Spark Plug: Service and Repair

Spark Plug Replacement

Removal Procedure

Notice: This engine has aluminum cylinder heads. Do not remove the spark plugs from a hot engine, allow it to cool first. Removing the spark plugs from a hot engine may cause spark plug thread damage or cylinder head damage.

1. Disconnect the negative battery cable.

Notice: Note the spark plug wire harness routing during harness removal. Improper routing during installation can cause the following conditions:

^ Radio noise

^ Ignition noise

^ Spark plug crossfiring

^ Ground lead shorts Cutting and chaffing of the wires

2. Remove the spark plug wire harnesses. Refer to Spark Plug Wire / Service and Repair.

3. Clean away all dirt and debris from the spark plug recess areas.

4. Remove the left side spark plugs.

5. Remove the right side spark plugs.

Installation Procedure

1. Ensure that the spark plug threads and the cylinder heads are clean.

2. Inspect the spark plug gap. The correct Spark Plug gap is 1.27 mm (0.050 inch). Adjust as needed.

Notice: Be sure the spark plug threads smoothly into cylinder head and is fully seated. Use a thread chaser if necessary to clean threads in cylinder head. Cross-threading or failing to fully seat spark plug can cause overheating of plug, exhaust blow-by, or thread damage. Follow recommended torque specifications carefully. Over or under-tightening can also cause severe damage to engine or spark plug.

3. Install the spark plugs into the cylinder head finger tight. Then tighten the spark plugs to specifications. Tighten the spark plugs to 20 Nm (15 lb ft).