Spark Plugs
Symptoms Of Bad Spark Plugs
Spark plugs receive power from the distributor and/or ignition coil(s) that they use to create the spark needed for combustion, and are crucial to starting and your vehicle's engine. The spark plugs on your car consist of a center electrode that receives power, and a ground electrode that completes the circuit to arc, making a spark. Without healthy spark plugs, your car will not start or move or may experience a loss in performance or efficiency. Although they're designed for lasting performance - around 80 to 100 thousand miles - spark plugs wear out over time as the electrode material degrades. If the spark plug electrode wears down too far, the gap may become too wide for electricity to arc, resulting in a weak spark or a complete lack of spark, and an engine that will not start. Additionally, pre-combustion can cause the spark plug electrodes to fail prematurely. Spark plugs may also be fouled by overly-rich fuel mixtures or oil contamination, which can cause engine misfires and allow the spark plug to only operate intermittently. A non-working spark plug can also be caused by a failing ignition coil, spark plug wire or boot, or a damaged connection from constant heat and long-term use. This damage can affect your vehicle's ability to ignite the fuel mixture and prevent you from starting your vehicle or running the engine. Signs of a bad spark plug include misfiring if your vehicle has difficulty starting, a rough or loud idle, reduced fuel economy, trouble starting your car or accelerating, an illuminated Check Engine light, and more. Replacing spark plugs is part of a regular tune-up, so if your spark plugs need to be replaced, you should also consider replacing the spark plug wires or coil boots to restore optimal performance. If you're unsure of what spark plugs your car needs, check out our helpful articles on how to choose the right spark plugs, how to set spark plug gap, and much more. Shop O'Reilly Auto Parts for the best spark plugs, spark plug wires, coil boots, and other spark plug and ignition system parts for a complete tune-up or repair.