Mark LT 2WD V8-5.4L VIN 5 (2007)
5. Inspect for pre-ignition, identified by melted electrodes and a possibly damaged insulator. Metallic deposits on the insulator indicate engine
damage. This may be caused by incorrect ignition timing, wrong type of fuel or the unauthorized installation of a Heli-coil insert in place of the
spark plug threads.
^
Install a new spark plug.
6. Inspect for overheating, identified by white or light gray spots and with bluish-burnt appearance of electrodes. This is caused by engine
overheating, 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.
7. Inspect for fused deposits, identified by melted or spotty deposits resembling bubbles or blisters. These are caused by sudden acceleration.
^
Clean the spark plug.
