Therefore, if this part fails, you could end up with serious problems with your car’s engine.

In this article, we look at the symptoms of a faulty ignition coil and what preventive measures can be taken to ensure a long life for the ignition coil. First, let’s look at the signs to look for:

The most common symptom of a bad ignition coil is a stalling engine along with a check engine light on the dash. You may also notice signs such as a stalled engine, increased fuel consumption and noises coming from the engine.

Because the ignition coil is such an important part of a car’s engine, you can experience many different symptoms when dealing with a bad ignition coil.

Here is a more detailed list of the 6 most common symptoms of a bad ignition coil.

Bad Ignition Coil Symptoms

1. Check engine light

The Check Engine Light will illuminate if there is a problem with the engine. Since the ignition coil has a direct effect on the operation of the engine, the Check Engine Light will begin to flash if there is a problem with the ignition coil.

If you have noticed any of the symptoms listed below and the Check Engine Light, the problem is most likely with the ignition coil.

2. Motor backfire and fail

Engine kickback is noticeable in the early stages of a failed ignition coil. Backfire occurs when there is unburned fuel in the combustion cylinder and it flows through the exhaust pipe.

This will also cause black smoke to come out of the exhaust and a foul smell of gasoline, indicating there may be a problem with the ignition coil. It is recommended to correct this problem immediately to avoid damage to the exhaust system.

3. Stuck motor

If you have a single ignition coil that activates a distributor: Common on older cars, your car may stall while driving. If you drive at normal speed and after a few miles notice that your engine stalls, there is a possibility that the ignition coil is faulty. An engine failure occurs when the ignition coil supplies erratic current to the spark plug. If not repaired right away, your car could come to a complete stop after a few miles.

If you have a newer car with separate ignition coils, your car probably won’t stop while driving if only one ignition coil fails.

4. Poor fuel economy

A faulty ignition coil can cause your car’s engine to misfire and leak fuel from the exhaust without burning it, causing the engine to use more fuel. This significantly increases fuel consumption, indicating that the ignition coil needs service.

A bad ignition coil will not generate enough voltage for the spark plug, causing the engine to work harder than normal.

If your engine is running less than normal on one cylinder due to a faulty ignition coil, your car may sound like a tractor and make a strange engine noise.

6. The car won’t start at all

A damaged or defective ignition coil can prevent the engine from starting completely. If you hear a clicking noise when starting the car, the problem is not with the ignition coil.

However, if there is absolutely no sound, there is a chance that the ignition system has failed, especially if you have an older car with a single coil for all cylinders.

The function of the ignition coils:

The ignition system of the car is designed to generate a high voltage from the car battery and transmit this voltage to the spark plugs. At this voltage, the spark plug will ignite the air-fuel mixture and start the engine.

The ignition coil is basically a high-voltage, low-current transformer that takes the voltage from the car’s 12-volt battery and converts it into 25-30,000 volts, which the spark plug needs for ignition.

Location of the ignition coil

If you have separate ignition coils, the ignition coils are located on top of the spark plugs, usually in the head of the engine.

But if you have a separate ignition coil and distributor, it is often mounted on the body, near the distributor.

Ignition Coil Replacement Cost

The average cost of replacing a single ignition coil 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 a ignition coil is between $30 and $200.

Replacing an ignition coil is usually quite simple and you can easily replace it yourself, but on some car models the job can take an hour or two; therefore you can expect quite high replacement costs in some cases.

Replacing the ignition coil is usually easy, but if you don’t feel comfortable doing it yourself, take it to the mechanic and let the experts do the work.