Explorer 2WD V6-245 4.0L VIN X SFI (1999)
3. Remove the RH spark plugs.
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. Check for oil fouling.
^
Check for wet, black deposits on the insulator 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. Look for black, dry, fluffy carbon deposits on insulator tips, exposed shell surfaces and electrodes, 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.
