why does my BMW 5 Series G30/G31 (2017-2024) make a hissing noise when idling

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety during repairs.

2. Inspect and Replace Vacuum Hoses

1. Locate all vacuum hoses connected to the intake manifold and other components.
2. Check for cracks or damage: Replace any damaged hoses with OEM parts.
   • Tools Required: Vacuum hose removal tool, pliers.
   • Safety Warning: Ensure the engine is cool before working on components.

3. Inspect and Replace Intake Manifold Gasket

1. Remove the intake manifold:
   • Disconnect all electrical connectors and hoses attached to the manifold.
   • Remove any bolts securing the manifold using a torque wrench.
2. Inspect the gasket for wear or damage. Replace if necessary.
   • Tools Required: Socket set, torque wrench, gasket scraper.
3. Reinstall the intake manifold:
   • Apply the new gasket and torque the bolts to the manufacturer's specifications.

4. Clean Throttle Body

1. Remove the throttle body from the intake system:
   • Disconnect electrical connectors and hoses.
   • Unscrew the throttle body from the intake manifold.
2. Clean the throttle body using an appropriate throttle body cleaner.
   • Use a soft cloth and ensure all carbon buildup is removed.
3. Reinstall the throttle body securely.