GMC 12681664 Spark Plug Assembly, Gas Eng Ign

You can Select Your Vehicle to check if 12681664 fits your vehicle.

You will find Spark Plugs located threaded into the top (3.6L V6) or the side (3.4L V6) of each Cylinder Head, so remove the air intake duct for a 3.6L V6; otherwise, you can check it out from here! You will need specific tools including spark plug socket, extension, and gap gauge for adjusting the gaps as required. It is recommended not to start until the engine is completely cold. Examine new plugs for defects and adjust their gaps using a gauge whose measurements are provided in the gap specifications section. Carefully bend the side electrode without breaking off any porcelain insulator if required. Avoid scratching these platinum or iridium coatings on these electrodes. If your engine is a 3.6L V 6 take out ignition coils or rather untwist boots and pull them off since in case of having a 3.4 L V 6 engine remove spark plug wires by simply twisting and pulling off boots." Use compressed air around plugs in order to avoid any dirt falling into cylinders."Fit spark plug socket over plug to be removed, turn counterclockwise and then compare against chart supplied showing how engine should run." A thin coat of anti-seize compound should be applied before installing new plugs."Install a new plug into hole, thread it tight with torque wrench / ratchet using short piece rubber hose for assistance". Finally put back ignition coil or set spark plug wire on each other after you have done this process for all remaining spark plugs.

Remove one spark plug wire at a time, pulling only on the rubber boot. If available, you can use a plug wire removal tool for easier removal.

You will need a spark plug socket, ratchet, various extensions, and a gap gauge for gap adjustment. A special plug wire removal tool is optional but not mandatory. It is also recommended to use a torque wrench for properly tightening the new spark plugs.

The spark plugs on 3.4L V6 engines are located in the valleys between the camshafts, with three on each cylinder head.