Wrangler L6-4.0L VIN S (2000)
Spark Plug: Service and Repair
PLUG REMOVAL
On this engine the spark plugs are located below the coil rail assembly. To gain access to any/all spark plug(s), refer to Ignition Coil,
Removal/installation.
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 Plug Conditions.
See: Testing and Inspection/Spark Plug Conditions
PLUG CLEANING
The plugs may be cleaned using commercially available spark plug cleaning equipment. After cleaning, file the center electrode flat with a small point
file or jewelers file before adjusting gap.
CAUTION: Never use a motorized wire wheel brush to clean the spark plugs. Metallic deposits will remain on the spark plug insulator and will
cause plug misfire.
PLUG GAP ADJUSTMENT
Setting Spark Plug Gap - Typical
Check the spark plug gap with a gap gauge tool. If the gap is not correct, adjust it by bending the ground electrode. Never attempt to adjust the gap by
bending the center electrode.
Spark Plug Gap
-
0.89 mm (0.035 in)
PLUG 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 in 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.
1. Start the spark plug into the cylinder head by hand to avoid cross threading.
2. Tighten the spark plugs to 35 - 41 Nm (26 - 30 ft. lbs.) torque.
3. Install coil rail. Refer to Ignition Coil, Removal/Installation.