Dakota 2WD V6-239 3.9L Magnum (1996)
Spark Plug: Testing and Inspection
Broken, Cracked or Chipped Insulator
Chipped Electrode Insulator
A chipped electrode insulator usually results from bending the center electrode while adjusting the spark plug electrode gap. Under certain conditions,
severe detonation can also separate the insulator from the center electrode. Spark plugs with this condition must be replaced.