Skoda Octavia NFL (2020-Present) rough idle when cold, what’s causing this

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is on a level surface and the engine is off.
• Disconnect the battery before beginning work on electrical components.

2. Replace Spark Plugs

• Remove the ignition coils:
  • Use a socket set to unbolt the ignition coils from the cylinder head.
  • Carefully pull the ignition coils straight out.
• Replace the spark plugs:
  • Use a spark plug socket to remove old spark plugs.
  • Inspect for wear (check gap and condition).
  • Install new spark plugs to manufacturer specifications (typically 25-30 Nm torque).
  • Reinstall ignition coils and secure.

3. Check and Replace Fuel Filter (if necessary)

• Locate the fuel filter:
  • Refer to the vehicle's service manual for exact location.
• Disconnect the fuel lines:
  • Use appropriate tools to relieve fuel pressure before disconnecting.
• Replace the fuel filter:
  • Install the new fuel filter in the correct orientation.
  • Reconnect fuel lines securely.

4. Clean Throttle Body

• Remove the throttle body:
  • Disconnect electrical connectors and air intake tubes.
  • Unbolt the throttle body from the intake manifold.
• Clean the throttle body:
  • Use throttle body cleaner and a soft brush to remove carbon buildup.
  • Ensure the throttle plate moves freely.
• Reinstall the throttle body and reconnect all components.

5. Replace Engine Coolant Temperature Sensor (if faulty)

• Locate the sensor:
  • Usually found near the thermostat housing.
• Remove the old sensor:
  • Disconnect the electrical connector and unscrew the sensor.
• Install the new sensor:
  • Screw in the new sensor and reconnect the electrical connector.