my BMW 5 Series G30/G31 (2017-2024) has a strange noise coming from the rear, what could it be?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Park the vehicle on a flat surface and engage the parking brake.
• Wear safety gloves and eyewear.

2. Inspect and Replace Rear Brake Components

1. Remove Rear Wheel:

   • Loosen lug nuts before lifting the vehicle.
   • Use a jack to raise the rear of the vehicle and secure with jack stands.
   • Completely remove the lug nuts and take off the wheel.

2. Inspect Brake Pads and Rotors:

   • Remove the caliper bolts and slide the caliper off the rotor.
   • Inspect brake pads for thickness; replace if worn below 3mm.
   • Check the rotor surface for grooves or scoring; replace if necessary.

3. Install New Brake Pads/Rotors:

   • If replacing, install new brake pads and/or rotors.
   • Reattach the caliper and torque the bolts to the manufacturer’s specifications (typically around 25-30 Nm).
   • Reinstall the wheel and torque lug nuts to the specified value (typically around 120 Nm).

3. Inspect and Replace Suspension Components

1. Visual Inspection:

   • Check for any visible damage or looseness in the shock absorbers, springs, and control arms.
   • Look for signs of fluid leaks from shock absorbers.

2. Replace Damaged Components:

   • If any suspension parts are damaged (e.g., shock absorbers), remove the old components.
   • Install new suspension parts and torque to manufacturer specifications.

4. Check and Secure Exhaust Components

1. Inspect Exhaust System:
   • Look for loose hangers or damaged sections in the exhaust system.
   • Tighten any loose bolts or replace broken hangers.

5. Test Drive

• Lower the vehicle and take it for a test drive to ensure the noise has been resolved.