Where Is the Spark Plug Located?

Q: Where Is the Spark Plug Typically Located?

A: The location of the spark plugs can vary depending on the number of cylinders in the engine. In a four-cylinder engine, the plugs are found on either the engine’s top or the side in a row. If we’re talking about an inline six-cylinder engine, the plugs are on the top or the side of the engine head. Finally, the spark plugs of V6 and V8-cylinder engines  are usually divided evenly across either side and will either be in the center of the head or down on the side near the exhaust.

Many Subaru models position their spark plugs on the side of their engine. This also applies to Porsche models equipped with a flat-four or a flat-six engine.

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Pro Tip: If you can find the coils or follow the spark plug wires from the distributor cap to the spark plugs, you’ve found them.

Spark plugs are a key part of the ignition system. They’re electrical devices that ignite the air-fuel mixture inside the cylinder’s combustion chamber. Because they use high voltage and generate hot electrical sparks, they wear out quickly and require replacement.

Tips On How to Access the Spark Plug

When you open the hood, look for the spark plugs on the engine. Each spark plug has either an ignition coil or a wire leading to the coil. Modern vehicles usually have an ignition coil pack for each cylinder, while older vehicles have only a single coil pack shared between its cylinders. If the spark plug has an ignition coil pack, unbolt the coil pack to reveal the plug’s top. But if the plug has a wire, carefully tug the wire.

Use a clean rag or compressed air to clean the spark plug. Next, loosen the spark plug with a socket. If the plug stays stuck, use a ratchet to loosen it.