Section 16.8
Spark Plugs

The condition of the spark plug determines the high voltage level and is the single most important component in the ignition system. The size of the electrode gap, condition of the electrodes, and the amount of deposits on the electrodes all affect the life of the spark plug. The electrodes of the spark plug are made from platinum or iridium which will minimize electrode wear.‪

Replace the spark plug with a new one if the electrode wear and amount of deposits are excessive. Otherwise the spark plug can be regapped to 0.381 mm (0.015 in).‪

Note: Servicing of the spark plugs should take place while the engine is cool. This will facilitate easier removal of the spark plugs and reduce the possibility of the plug sticking in the spark plug insert contained in the cylinder head; this also ensures the correct torque and eliminates damage to the spark plug and gasket during installation of the plugs.

Section 16.8.1
Removal of Spark Plug

Remove the spark plug from the cylinder head as follows:‪

1. Remove the ignition coils. Refer to "16.3.1 Removal of Ignition Coil" .
2. Remove the plug using a 5/8 in. thin wall spark plug socket and appropriate extensions.

Section 16.8.1.1
Cleaning of Spark Plug Terminal, Ceramic Insulation, and Socket Area

Clean the spark plug terminal, ceramic insulation, and spark plug socket as follows:‪

EYE INJURY ‪
To avoid injury from flying debris when using compressed air, wear adequate eye protection (face shield or safety goggles) and do not exceed 276 kPa (40 psi) air pressure.‪

1. Remove dirt and debris with compressed air.
2. Remove oil and grease deposits.
3. Inspect the spark plug.

Section 16.8.1.2
Inspection of Spark Plug

Inspect the spark plug as follows:‪

1. Measure the spark plug gap using a 0.381 mm (0.015 in.) feeler gage.
   1. If the spark plug gap measured is not to specifications, regap the plug and reuse. Refer to "16.8.2 Installation of Spark Plug" .
   2. If the spark plug gap is within specifications, reuse the spark plug. Refer to "16.8.2 Installation of Spark Plug" .
2. Visually check the spark plugs for excessive deposits and condition of the electrode.
   1. If the spark plug has excessive deposits and electrode wear, replace the spark plug. Refer to "16.8.2 Installation of Spark Plug" .
   2. If the spark plug has no deposits nor excessive electrode wear, reuse the spark plug. Refer to "16.8.2 Installation of Spark Plug" .

Section 16.8.2
Installation of Spark Plug

Install the spark plug as follows:‪

1. Install the spark plug using a 5/8 in. thin wall socket and appropriate extensions. Torque the spark plug to 35 - 40 N·m (26-30 lb·ft).
2. Install the ignition boot.
3. Install the ignition harness. Refer to "16.7.3 Installation Ignition Coil Harness" .