Common signs of a failing ignition coil for a Pontiac Grand Am or other vehicle include hard starting, engine misfiring, noisy engine, stalling, backfiring and poor fuel economy. The ignition coil is an integral component of a vehicle's ignition system and responsible for supplying current to spark plugs to ignite the fuel inside the engine's combustion chamber. Malfunctioning ignition coils fail to generate sufficient voltage to fire spark plugs properly.
Low voltage supply to the spark plugs leads to lower percentages of air and fuel mixture being ignited. This causes the engine to consume more fuel to complete the compression and power stroke cycle. This early stage of a failing ignition coil is characterized by thick black smoke emissions, sluggish acceleration and a noisy engine.
Low and intermittent idling speeds are also signs of bad ignition coils and engine overheating. Since failing ignition coils no longer supply the correct voltage to ignite fuel, engine components work harder to keep it running.
Failing ignition coils have an effect because the engine needs to work a lot harder to push the vehicle forward. This can cause the engine to overheat and push the coil to quit and stall the vehicle.
Proper maintenance plays an important role in preventing premature ignition coil failure, according to exploreB2B. Running a car with a bad ignition coil for extended periods of time can lead to other ignition system component damage.