Spark Plug: Service and Repair

Spark Plug Wire Remover:

SPECIAL SERVICE TOOLS

REMOVAL







1. With a twisting motion, use the special tool to pull the ignition wire off of the spark plug.

CAUTION
^ Spark plug wires must be connected properly. Mark the spark plug wires before removing them from the spark plugs.
^ It is important to twist the spark plug wire boots while pulling upward to avoid possible damage to the spark plug wire.
^ Do not use special tool on spark plug wire boots with metal heat shields. Damage to the spark plug wire boots may occur.







2. Remove the LH spark plugs.

NOTE
^ Use compressed air to remove any debris in the spark plug well before removing the spark plugs.
^ If an original spark plug is reused, make sure it is installed in the same cylinder it was taken from. New spark plugs can be used in any cylinder.







3. Remove the RH spark plugs.

NOTE
^ Use compressed air to remove any debris in the spark plug well before removing the spark plugs.
^ If an original spark plug is reused, make sure it is installed in the same cylinder it was taken from. New spark plugs can be used in any cylinder.







4. Inspect the spark plugs for a bridged gap.
^ Check for deposit build-up closing the gap between the electrodes. Deposits are caused by oil or carbon fouling.
^ Clean the spark plug.







5. Inspect for oil fouling.
^ Check for wet, black deposits on the insulation shell bore electrodes, caused by excessive oil entering the combustion chamber through worn rings and pistons, excessive valve-to-guide clearance or worn or loose bearings.
^ Correct the oil leak concern.
^ Install a new spark plug.







6. Inspect for carbon fouling, identified by black, dry, fluffy carbon deposits on insulator tips, exposed shell surfaces and electrodes. This is caused by a spark plug with an incorrect heat range, dirty air cleaner, too rich a fuel mixture or excessive idling.
^ Clean the spark plug.







7. Inspect for normal burning.
^ Check for light tan or gray deposits on the firing tip.







8. Inspect for pre-ignition, identified by melted electrodes and a possibly damaged insulator. Metallic deposits on the insulator indicate engine damage, which may be caused by incorrect ignition timing, wrong type of fuel or the installation of a heli-coil insert in place of the spark plug threads.
^ Install a new spark plug.







9. Inspect for over-heating, identified by a white or light gray insulator with small black or gray-brown spots and with bluish-burnt appearance of electrodes. This can be caused by engine overheating, the wrong type of fuel, loose spark plugs, spark plugs with an incorrect heat range, low fuel pump pressure or incorrect ignition timing.
^ Install a new spark plug.







10. Check for fused spot deposits, identified by melted or spotty deposits resembling bubbles blisters caused by sudden acceleration.
^ Clean the spark plug.







11. Adjust the spark plug gap.

INSTALLATION

NOTE
^ If an original spark plug is reused, make sure it is placed in the same cylinder it was taken from. Replacement spark plugs can be used in any cylinder.
^ Apply Silicone Brake Caliper Grease and Dielectric Compound D7AZ-19A331-A or equivalent meeting Ford specification ESE-M1C171A to the inside of the spark plug boot of the spark plug wire.








1. Install the RH spark plugs.







2. Connect the RH spark plug wires.







3. Install the LH spark plugs.







4. Connect the LH spark plug wires.