Spark Plug: Description and Operation

1991 Jaguar XJ-6 L6-4.0LSECTION Description and Operation

Spark Plug Construction:





CONSTRUCTION

Spark Plug Temperature:





HEAT RANGE

The spark plug provides a path for the high voltage of the secondary circuit to flow to ground. The only paths for this voltage are through the ground electrode and center electrode across the spark gap. The spark produced when the electrical voltage jumps the gap ignites the air/fuel mixture in the cylinder. The temperature of the spark plug is determined by the length of the insulator and the size of the heatsink area. The longer the insulator is, the smaller the heatsink area will be and this will cause the spark plug to be hotter. The center electrode temperature ranges from a low of 392° F (200° C) at 10 mph to a high of 1472° F (800° C) at 80 mph.
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.