Spark Plug: Description and Operation

Spark Plug:

The spark plugs used on the 4.9L engine have platinum pads welded to the electrodes. These pads extend the spark plug life to 100,000 miles.

4.9L spark plugs are a resistor type tapered seat design. No gasket is used on these tapered seat plugs.

Normal service is assumed to be a mixture of idling, slow speed, and high speed driving. Occasional or intermittent high speed driving is needed for good spark plug performance because it gives increased combustion heat that burns away any excess deposits of carbon or oxides that have built up from frequent idling or continual stop-and-go driving. Spark plug type is 41-929 and gap size is 0.060 inch. Always replace plugs with current one listed.