A GM V-6 engine needs to have the plugs and wires changed every 50,000 miles due to the possible wear on the plugs. As the plugs wear, they cause the vehicle to use more fuel. Changing the plugs and wires on any vehicle can be difficult, but on a GM V-6 the process is not as hard as on some other engines. This process can be completed in just under an hour.
Allow the engine to cool for an hour after driving before performing this procedure. This will ensure that no thread damage is done when removing the old plugs.
Grasp the boot for the spark plug that is closest to the passenger side and firewall of the vehicle. Wiggle this boot while pulling to remove it from the plug.
Put the 5/8-inch spark plug socket on the end of the 3-inch extension and place them on the spark plug. Make sure the plug goes all the way in the socket so that the rubber gasket grasps the plug for removal. Attach the socket wrench and loosen the plug. Some GM V-6 engines may require a 6-inch extension for the plugs on the back, but most will not.
Remove the old plug from the socket and place the new plug in the socket. Dab some anti-seize compound on the threads of the new plug. This will help to keep the plug from locking in the threads.
Thread the new plug in the spark plug hole by hand with the socket and extension. Finish tightening the new plug with the ratchet. The plug should be tightened half a turn past hand-tight. Over-tightening the plug can cause serious engine damage. Make sure not to cross-thread the new plug.
Remove the second end of the plug wire from the coil or distributor cap. Match this wire with a new plug wire. Match the wires by length. Squeeze a pea-sized amount of dielectric grease in both ends of the new wire.
Install the end of the plug wire on the distributor cap or coil. Route the wire to the spark plug and install the plug boot on the new plug. Make sure the wire boot "clicks" on the new plug.
Repeat Steps 2 through 7 for the rest of the plugs.
