GM Service Manual Online
For 1990-2009 cars only
    • Allow the engine to cool before removing the spark plugs. Attempting to remove spark plugs from a hot engine may cause the spark plugs to seize, causing damage to the cylinder head threads.
    • Clean the spark plug recess area before removing the spark plug. Failure to do so can result in engine damage due to dirt or foreign material entering the cylinder head, or in contamination of the cylinder head threads. Contaminated threads may prevent proper seating of the new spark plug.
    • Use only the spark plug specified for this engine. The spark plug gap must be checked using a wire-type gauge before installation. Refer to General Information.
    • The tachometer terminal must never be allowed to touch ground, as damage to the PCM and/or ignition coil can result.
    • The material used to construct spark plug wires is very soft. This wire will withstand more heat and carry a higher voltage, but chaffing and cutting become easier. The spark plug wires must be routed correctly to prevent chaffing or cutting. Refer to Spark Plug Wires Not Operating Properly . When removing a spark plug wire from a spark plug, twist the boot on the spark plug one-half turn while pulling on the boot.