How to Change Spark Plugs (VIDEO)

• Spark Plug Socket
• Ratcheting Wrench
• Socket Extensions
• Spark Plug Set
• Various Socket Sizes (optional)
• Spark Plug Gapping Tool (optional)

Tools and other supplies are available at your local auto parts store, authorized dealership, and online vendors.

Since every vehicle is different, it’s best to consult your local dealership parts department or auto parts store to source the correct spark plugs for your specific vehicle. Here is our list of the best spark plugs on the market.

As a rule of thumb, make sure the engine is cold by letting the vehicle sit for several hours or overnight. The reasoning is so you can achieve the proper torque the new spark plugs later, and more importantly…so you don’t burn your hands!

With all your tools and supplies on hand, open the hood to access your vehicle’s engine compartment. Some cars may have plastic engine covers that require removal to expose the engine.

Next, we’ll need to identify the ignition components, as they’ll lead to the location of the spark plugs in the cylinder head(s). Most vehicles nowadays use coil packs as part of the ignition system, so you’ll want to locate those too, usually located on top of the valve cover(s).

If you have a vehicle with an older ignition system, simply look for the ignition wires leading to the spark plugs themselves.

If your vehicle’s coil pack sits directly on top of the spark plug, remove the coil pack (typically secured by small bolts or nuts). As good practice, remove only a single coil pack at a time so it can be reinstalled in the same position later.

On vehicles with traditional ignition wires, you can simply tug the connectors off the spark plugs. Pay close attention to which ignition wire goes with which spark plug, or remove only one wire at a time.

With access to the spark plug itself, use your ratcheting wrench, an extension, and the spark plug socket (a deep socket with a rubber insert that holds the plug in place) to remove the old spark plug from the cylinder head. Depending on the angle, you may need an extra universal joint extension on your socket, as every engine bay has different space constraints.

With the spark plug removed, compare it to the new replacement spark plug to make sure they match. There may also be a part number on the spark plug itself for additional confirmation.

Most spark plugs come ready to install out of the box, but if they need the gap adjusted, you can use a gapping tool to adjust to the factory settings (consult your vehicle owner’s manual or authorized dealership). New spark plugs contain a special coating from the factory, so there is no need to apply any anti-seize compound to the threads before installing.

Place the new spark plug in the spark plug well and loosely hand thread it into place (this will prevent you from cross-threading the cylinder head). If you cannot do this with the spark plug alone, use the socket and extension WITHOUT the ratchet attached to make the process easier.

Once the spark plug is hand threaded into position, use your ratchet with the extension and spark plug socket to tighten the spark plug into place. Check the torque spec for your individual vehicle application. It is very important not to overtighten the plugs, as you do not want to damage the threads within the cylinder head.

After applying the proper torque value to the spark plug, you may reinstall the coil pack and/or corresponding ignition wire.

Repeat steps 2-8 for the remainder of the spark plugs within the engine. It’s usually best practice to work from the front of the engine to the rear, or from one side to the other if your vehicle has more than one cylinder head, such as boxer and “V” style engines.

Once finished, start your vehicle to ensure it is running smoothly. If the engine is running rough, check for any loose spark plugs or ignition components.