Spark Plug: Service and Repair
Setting Spark Plug Electrode Gap:
When replacing the spark plug and 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, cross ignition of the spark plugs or short circuit the cables to ground.
CAUTION: Never attempt to file the electrodes or use a wire brush for cleaning platinum plugs. This would damage the platinum pads which would shorten spark plug life.
Never force a gap gauge between the platinum electrodes or adjust the gap on platinum spark plugs without reading the Spark Plug Gap Measurement procedures below.
Always tighten spark plugs to the specified torque. Over tightening can cause distortion resulting in a change in the spark plug gap. Overtightening can also damage the cylinder head. Tighten spark plugs to 28 N.m (20 ft. lbs.) torque.
Due to the engine packaging environment for these engines, extreme care should be used when installing the spark plugs to avoid cross threading problems.
SPARK PLUG GAP MEASUREMENT
CAUTION: The Platinum pads can be damaged during the measurement of checking the gap if extreme care is not used.
- Use Only a taper gap gauge.
- Never force the gap gauge through the platinum pads. Only apply enough force until resistance is felt.
- Never use a wire brush or spark plug cleaner machine to clean platinum spark plugs
- Use an OSHA approved air nozzle when drying gas fouled spark plugs.
Platinum Pads:
If gap adjustment is required of platinum plug, bend only the ground electrode. DO NOT TOUCH the platinum pads. Use only a proper gapping tool and check with a taper gap gauge.
Apply a very small amount of anti-seize compound to the threads when reinstalling the vehicle's original spark plugs that have been determined good. Do not apply anti-seize compound to new spark plugs.
NOTE: Anti-seize compound is electrically conductive and can cause engine misfires if not applied correctly. It is extremely important that the anti-seize compound doesn't make contact with the spark plug electrodes or ceramic insulator.
SPARK PLUG REMOVAL---#2, #4 or #6
Always remove the ignition cable by grasping at the spark plug boot turning, the boot 1/2 turn and pulling straight back in a steady motion.
1. Prior to removing the spark plug spray compressed air around the spark plug hole and the area around the spark plug.
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 Condition.
INSTALLATION
1. To avoid cross threading, start the spark plug into the cylinder head by hand.
2. Tighten spark plugs to 28 N.m (20 ft. lbs.) torque.
3. Install ignition cables over spark plugs.
SPARK PLUG REMOVAL-#1, #3 or #5
1. Disconnect negative cable from auxiliary jumper terminal.
Intake Manifold Sensors And Left Plenum And Left Plenum Support Bolt:
2. Unplug connectors from MAP and intake air temperature sensors.
3. Remove plenum support bracket bolt located rearward of MAP sensor.
Air Inlet Resonator:
4. Remove bolt holding air inlet resonator to intake plenum.
5. Loosen throttle body air inlet hose clamp.
6. Release snaps holding air cleaner housing cover to housing.
7. Remove air cleaner cover and inlet hoses from engine.
Throttle Position Sensor:
Idle Air Control Motor:
8. Unplug TPS and idle air control motor connectors.
Throttle Cable Attachment:
9. Pry retainer tab back on throttle cable and slide cable out of bracket. Remove cable from throttle lever.
10. Slide Speed control cable out of bracket, if equipped. Remove cable from throttle lever.
EGR Tube And Right Manifold Support Bolt:
11. Remove EGR tube from intake plenum.
12. Remove plenum support bracket bolt located rearward of EGR tube.
13. Remove bolts holding upper intake plenum and remove plenum.
14. Always remove the ignition cable by grasping at the spark plug boot turning, the boot 1/2 turn and pulling straight back in a steady motion.
15. Prior to removing the spark plug spray compressed air around the spark plug hole and the area around the spark plug.
16. Remove the spark plug using a quality socket with a rubber or foam insert.
17. Inspect the spark plug condition. Refer to Spark Plug Condition.
SPARK PLUG INSTALLATION
1. To avoid cross threading, start the spark plug into the cylinder head by hand.
2. Tighten spark plugs to 28 N.m (20 ft. lbs.) torque.
3. Install ignition cables over spark plugs.
4. Install new gasket and position upper intake plenum. Tighten plenum bolts to 18 N.m (13 ft. lbs.) torque.
5. Install bolts at plenum support brackets. Tighten bolts to 18 N.m (13 ft. lbs.).
6. Install EGR tube to plenum. Tighten EGR tube to intake manifold plenum screws to 11 N.m (95 in. lbs.).
7. Install throttle and speed control (if equipped) cables.
8. Attach electrical connectors to sensors.
9. Tighten air inlet tube clamps to 3 N.m ± 1 (25 ± 5 in. lbs.) torque.
10. Connect negative terminal to auxiliary jumper terminal.