GM 12681660
Spark Plug

The first step to replace a Spark Plug involves removing ignition coils followed by appropriate safety equipment including safety glasses along with compressed air precautions. Clear the Spark Plug recess area to stop dirt along with foreign debris from entering the cylinder block so it does not damage engine parts or soil the threads. A thread chaser should be used to remove contaminants touching the threads. The air compressor should be used to clean Spark Plug cavity while waiting for the engine temperature to drop to prevent thread locking during Spark Plug removal. The new Spark Plug installation requires using only vehicle-specified plugs that match the required temperature range since using incorrect plugs could cause severe engine damage. A round feeler gauge should measure the gap of new and reconditioned spark plugs to verify correct gap size according to specifications. Placing the Spark Plug thread into the Cylinder Head should be easy while making sure it reaches full seating using a thread chaser to prevent thread damage or overheating from improper seating or cross-threading. Follow installation of the Spark Plug by tightening it to 20 nm (15 lb ft) before putting back the Ignition Coil(s).

Replace a Spark Plug by starting with Ignition Coil removal together with protective eyewear and proper compressed air safety steps. Valve the recess area for the Spark Plug by using a thread chaser to remove contaminants from the threads because any foreign material entering the Cylinder Head would potentially damage the engine. The engine must reach a safe operating temperature after compressed air removes debris from the Spark Plug cavity before attempting to remove the plug to prevent threaded damage. Use only the spark plugs recommended for the vehicle when installing a new Spark Plug to prevent engine damage from sparks of the incorrect temperature range. A round feeler gauge should check the newly installed and rebuilt spark plugs to verify their proper gap measurement follows the Spark Plug gap specification. A thread chaser should be used to check that the Spark Plug threads without issues and reaches total installation depth without creating cross-threading damage that could cause overheating. Follow the manufacturer instructions to install and tighten the Spark Plug until it reaches 20 nm (15 lb ft). Afterward, reinstall all the ignition coils.

The spark plug threads should smoothly go into the cylinder head and be fully seated.