-time use fasteners may be required and should be selected according to ISTA repair instructions or the Electronic Parts Catalogue.

Claim Information

This repair for the 2023 BMW 340i HVAC groaning noise is covered under the terms of the BMW New Vehicle Limited Warranty for Passenger Cars and Light Trucks. The specific Repair Code for this issue is 6411900200.

Labor operations involved may include:

• 51 45 075 / 51 45 575: Removing and installing support for the dashboard.
• 51 00 001: Localizing body noise (work time).
• 00 58 500: Diagnosis Worktime Flat Rate.
• 64 50 510: Extract, evacuate, and fill air conditioning system (if applicable).
• 51 71 999: Additional work: Strut brace (for adaptive suspension, G20 only).
• 00 72 536: Removing and installing (including greasing) kinematics for air flap control.

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Source: NHTSA ID: 10250374