All ignition coils transform a low-voltage/high-current power in the primary to high-voltage/low-current energy in the secondary. An ignition coil has no moving parts that can fail or wear out — what is moving inside an ignition coil are electrons and magnetic fields between coils of wire and metal plates cast into epoxy resin.
What kills ignition coils is location; being mounted in one of the hottest, most vibration prone and dirtiest parts of the engine.
Modern ignition coils are typically located between two camshafts on the valve cover and exposed to dirt and oil. But, even if a coil is mounted in a cool, clean and vibration-free environment, if the gap on the spark plug is not correct or there are issues with high resistance in the cylinder, it won’t take long for a coil to fail.
For the complete article from our sister publication, Underhood Service, click HERE.
