Spark Plug: Service and Repair

REMOVAL

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.
- Use compressed air to remove any debris from the spark plug well before removing the spark plugs.





1. With a twisting, pulling motion disconnect the spark plug wire from the spark plug.





2. Squeeze the (A) locking tabs and disconnect the (B) spark plug wire from the (C) ignition coil.





3. Remove the RH spark plugs.





4. Remove the LH spark plugs.

5. Inspect the spark plugs for:





- Deposits bridging spark plug gap (A).
- Wet black deposits (oil fouling) (B).
- Dry black deposits (carbon fouling) (C).
- Overheating (D).
- Deposits fused on spark plug (E).
- Pre-ignition damage (F).
- Normal spark plug (G).

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.

1. Apply Silicone Dielectric Compound D7AZ-19A331-A or equivalent meeting Ford specification ESE-M1C171-A to inside of spark plug wire boots.





2. Adjust the spark plug gap as required.





3. Install the LH spark plugs.





4. Install the RH spark plugs.
5. Connect the spark plug wires.