Coil Boot

The coil boot, also called an ignition boot or spark plug boot, connects the coil pack to the spark plug and helps insulate the voltage spark of the coil from the engine. Newer vehicles have the coil boot attached to the coil and the spark plug; this is called a coil-on-plug system. The boot is made of rubber or silicone and can wear out over time, causing arcing to the cylinder head, which can cause a misfire. When replacing the spark plugs or ignition coils, it is also a good idea to replace the boots. If your vehicle has a rough idle, misfire, or stalls, it may need some new spark plug boots. O'Reilly Auto Parts carries spark plugs, boots, and ignition coils to complete your repair.