Cherokee 4WD L6-4.0L VIN S (1998)
Oil Or Ash Encrusted
If one or more spark plugs are oil or oil ash encrusted, evaluate engine condition for the cause of oil entry into that particular combustion chamber.
ELECTRODE GAP BRIDGING
Electrode Gap Bridging
Electrode gap bridging may be traced to loose deposits in the combustion chamber. These deposits accumulate on the spark plugs during
continuous stop-and-go driving. When the engine is suddenly subjected to a high torque load, deposits partially liquefy and bridge the gap between
electrodes. This short circuits the electrodes. Spark plugs with electrode gap bridging can be cleaned using standard procedures.
SCAVENGER DEPOSITS
Scavenger Deposits
