What are ignition coils, why are they important to my vehicle, and what should I be aware of?

Ignition coils are specialized electrical transformers that serve as the high-voltage "heart" of your vehicle's firing system. 

What They Are

· Voltage Transformers: They take the relatively weak 12 volts from your car battery and amplify it into thousands of volts (often 15,000 to 45,000 volts).

· Direct Power: In modern "coil-on-plug" designs, each cylinder typically has its own individual coil sitting directly on top of the spark plug. 

Why They Are Important

· Igniting Combustion: Without that massive surge of voltage, your spark plugs cannot create the spark needed to ignite the air-fuel mixture in the engine.

· Fuel Efficiency and Power: A strong, consistent spark ensures fuel burns completely, which maximizes engine performance and prevents your car from "guzzling" gas.

· Catalytic Converter Protection:  Faulty coils can lead to unburned fuel entering your exhaust system, which can cause your catalytic converter—one of the most expensive parts of a car—to overheat and fail. 

What to Be Aware Of

· Life Expectancy: They generally last between 100,000 and 200,000 miles. However, high engine heat and excessive vibration can cause them to fail earlier.

· Misfire Symptoms: A failing coil often causes a "misfire," which feels like a sudden jerk, stutter, or shake, especially when you are accelerating or idling at a stop.

· Check Engine Light: This is often the first warning sign. A flashing light usually indicates a severe misfire that needs immediate attention.

· The "Spark Plug Connection":  Worn-out spark plugs are the #1 killer of ignition coils. When a spark plug is old, the coil has to work much harder to jump the gap, leading to internal overheating and burnout.