Spark Plug: Service and Repair

Spark Plug Replacement (4.3L)

Removal Procedure

1. Remove the spark plug wires. Refer to Spark Plug Wire Harness Replacement.






2. Loosen each spark plug one or two turns.
- Most spark plug are best removed from wheel wells.
3. Brush or air blast away any dirt from around the spark plugs.
4. Remove the spark plugs one at a time and place each plug in a tray marked with the corresponding cylinder numbers.

Installation Procedure






1. Properly position each spark plug washer.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

2. Inspect each spark plug gap. Adjust each plug as needed. Spark plug gap: 1.524 mm (0.060 in).
- For (IRON Head-all Subsequent Installations) tighten the spark plugs to 15 Nm (11 lb ft).
- For new iron heads tighten the spark plugs to 30 Nm (22 lb ft).
3. Install the spark plug wires. Refer to Spark Plug Wire Harness Replacement.