why does my Volkswagen Golf Eighth Generation (2020-present) have a rough idle when stopped

Solution

1. Preparation

• Gather tools: OBD-II scanner, socket set, torque wrench, fuel pressure gauge, cleaning supplies.
• Disconnect the battery to ensure safety during repairs.

2. Clean the Throttle Body

• Remove the intake duct connected to the throttle body using a socket set.
• Use a throttle body cleaner and a soft cloth to clean the throttle plate and surrounding areas.
• Reattach the intake duct securely.

3. Inspect and Replace Spark Plugs

• Remove the ignition coil(s) using a socket set, noting the order of removal.
• Take out the old spark plugs with a spark plug socket.
• Inspect for wear or carbon buildup; replace if necessary with OEM-spec spark plugs.
• Reinstall the ignition coil(s) ensuring they are seated properly.

4. Check and Seal Vacuum Leaks

• Visually inspect all vacuum lines connected to the intake manifold.
• Replace any cracked or damaged hoses.
• Use vacuum line clamps to secure any loose connections.

5. Test Fuel Pressure

• Connect a fuel pressure gauge to the fuel rail’s test port.
• Turn the ignition on (but do not start the engine) to check for initial fuel pressure.
• Compare it against manufacturer specifications; if low, check the fuel pump and filter.