2025 BMW X3 Rear Muffler Rattling Noise TSB

BMW has released Service Information Bulletin SIB 18 02 25, dated July 10, 2025, to address a common concern for owners of the 2025 BMW X3 equipped with the B48P 4-cylinder engine (model code G45). This bulletin specifically targets a 2025 BMW X3 rattling noise emanating from the rear muffler.

This issue typically manifests after the engine has warmed up. Technicians have observed that the rattling noise often disappears when the vehicle is raised on a lift, suggesting a specific mechanical cause that is resolved when the exhaust system is no longer under normal load.

Symptoms

Owners may notice a distinct rattling noise coming from the rear of their 2025 BMW X3. This noise is most prominent after the engine has reached its operating temperature. If you experience a 2025 BMW X3 rattling noise, it's advisable to have it inspected.

Cause

The root cause identified for this 2025 BMW X3 rattling noise is insufficient clearance. Specifically, the gap between the heat shield and the rear muffler may be too small, leading to contact and the resulting rattling sound.

OEM Fault Label

BMW identifies this specific issue with the defect code 1830900100, labeled as "G45 B48P Rear silencers rattle." This code helps technicians accurately diagnose and address the problem.

Repair Procedure Summary

The repair outlined in SIB 18 02 25 involves installing 3 mm washers to increase the clearance between the vehicle body and the rear exhaust hangers. The procedure requires raising the vehicle on a lift to access the exhaust system.

Technicians will first remove a protective cover, secured by a screw tightened to 3 Nm. Next, the nut holding the rear exhaust hanger is removed. A 3 mm washer is then installed onto the hanger; a small amount of sealant can be used to hold the washer in place during installation. Finally, the hanger is reinstalled, and the nut is replaced and tightened to a torque of 19 Nm. This process creates a necessary gap between the body and the hanger, resolving the rattling. This repair must be performed on both the left and right sides of the exhaust system.

Required Tools or Parts

To perform this repair, specific parts are required:

• Part Number: 07 14 7201571
  • Description: Washer (A8, 4x25)
  • Quantity: 2
• Part Number: 07 11 9906089
  • Description: Collar nut (M8)
  • Quantity: 2

Owner Action

If you are experiencing a 2025 BMW X3 rattling noise from your rear muffler, you should contact your authorized BMW dealer to schedule a service appointment. This repair is covered one-time under the terms of the BMW New Vehicle Limited Warranty for Passenger Cars and Light Trucks.

Source: NHTSA ID 11020907