Skoda Octavia NFL (2020-Present) rough idle when stopped, what could it be?

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Disconnect the battery to ensure safety.
• Allow the engine to cool down if it has been running.

2. Inspect and Replace Spark Plugs

• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Disconnect the ignition coils by unplugging the connectors and removing the bolts.
  3. Use a spark plug socket to carefully remove each spark plug.
  4. Inspect spark plugs for wear; replace if necessary with OEM or equivalent parts.
  5. Reinstall the new or cleaned spark plugs, torque to manufacturer specifications (typically 15-20 Nm).
  6. Reattach the ignition coils and engine cover.

3. Clean or Replace Idle Air Control Valve (IAC)

• Sub-steps:
  1. Locate the IAC valve, typically mounted on or near the throttle body.
  2. Disconnect the electrical connector and remove the mounting screws.
  3. Inspect for carbon buildup; clean with throttle body cleaner or replace if damaged.
  4. Reinstall the IAC valve and reconnect the electrical connector.

4. Check for Vacuum Leaks

• Sub-steps:
  1. Use a vacuum gauge to check for proper levels while the engine is idling.
  2. Inspect all vacuum hoses for cracks or disconnections; replace any damaged hoses.
  3. Tighten any loose connections to ensure no air is leaking into the system.

5. Inspect Fuel System

• Sub-steps:
  1. Check fuel pressure using a fuel pressure gauge; compare readings to manufacturer specifications.
  2. Inspect fuel injectors for clogs; clean or replace if necessary.
  3. Ensure the fuel pump is functioning correctly and no fuel lines are leaking.