Bad Ignition Coil Signs & Symptoms

Bad Ignition Coil Signs

The ignition coil is a part that is always attached to gasoline engine vehicles and is a very important part of running the engine. What are the symptoms when the ignition coil breaks down? What is the life, replacement time, and inspection method of an ignition coil? 

When there is a failing or bad ignition coil, the typical signs and symptoms we see are difficulty starting the engine, engine sound fluctuates when idling, engine check lamp lights up or blinks, higher fuel consumption, and acceleration problems. After reading this article, you will find out more about the symptoms, inspections, and replacements when the ignition coil breaks down. With the information, you will be able to use your vehicle for a long period without any problem.

Symptoms When the Ignition Coil is Failing

If the ignition coil has an abnormality, some symptoms will appear in the operating status of the engine. The reason is that the ignition coil is a necessary part of running the engine. Now, let me give you four examples of what kind of symptoms occurs when the ignition coil fails.

1. Difficulty in Starting the Engine

It does not matter whether you turn the key of your car, the engine will fail to start if the ignition coil is faulty. The engine usually starts immediately when you turn the key, but if it becomes difficult to start, the ignition coil may be defective. The transformer capacity of the ignition coil may be weakened. If the high voltage cannot be generated, the spark plug will not work well and it will be difficult to start the engine. 

2. Engine sound fluctuates when idling

Idling means that your engine is running, but the vehicle is not moving. If the engine sounds uneven when idling, the ignition coil may be defective. If you feel something is wrong when idling, the cause may be that the ignition coil is defective.

3. Engine check (warning light) lamp lights up or blinks

If the engine check (warning light) lamp is lit or blinking, there is a possibility that the ignition coil is defective. Check if such a warning light is lit or blinking. Even if the engine warning light comes on, the problem will not occur immediately, so first stop the car in a safe place.

Move calmly and slowly, and stop the engine when you have a place to stop. After that, we recommend that you ask the dealer or repair shop directly. When there is a problem or failure in the ignition coil, an abnormality will occur around the operation of the engine as mentioned above. In such a case, it is recommended that you check it yourself or have a dealer or maintenance shop check it.

4. Higher fuel consumption

Reduced vehicle performance and lower mileage per liter of fuel can be a sign of ignition coil failure. If the spark plug does not receive the energy needed to ignite the mixture, the vehicle will begin to consume more fuel to compensate for the spark plug’s power. 

5. Acceleration problem

You will also experience some difficulty in accelerating when your ignition coil fails. Even if you step on the accelerator, you won’t find a respite. If it is difficult to accelerate even if you step on the accelerator and you cannot feel the acceleration force, there is a problem with the ignition coil. Since the energy generated inside is reduced, the acceleration power of the car is weakened. If this happens, the ignition coil may be defective. 

What is an Ignition Coil?

The ignition coil is a two-coil transformer that generates the high voltage required to ignite a gasoline engine. It is an indispensable part of a gasoline engine. There is a part called a spark plug that plays the role of ignition to burn gasoline, and a high voltage is indispensable to operate this spark plug. Therefore, the ignition coil plays a role in generating a high voltage for the spark plug.

Of course, there are lots of consequences, both economical and mechanical, that you face I you fail to replace a defective ignition. If your vehicle runs on faulty ignition coils, you will see signs such as lack of power and poor engine running. Besides, you will also experience an extended period of engine misfiring, plus damage to catalytic converters. 

You may also have your oxygen sensor in a bad state while the gas mileage reduces drastically. The latter consequence is often due to unused fuel that finds its way back to the exhaust system. all of this simply tells you that the ignition coil of a car is as critical to its functioning as any other part.

How Does a Car Ignition System work?

As we’ve noted earlier, if you need a powerful spark in your vehicle, the ignition coil pack must be hale and hearty, healthy, and active. The coil pack is the guy responsible for building up fire and energy required to generate a very high voltage of a range of 50,000 to 75,000 volts. As an electromagnetic component, the coil taps low-tension voltage from the car’s 12-v battery and generates high-tension voltage enough to spark your vehicle into life. 

The coil pack sends the voltage generated into the spark plug thus igniting the air-fuel mixture ratio in the internal combustion chambers of your car’s engine. Here, the coil reaches the spark plug, releases the high-tension current into it before jumping onto the earth via some points. This will ensure that enough fuel-air explosions take place in the cylinder.

Your coil can work with or without a distributor. The coil often transfers the sparkplugs through the distributor cap. The high-tension current flows from each part of the cap down to the plug before reaching the plug caps. The coil distributes current from the battery to its primary windings before reaching the earth.

What is the life replacement time of an ignition coil?

The guideline for the life and replacement time of the ignition coil is mileage 100,000 km. The ignition coil has a lifespan similar to other automobile parts, and it varies depending on the vehicle type and usage conditions, but the standard is the mileage of 100,000 km.

The fact that the mileage is long means that the engine is also used, so the ignition coil, which is the main part, works in tandem. When the mileage is around 100,000 km, deterioration symptoms are likely to appear in the parts around the engine. 

The maintenance shop is overwhelmingly recommended for inspection and replacement. You can inspect or replace it yourself, but it is safe to ask a nearby dealer or mechanic. This is because asking a dealer or a mechanic may cost you more wages, but it will be completely fixed without any hassle.

Causes of a Defective Ignition Coil

The causes of ignition coil problems are not necessarily the coils themselves. There is a range of underlying issues that cause the ignition coil to fail. We have issues relating to engine misfiring, leaking valve covers, spark plug gapping, or moisture intrusion.

1. Spark plug gapping

Your car ignition coil can become defective due to an excessively worn gap in the spark plug. This will hurt the proper functioning of the ignition system, causing it to overwork. If there is too much gap in the spark plug, it will require the coil to generate more voltage with which the ignition system will bridge the gap. 

This may also create some spark in the cylinder. The internal system of the coil will be stressed and will cause the ECU to fail. However, the coil will have no power any longer to create the needed spark, resulting in the inactiveness of the cylinder.

What to Do: You must fix the problem of a gap in the spark plug. Plug the gap to allow the coil to generate the needed voltage to bring about a spark.

2. Moisture intrusion

This is another major issue responsible for your car’s ignition coil damage. Moisture can result from an oil leak that often comes from a defective EGR valve lid gasket. If there is a leak in the tube system it will cause moisture to spread to the spark plug and ignition coil. The result is a possible failure of the coil. 

What to do: To fix this, look for the cause of the leak and fix it to avoid recurrence.

3. Leaking valve covers

The ignition coil is often mounted on a channel which is a major component of the valve cover. This may experience some leaks, causing the coil to damage. If the seal sitting between the valve lid and tube fails to work, the oil leak will be the result. 

What to Do: You will need to go to the manufacturer’s manual. Some manufacturers provide marine-grade grease or sell ignition coil that comes with pre-applied lubricant. This will provide a better seal between the cover and the spark plug terminal. This ill avert the intrusion of moisture that often prevents the coil from producing a spark or transferring needed voltage.  

Frequently Asked Questions

Q: Must ignition coil be Hot?

It is important to note that your ignition coil will be warm when your vehicle has been put on, or you have driven certain miles. You should also monitor the ignition coil’s temperature, especially when it is burning or excessively hot. In a recent vehicle, check the voltage supply to the coil terminal with the engine cranking, and your vehicle engine must be working.

Q: How can I tell if I should pay attention to the ignition coil? 

There is a wide range of ways you can tell that your ignition is failing. As we have highlighted above, there are things you must watch out for. The three signs here, more than any other, are the prominently associated with and common to the ignition coil problem. Thus, if your vehicle exhibits any of the following symptoms, the first suspect is the ignition coil: 

  1. Difficult starting
  2. The exhaust shooting 
  3. Higher fuel consumption.

Then it is time to pay keen attention to the ignition coil of your vehicle. 

Q: What are the benefits of replacing the ignition coil? 

You cannot exhaust the benefits of replacing a bad ignition coil. Apart from resolving some of the signs we have identified as symptomatic of a failed ignition system, the ignition coil also delivers a lot of goodies to your vehicle. Typically, if you change your faulty ignition coil, three things happen that complement the diagnosis of other issues. After replacing your car’s ignition coil, the following happens:

  1. Improves fuel economy
  2. You can run comfortably
  3. Stable idling

Q: How do you test an ignition coil?

To test the ignition coil of your vehicle, connect a multimeter to your coil pin. Also, link the high output pin to the spark plug of your vehicle. It is common to read between 5,000 to 90,000 ohms. For clarity, visit the nearest mechanic shop.

Final Thoughts

It will always be useful for you to know how to choose the right ignition coil. First, this device crashes quite often. Many motorists confuse coil defects with spark plug defects or high voltage wires. 

You should bear in mind that you can replace one ignition coil. Usually, one pack of an ignition coil serves two cylinders. You may choose to replace one given that one faulty ignition coil pack does not affect the functioning of the other. 

Secondly, understanding the specifics of coil production and their work will help you identify fake and correctly select adjacent nodes, such as the listed candles and wires. 

Ignition coils usually don’t cost much money, but if you have a new car with an individual ignition system, the replacement will cost quite a penny. In case of an exchange, we recommend that you take coils from renowned mechanic shops. 

Also, remember that only a service technician will be able to diagnose the ignition system fully. As you know, an engine needs two conditions: an explosive mixture and a spark.