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. See Fig 1. Spark plugs with this condition must be replaced.

Fig 1: Chipped Electrode Insulator

Courtesy of DAIMLERCHRYSLER CORP.

1 - GROUND ELECTRODE

2 - CENTER ELECTRODE

3 - CHIPPED INSULATOR