9-2X F4-2.5L (2006)
3. Oil fouled:
Wet black deposits show excessive oil entrance into combustion chamber through worn rings and pistons or excessive clearance between valve
guides and stems.
4. Overheating:
White or light gray insulator with black or brown spots and bluish burnt electrodes indicate engine overheating. Moreover, the appearance results
from incorrect ignition timing, loose spark plugs, wrong selection of fuel, etc.
CAUTION: Avoid using a plug cleaner because of the spark plug with a platinum tip.