What is a common indication of a faulty ignition coil?

A common indication of a faulty ignition coil is the absence of spark at the spark plug. The ignition coil is a critical component in the engine's ignition system, responsible for converting the battery's low voltage into the high voltage needed to create a spark. If the ignition coil fails, it can prevent the necessary voltage from reaching the spark plug, resulting in no spark. Without this spark, the air-fuel mixture in the engine cylinder cannot ignite, leading to engine starting issues or misfires. This directly affects the engine's ability to run smoothly and efficiently.

In contrast, while inconsistent power output, frequent engine stalling, and excessive fuel consumption may also be symptoms of various ignition or engine issues, they do not specifically signify the complete absence of spark that characterizes a faulty ignition coil. Therefore, the presence of no spark at the spark plug is a clear and direct indicator of a problem with the ignition coil.