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ignition coils
Posted in: NEW Auto Parts Blog

Here’s What You Should Know About the Ignition Coils

What are ignition coils ?

Ignition coils are crucial components in the ignition system of internal combustion engines, such as those found in cars and motorcycles. Their primary function is to convert the low voltage from the battery into the high voltage needed to ignite the air-fuel mixture in the engine’s combustion chambers.

Here’s how they work:

Voltage Conversion: The ignition coil receives low-voltage electricity from the battery, typically around 12 volts. It then steps up this voltage to a much higher level, usually between 20,000 to 50,000 volts, or even higher in some high-performance engines.

Induction: Ignition coils work on the principle of electromagnetic induction. Inside the ignition coil, there are two sets of wire windings: the primary winding and the secondary winding. When the primary winding receives the low voltage, it creates a magnetic field around it.

Magnetic Field Collapse: When the flow of current to the primary winding is interrupted, such as by the opening of the ignition points or the firing of the ignition coil in electronic ignition systems, the magnetic field collapses rapidly. This collapse induces a high voltage in the secondary winding due to electromagnetic induction.

High Voltage Output: The high-voltage output from the secondary winding is then sent to the spark plugs, where it jumps the gap between the electrodes, creating a spark. This spark ignites the compressed air-fuel mixture in the engine’s cylinders, causing combustion and powering the engine.

In modern engines, ignition coils are often integrated into the engine’s ignition system, which may include electronic controls to precisely time the spark and improve engine performance and fuel efficiency.

How long do ignition coils last ?

The lifespan of ignition coils can vary depending on several factors, including the quality of the component, driving conditions, maintenance, and environmental factors. Generally, ignition coils are designed to last for a considerable amount of time, often tens of thousands of miles or several years. However, they can fail prematurely due to various reasons such as:

  • Wear and Tear: Over time, the internal components of the ignition coil, such as the insulation and windings, can degrade due to heat, vibration, and electrical stress.
  • Contaminants: Exposure to moisture, dirt, oil, and other contaminants can accelerate the degradation of the ignition coil components, leading to premature failure.
  • Overheating: Excessive heat, often caused by engine overheating or poor airflow around the ignition coil, can cause insulation breakdown and shorten the coil’s lifespan.
  • Electrical Issues: Voltage spikes, excessive current, or other electrical issues within the vehicle’s electrical system can damage the ignition coil and cause it to fail.
  • Poor Maintenance: Neglecting regular maintenance, such as replacing worn-out spark plugs or faulty ignition wires, can put additional strain on the ignition coil and contribute to its early failure.

In general, most vehicles may not need ignition coil replacement during their lifetime if they are well-maintained and driven under normal conditions. However, if you notice symptoms of ignition coil failure, such as engine misfires, rough idle, or difficulty starting the engine, it’s essential to have the ignition system inspected by a qualified mechanic, as failing ignition coils can lead to decreased engine performance and fuel efficiency.

Signs of a faulty ignition coil

Several signs can indicate a faulty ignition coil in a vehicle. Here are some common symptoms to watch out for:

  • Engine Misfires: Ignition coils play a crucial role in providing the spark needed to ignite the air-fuel mixture in the engine cylinders. A faulty ignition coil may result in sporadic or consistent engine misfires, where the engine may hesitate, jerk, or run rough.
  • Rough Idle: If an ignition coil is failing, it may cause the engine to idle roughly. You might notice the engine shaking or vibrating more than usual when the vehicle is at a standstill.
  • Difficulty Starting: A failing ignition coil can lead to difficulty starting the engine, especially when the engine is cold. You may experience extended cranking times before the engine eventually starts, or it may fail to start altogether.
  • Decreased Fuel Efficiency: Ignition coil issues can lead to incomplete combustion in the engine cylinders, resulting in decreased fuel efficiency. If you notice a sudden drop in gas mileage without any other apparent cause, a faulty ignition coil could be to blame.
  • Check Engine Light: A malfunctioning ignition coil can trigger the vehicle’s onboard diagnostics system to illuminate the check engine light. This warning light indicates that the engine control module (ECM) has detected a problem and stored a diagnostic trouble code (DTC) related to the ignition system.
  • Engine Stalling: In severe cases, a faulty ignition coil can cause the engine to stall while driving, especially under load or at higher speeds. This is a dangerous situation that requires immediate attention.

If you experience any of these symptoms, it’s essential to have the vehicle inspected by a qualified mechanic as soon as possible. Ignoring ignition coil problems can lead to further damage to the engine and other components, as well as compromised vehicle performance and safety.


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