why is my BMW 3 Series G20/G21 (2019-2024) making a loud exhaust noise?

Solution

1. Preparation

• Tools Required: Socket set, jack and jack stands, OBD-II scanner, soapy water solution
• Safety Warnings: Allow the engine to cool before beginning work. Wear safety goggles and gloves.

2. Inspect and Repair Exhaust Components

• Check for Leaks:
  • Start the engine and listen for abnormal sounds.
  • Apply soapy water to exhaust joints and connections. Bubbles indicate leaks.
• Repair or Replace:
  • If leaks are detected, tighten loose connections or replace damaged gaskets.
  • For cracked or rusted sections, cut out the damaged area using a saw and replace it with a new section of exhaust pipe.
  • If the muffler is damaged, remove it by unbolting the exhaust clamps and replacing it with a new muffler.

3. Replace Exhaust Hangers

• Remove the old exhaust hangers by detaching them from their mounting points.
• Install new hangers by securing them in place, ensuring the exhaust is properly supported.

4. Inspect and Replace Catalytic Converter (if necessary)

• If the catalytic converter is damaged, remove the exhaust pipe leading to it.
• Unbolt the catalytic converter from the exhaust system and replace it with a new unit, ensuring to use new gaskets.
• Reattach the exhaust pipe and tighten all bolts to the manufacturer’s specified torque values.