how do ignition coils fail

Have you ever wondered how ignition coils work and what can cause them to fail? Ignition coils play a crucial role in the functioning of your vehicle's engine. They are responsible for creating the high-voltage spark required to ignite the air-fuel mixture in the combustion chamber, which ultimately powers your car. Without a fully functioning ignition coil, your engine's performance can be severely impacted.

In this article, we will take a closer look at ignition coil failure, exploring the reasons behind it, how to detect it, and potential solutions. So, let's dive in!

1. Understanding Ignition Coils: An Overview

2. Common Causes of Ignition Coil Failure

3. Symptoms of a Failing Ignition Coil

4. Diagnosing Ignition Coil Issues

5. Fixing Ignition Coil Problems

Understanding Ignition Coils: An Overview

Ignition coils are electrical devices that convert low voltage from your car's battery into high voltage needed to create a spark. This spark is transferred to the spark plugs, igniting the air-fuel mixture and initiating the combustion process. Typically, modern vehicles have one ignition coil per cylinder, while older models may employ a single coil for the entire engine.

Common Causes of Ignition Coil Failure

1. Age and Wear: Ignition coils, like any other vehicle component, have a limited lifespan. Over time, they may wear out and lose their efficiency. The insulation around the coil windings may also degrade, leading to internal shorts or open circuits.

2. Overheating: Ignition coils generate heat during operation. If proper cooling mechanisms fail, or if the engine operating temperature exceeds normal limits due to a faulty cooling system, the excessive heat can wear down the coil faster, leading to failure.

3. Voltage Spikes: Abrupt voltage spikes caused by faulty alternators, defective wiring, or faulty spark plugs can overload the ignition coil. This can create excessive heat and stress, damaging the coil over time.

4. Moisture and Corrosion: Ignition coils are exposed to the elements and can get wet due to rain or moisture seeping into the engine bay. Moisture, combined with dirt and debris, can cause corrosion on the coil's electrical terminals, resulting in poor connections and eventual failure.

5. Poor Maintenance: Regular vehicle maintenance, including checking and replacing worn-out ignition system components, is crucial for ensuring the longevity of ignition coils. Neglecting maintenance can lead to accelerated wear and early failure.

Symptoms of a Failing Ignition Coil

Detecting a failing ignition coil early on is essential to prevent further damage. Look out for these common signs:

1. Misfires: If you experience rough idling, engine misfires, or a noticeable drop in performance, it could indicate a failing ignition coil.

2. Difficulty Starting: A faulty ignition coil may struggle to provide the necessary spark to start your engine, resulting in extended cranking time or failed starts.

3. Reduced Gas Mileage: Ignition coil issues can lead to an improper air-fuel mixture, negatively impacting fuel efficiency. If you notice a sudden decrease in gas mileage, it might be worth investigating your ignition system.

4. Illuminated Check Engine Light: When an ignition coil fails, it often triggers the vehicle's onboard diagnostic system, causing the check engine light to illuminate.

5. Stalling: A failing ignition coil can cause intermittent stalling or engine shutdowns, leading to potentially hazardous situations, especially while driving at high speeds or in heavy traffic.

Diagnosing Ignition Coil Issues

Diagnosing ignition coil problems requires a combination of visual inspection, physical testing, and the use of diagnostic tools such as an oscilloscope or a scan tool. Here are a few steps to get you started:

1. Visual Inspection: Check the ignition coil for visible signs of damage or wear, including cracks, corrosion, or oil residue. Ensure that connections are secure and free from debris.

2. Resistive Testing: Use a digital multimeter to measure the resistance of the coil's primary and secondary windings. Compare the readings to the manufacturer's specifications.

3. Secondary Voltage Test: Perform a secondary voltage test using an oscilloscope or a spark tester. This will help identify irregularities in the spark pattern and voltage output.

4. Scan Tool Diagnostics: Connect a scan tool to your vehicle's OBD-II port to retrieve any diagnostic trouble codes (DTCs). DTCs associated with ignition coil failure can guide you in identifying the problem cylinder(s).

Fixing Ignition Coil Problems

If you suspect an ignition coil failure, it is recommended to replace the faulty coil promptly. Here's a step-by-step guide:

1. Locate the Faulty Ignition Coil: Depending on your vehicle's configuration, the ignition coil(s) might be accessible on top of the engine or mounted directly on the spark plugs.

2. Disconnect Battery: Before starting any repair work, disconnect the negative terminal of your vehicle's battery to ensure electrical safety during the replacement process.

3. Remove and Replace: Carefully remove the faulty ignition coil, paying attention to any mounting screws or connectors. Install the new coil exactly as the old one was removed, ensuring proper connection and secure mounting.

4. Test and Verify: After replacing the ignition coil, perform a secondary voltage test or use a scan tool to clear any stored DTCs and verify that the issue has been resolved.

In conclusion, ignition coil failure can happen due to a variety of reasons, but regular maintenance and early detection of symptoms can help mitigate these issues. By understanding the causes, recognizing the signs, and following the appropriate diagnostic and repair procedures, you can ensure the smooth functioning of your vehicle's ignition system. Remember, a healthy ignition coil is essential for a reliable and efficient engine performance.