Silverado 3500 4WD V8-6.0L VIN U (2004)
-
Worn ignition wires
-
Incorrect spark plug gap
-
Excessive idling or slow speeds under light loads can keep spark plug temperatures so low that normal combustion deposits may not burn off.
-
Deposit fouling - Oil, coolant, or additives that include substances such as silicone, very white coating, reduces the spark plug intensity. Most
powdery deposits will not affect spark plug intensity unless they form into a glazing over the electrode.