Posted on 9/25/2026
Cooler weather can make weak ignition parts easier to notice. An engine that started and ran fine through summer may start cranking longer, idle rougher, or hesitating more once morning temperatures drop. Spark plugs do not usually fail all at once. They wear gradually, and the ignition system has to work harder as the gap grows and deposits build up. Before fall turns into colder weather, these five signs can tell you the plugs deserve a closer look. 1. The Engine Is Harder to Start in the Morning A worn spark plug needs more voltage to create a strong spark. When the engine is cold, fuel does not vaporize as easily, so the ignition system has to do a better job of lighting the mixture. If the engine takes longer to start than it used to, especially first thing in the morning, worn plugs can be part of the problem. At our shop, we still check battery condition, fuel delivery, and other starting-system components because slow starting can have more than ... read more