Removal and Installation

SPARK PLUG

REMOVAL
On the 4.0L 6 cylinder engine the spark plugs are located below the coil rail assembly. To gain access to any/all spark plug(s).

1. Prior to removing the spark plug, spray compressed air around the spark plug hole and the area around the spark plug. This will help prevent foreign material from entering the combustion chamber.
2. Remove the spark plug using a quality socket with a rubber or foam insert.
3. Inspect the spark plug condition. Refer to Spark Plugs Conditions.

INSTALLATION
Always tighten spark plugs to the specified torque. Over tightening can cause distortion. This may result in a change in the spark plug gap, or a cracked porcelain insulator.

When replacing the spark plug and ignition coil cables, route the cables correctly and secure them the appropriate retainers. Failure to route the cables properly can cause the radio to reproduce ignition noise. It could cause cross ignition of the spark plugs, or short circuit the cables to ground.

Special care should be taken when installing spark plugs into the cylinder head spark plug wells. Be sure the plugs do not drop into the plug wells as electrodes can be damaged.

Always tighten spark plugs to the specified torque. Over tightening can cause distortion resulting in a change in the spark plug gap or a cracked porcelain insulator.

1. Start the spark plug into the cylinder head by hand to avoid cross threading.
2. Tighten spark plugs to 30 ± 5 N.m (22 ± 4 lbs.).
3. Install coil rail.