An ignition coil is a transformer that is used to convert and supply enough current to the spark plug to produce a spark and start the engine. It is a key component of the car’s ignition system, and if it is faulty, your car will not start.
Therefore, if this part fails, you may have serious problems with your car engine.
In this article, we will look at the symptoms of a bad ignition coil and examine what preventive measures could be taken to ensure the ignition coil’s long life. First, let’s take a quick look at the signs to look for.
What Are The Symptoms Of A Bad Ignition Coil?
The most common symptom of a bad ignition coil is a misfiring engine, along with a check engine light on your dashboard. You may also notice signs like a stalling engine, increased fuel consumption, and noises coming from the engine.
Because the ignition coil is such an important part of the car engine, you may experience many different symptoms when it comes to a bad ignition coil.
Here is a more detailed list of the six most common symptoms of a bad ignition coil.
1. Check Engine Light
The check engine light illuminates if there is a problem with the engine. As the ignition coil has a direct effect on the engine’s functioning, the check engine light starts to flash if there is a problem with the coil.
If you have noticed any of the symptoms below and the check engine light, the problem is most likely with the ignition coil.
2. Engine Backfires & Misfires
Engine backfiring is noticed in the early stages of an ignition coil failure. Backfiring occurs when there is an unburned fuel in the combustion cylinder, and it flows through the exhaust pipe.
This also causes black smoke to escape from the exhaust pipe and a bad smell of gasoline, indicating that there may be a problem with the ignition coil. It is recommended that this problem be corrected immediately to avoid damage to the exhaust system.
3. Engine Stalling
If you have a single ignition coil, firing up a distributor – Common in old cars, your car might stall while driving. If you are driving at normal speed and after a few kilometers, you notice that your engine stops, there is a possibility that the ignition coil is defective. An engine stall occurs when the ignition coil delivers irregular current to the spark plug. If it is not repaired immediately, your car may come to a complete stop after a few miles.
If you have a newer car with separate ignition coils, your car will most probably not stall while driving if just one ignition coil has gone bad.
4. Poor Fuel Economy
Due to a defective ignition coil, your car engine might misfire and pour fuel out of the exhaust pipe without burning it, causing the engine to consume more fuel. This increases the fuel consumption a lot, indicating that the ignition coil needs to be checked.
5. Strange Engine Noise
A defective ignition coil does not generate enough voltage for the spark plug, so the engine works harder than usual.
If your engine is running on one cylinder less than usual because of a bad ignition coil, your car might sound like a tractor and make strange engine noise.
6. Car Does Not Start at All
A damaged or faulty ignition coil can prevent the engine from starting completely. If you hear a clicking sound when starting the car, the problem is not with the ignition coil.
However, if there is absolutely no sound, there is a possibility that the ignition system has failed, especially if you have an older car with a single ignition coil for all cylinders.
The Function of the Ignition Coils
The car’s ignition system aims to generate a high voltage from the car battery and transfer this voltage to the spark plugs. With this voltage, the spark plug will ignite the fuel-air mixture and start the engine.
The ignition coil is basically a high voltage, a low current transformer that takes voltage from the car’s 12-volt battery and converts it to 25-30,000 volts, which are needed by the spark plug for ignition.
Ignition Coil Location
If you have separate ignition coils, the ignition coils are located on the top of the spark plugs, usually on the engine’s head.
But if you have one separate ignition coil and a distributor, it is often installed at the car’s body, near the distributor.
Ignition Coil Replacement Cost
The average single ignition coil replacement cost is between $60 and $350, depending on the car model and labor costs. The cost of a single ignition coil is between $30 and $150. The labor cost of an ignition coil is between $30 and $200.
The replacement of an ignition coil is often pretty straightforward, and you can easily replace it yourself, but in some car models, the job can take an hour or two; that’s why you should expect a quite high replacement cost in some cases.
Changing the ignition coil is often easy, but if you don’t feel comfortable doing it yourself, go to the car mechanic and let the experts do the work.
Ignition Coil FAQs
Is it OK to replace just one ignition coil?
Yes, just replacing one ignition coil is perfectly fine. But if the ignition coils were never replaced before, the coils are probably the same age, and there is a risk that the other coils will go bad soon as well. However, ignition coils can be expensive, so most people prefer to just replace the bad ignition coil.
How often should ignition coils be changed?
There is no set schedule for when the ignition coils should be replaced. Ignition coils last quite a long time in most car models and are only replaced when an ignition coil goes bad.
Will a bad ignition coil throw a code?
Yes, a bad ignition coil will throw a code in most cases. You will most likely find a P0300 code along with a P030X code, with the last X replaced with the cylinder number the bad ignition coil is on.
How long do ignition coils last?
You can expect an ignition coil to last around 100,000 miles. However, this depends quite a lot on the car model you drive. In some car models, you never need to replace the coils during the life of the car.
Can you drive with a bad ignition coil?
No, it is not recommended to drive with a bad ignition coil. A bad ignition coil will cause misfires in the cylinder’s combustion chamber, and misfires can cause further problems with your engine or damage your catalytic converter.