Home
Share
Quick Summary: An ignition coil(also called a spark coil, spark plug coil, or car coil) is an automotive induction transformer that converts a 12V battery current into high voltage (up to 50,000V). This creates the electric spark at the spark plug to ignite the engine's air-fuel mixture.
1. Ignition Coil vs. Coil Pack vs. Spark Plug
Diagram: Internal Structure of an Ignition Coil
- Ignition Coil / Spark Coil: The single component that generates high voltage to create a spark.
- Coil Pack: A single cluster containing multiple ignition coils packaged together for several cylinders.
- Spark Plug: Receives the high voltage from the coil to produce the actual combustion spark inside the cylinder.
2. Common Types of Car Ignition Coils
- Coil-on-Plug (COP): One individual coil mounted directly on top of each spark plug. (Most common in modern vehicles)
- Coil Packs: A multi-coil unit serving multiple engine cylinders via spark plug wires.
- Canister Coil: A traditional single central coil used in older mechanical distributor systems.
Coil-on-Plug (COP) Installed in Engine Bay
3. How Many Coils Does a Car Have?
- COP System: 1 coil per cylinder (e.g., 4 coils for 4-cylinder, 6 for V6).
- Coil Pack System: 1 coil pack containing 2 to 4 built-in units.
- Distributor System: 1 single central coil.
4. Symptoms of a Bad Ignition Coil
- Engine misfires, rough idling & shaking
- Check Engine Light (e.g., Code P0300/P0301)
- Hard starting or won't start
- Reduced power & high fuel consumption
Next Article
