How to Identify the Quality of an Automotive Ignition Coil?
2 Answers
Replace the suspected faulty ignition coil with a known good one; if the issue disappears, it indicates the ignition coil is faulty. Use a multimeter to measure the resistance of the primary and secondary windings. If the measured resistance is infinite, it indicates a short circuit in the winding. If the resistance is too high or too low, it suggests poor contact or inter-turn short circuits in the winding.
I usually enjoy handling car issues myself, and identifying the condition of ignition coils is quite important. If an ignition coil is faulty, the engine may shake, have poor acceleration, or even increased fuel consumption. You can start by observing symptoms: at idle, if the engine vibrates noticeably or runs unevenly, there might be an issue. Visually inspect the coil for cracks, burn marks, or signs of oil leakage. At home, use a multimeter to test the resistance values—typically, primary resistance should be between 1-3 kilohms, and secondary resistance between 7-15 kilohms. If the values are outside this range or vary significantly, replacement is needed. You can also remove the spark plug cap to check spark intensity; a weak, pale-colored spark indicates a problem. Compare coil values across different cylinders to assess consistency. If possible, swap coil positions to identify which cylinder is failing. Don’t delay—worn coils can lead to bigger engine issues. Regular spark plug maintenance can help extend coil lifespan.