- 10mm socket wrench
- 16mm spark plug wrench
- 1/4-inch ratchet
- 1/4-inch extension
- Spark plug gap tool
Instructions:
1. Disconnect the negative battery terminal to cut the power to your vehicle and prevent an electrical shock.
2. Open your BMW 320d’s hood to access the engine compartment.
3. Use a 10 mm socket wrench to remove the cowl to expose the spark plugs. This is the plastic black cover right on the top of the valve cover.
4. Use a 16 mm spark plug wrench to loosen and remove the spark plug wires.
5. Use the 1/4-inch ratchet, extension and 16 mm spark plug wrench to loosen and remove the old spark plugs from the cylinder head.
6. Set the gap on the new spark plugs using the spark plug gap tool. The recommended gap for the BMW 320d is 1.1 mm.
7. Hand-tighten the new spark plugs until they are snug. Then use the spark plug wrench to further tighten them. Do not overtighten.
8. Reinstall the spark plug wires and coil pack.
9. Replace the cowl.
10. Reconnect the battery terminal.
