Spark Plugs: Installation

CAUTION: Be sure that the spark plug threads smoothly into the cylinder head and the spark plug is fully seated. Use a thread chaser, if necessary, to clean threads in the cylinder head. Cross-threading or failing to fully seat the spark plug can cause overheating of the plug, exhaust blow-by, or thread damage.

Measure the spark plug gap on the spark plugs to be installed. Compare the measurement to the gap specifications. See SPARK PLUGS under IGNITION SYSTEMS in SERVICE & ADJUSTMENT SPECIFICATIONS - CTS, DEVILLE & SEVILLE article. Install the spark plugs to the engine. Tighten the spark plugs to specification. See TORQUE SPECIFICATIONS . Install the spark plug boots to the ignition coil assembly. See ELECTRONIC IGNITION MODULES .