how to fix rough idle in Volkswagen Golf Seventh Generation (2013-2020)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool before working on it.

2. Inspect and Replace Spark Plugs

• Sub-steps:
  1. Remove the engine cover (if applicable) using a socket set.
  2. Disconnect the ignition coil connectors.
  3. Remove the ignition coils from the spark plugs.
  4. Use a spark plug socket to carefully remove the spark plugs.
  5. Inspect the spark plugs for wear or fouling. Replace with OEM specifications if necessary.
  6. Install new spark plugs by hand, then torque to manufacturer's specifications (typically around 20 Nm).
  7. Reinstall the ignition coils and reconnect the connectors.

3. Check and Clean the Idle Air Control Valve (IAC)

• Sub-steps:
  1. Locate the IAC valve, usually found on or near the throttle body.
  2. Disconnect the electrical connector and remove the mounting bolts.
  3. Clean the valve and its port with throttle body cleaner.
  4. Reinstall the IAC valve and reconnect the electrical connector.

4. Inspect and Repair the Vacuum Lines

• Sub-steps:
  1. Visually inspect all vacuum lines connected to the intake manifold for cracks or disconnections.
  2. Replace any damaged vacuum lines with OEM parts.
  3. Ensure all connections are secure and free from leaks.

5. Fuel System Maintenance

• Sub-steps:
  1. Check the fuel pressure using a fuel pressure gauge; it should meet OEM specifications.
  2. If low, inspect the fuel filter for clogs and replace if necessary.
  3. Clean or replace fuel injectors as needed using a professional cleaning kit or replace them if faulty.

6. Reassemble and Reset

• Sub-steps:
  1. Reassemble any components removed during repairs.
  2. Reconnect the battery.
  3. Clear any error codes with the OBD-II scanner.