how to fix P0304 cylinder 4 misfire in Volvo XC60 First Generation (2008-2017)

Learn how to diagnose and fix P0304 cylinder 4 misfire in Volvo XC60. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety during the repair process.
• Allow the engine to cool.

2. Inspect and Replace Spark Plug

• Remove the engine cover if necessary to gain access.
• Use a spark plug socket to remove the spark plug from cylinder 4.
  • Tools Required: Spark plug socket, ratchet, torque wrench
• Inspect the spark plug for wear, carbon buildup, or damage. Replace with a new spark plug if needed.
  • Torque Specification: 18 lb-ft (25 Nm) when reinstalling the spark plug.

3. Inspect and Replace Ignition Coil

• Remove the ignition coil from cylinder 4 by unscrewing it and carefully pulling it out.
• Visually inspect the ignition coil for cracks or signs of wear.
• If needed, replace the ignition coil with a new one.
  • Tools Required: Socket set, torque wrench
  • Torque Specification: 7 lb-ft (10 Nm) when reinstalling.

4. Check and Replace Fuel Injector (if necessary)

• Disconnect the fuel injector connector and use a tool to release the fuel line safely.
• Remove the fuel injector from cylinder 4.
• Inspect for clogs or damage.
• If the injector is faulty, replace it with a new one.
  • Tools Required: Fuel injector removal tool, torque wrench
  • Torque Specification: 14 lb-ft (19 Nm) for installing injector.

5. Reassemble and Clear Codes

• Reconnect all the components (spark plug, ignition coil, fuel injector).
• Reconnect the battery.
• Use an OBD-II scanner to clear the P0304 code from the system.