10 Signs Of An Overheating Ignition Coil

In this article, we present to you 10 signs of an overheating ignition coil in a vehicle.

Ignition coils play a very important role in ensuring that you can use your car as at when due. It works just like a step-up transformer, it helps to convert the car battery’s low voltage (12V) to a high voltage (20KV-40KV); high enough to create a spark, ignite the fuel, and kick start the engine.

Ignition coils and spark plugs are like two peas in a pod. Each spark plug has its ignition coil connected to it using a wire or by carefully resting the ignition coil on it without the use of wires.

While the ignition coils create the electric spark, the spark plugs act as the receiver by creating an avenue for fuel ignition.

Ignition coils are heavy-duty tools that can create about 20,000 volts or more of electricity in spark plugs. This is why it is better to have your engine fortified with strong ignition coils.

Various factors could cause overheating of ignition coils with signs of an overheating ignition coil visibly seen. These symptoms can be seen to be largely related to poor vehicle maintenance.

It is necessary, not just to consider the coils alone, but also to assess the components attached to the coils as they could be the contributing factors. For example, the spark plugs which are directly attached to ignition coils could be faulty or the space in between them too wide.

This could be due to the build-up of gunk on the plugs. Ultimately, it would have a negative impact on the ignition coils, thereby causing overheating.

Ageing has also been proven to adversely affect ignition coils, thus, leading to overheating. This is probably the case with many other engine parts. If your ignition coils have served you for years without replacement, then it is better to have them replaced before an unwarranted situation forces you to do so.

Most car owners would not realize the effects of overheating ignition coils until it begin to manifest on the vehicle.

It would probably take a day of sprinting to the bus station to catch the last bus to the office or an unpleasant surprise visit to the mechanic’s workshop to finally pay close attention to indicators and tell-tale signs.

10 Signs Of An Overheating Ignition Coil

Let’s take a quick look at the various signs we are likely to observe when the ignition coils are overheating.

Smoky emissions

This situation is commonly referred to as ‘backfiring.’

It is characterized by the emission of black smoke from the exhaust pipe. This occurs as a result of the presence of unused fuel in the combustion pipe which attempts to leave via the exhaust.

It usually happens in the early stages of ignition coil failure before other signs become evident. Therefore, if promptly corrected, a much graver situation could be averted.

Noisy starts

Engine misfires are also a common indication of a failed ignition system.

Attempting to accelerate when the ignition coils are overheating would seem like an impossible task. That is not all.

Engine starts are usually a noisy session with coughing and sputtering noises coming from the engine while attempting to make vibrating sounds.

Poor fuel economy

Ignition coil problems could also result in poor fuel economy for your car.

This means that your car will start to burn fuel faster and also cover fewer distances than it used to cover, even with a full tank.

Studies have also shown that faulty spark plugs contribute to poor fuel economy. Thus, if you notice that your vehicle’s mileage has considerably reduced, there could be a problem with your ignition coils.

Weak accelerating power

Now, this is one of the obvious pointers that suggest an ignition coil problem.

If you notice your car accelerating with difficulty or taking moments to change to a higher speed, then you need to get the ignition coil checked.

It is usually coupled with jerky starts and rough idling.

Vehicle stalling

Should we liken this to the calm before the storm?

If you happen to experience a sudden pause in your movement while driving that is usually preceded by a series of stalling movements, then, the coils are faulty.

This is as a result of the faulty coils causing an irregular spark in the spark plugs. If this happens, there is no hope of the vehicle restarting successfully.

Overheating engine

An overheating engine shouldn’t come as much of a surprise at all. It is one of the first effects an overheating ignition coil can have on  a car engine—raising its temperature and subsequently resulting to the engine getting overheated.

An overheating coil would not produce enough voltage to create a spark and ignite the engine but instead, cause overheating and other engine-related problems.

Check engine indicator light

This is the first, if not one of the most certain signs of an overheating ignition coil. If the check engine indicator light is turned on, then there is bound to be a problem, although you would not be able to pinpoint it.

This is because the check engine indicator light being turned on could mean a lot of engine-related problems.

Therefore, you need to be on the lookout for other signs. If you seem to notice any of the other as discussed in this article, the problem will most likely be failed ignition coils.

Hard starting

This is quite expected, especially in cars that make use of a single ignition coil. A fault in the coil affects the engine badly and subjects it to sparkless starts.

This makes it difficult for fuel ignition to take place and as a result causing difficult starts.

In most cases, even if you are able to start the engine, the success is usually short-lived as the engine ends up going off again almost immediately as it starts.

Faulty spark plugs

This is like stating the obvious. The ignition coils and spark plugs are closely related in both effect and functionality.

It is only natural that the problem encountered by one rubs off on the other.

Since both the coils and plugs are interdependent, if the spark plugs are faulty, it could cause the coils to overheat and vice versa.

Oil leakage

When you wake up to find oily stains on the ground right where your car is parked, it could mean a couple of things; one of which is a faulty ignition plug.

It is important to note that ignition coils are submerged in oil. Thus, the oil leak could be as a result of the overheated coil whose housing must have been cracked from the excess heat.

How to Avoid a Bad Ignition Coil

Perform regular maintenance

Cars need regular maintenance to function well. When taking in your car for maintenance, don’t ignore the manufacturer’s instructions on how to go about it. Ensure your mechanic goes beyond just changing the engine oil to looking at other components such as the ignition coil, spark plugs, etc. to see if they’re in good condition.

Do regular spark plugs check

Apart from faulty spark plugs causing an excessive drain on the ignition coil, they can also cause a poor fuel economy. Once you have faulty spark plugs in place, they negatively affect the ignition coil, making them begin to degrade. Like we’ve said, regular maintenance can take care of these two components that depend largely on each other to function effectively. The moment one goes bad, the other is going to be affected.

Check the oil casing

Checking the oil casing would help you to know if there’s any oil leakage. This is done to ensure the electrical system connection surrounding the coil remains intact.

What to do when faced with an Ignition Coil Problem

First and foremost, it is almost impossible to detect this problem while the vehicle is in its idle stage.

Thus, you are most likely going to discover the problem while driving. The check engine indicator light may be the first sign.

If you happen to notice other signs that suggest an ignition coil problem, look for a safe place to park as it is not advisable to drive with overheating coils, so stop driving immediately. This is because the overheating coils can render the coil insulators weak and also cause them to melt.

The engine may also be overheating as a result of the overheating coils. Hence, you may want to wait a little while and allow the engine to cool down before attempting to open the bonnet. It is also important to note that you should never try to open the bonnet with bare hands.

Now would be the best time to place a call across to your auto mechanic and have the coils replaced. Luckily, ignition coils are sold at relatively cheap prices so this would not be much of a problem.

Bottom Line

Most car problems are engine-related and most engine-related problems have to do with failed ignition.

The major causative factors are faulty spark plugs and faulty ignition coils, whose effects are quite intertwined.

We generally do not pay much attention to the coils and prefer to blame all problems on the battery or fuel gauge.

Unfortunately, overheating ignition coils could cause more harm than expected. However, with the proper maintenance practice, ignition coil problems can be minimized, if not completely avoided.

The signs of an overheating ignition coil could be engine overheating, irregular maintenance, engine misfiring and stalling, poor fuel economy, hard starting, and seeing the check engine light on the dashboard.

You must act fast any time you notice one or more of these signs to prevent damages to more engine parts.

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