The ignition coil is a vital component of your vehicle ignition system that helps convert low battery voltage to the high volts needed to ignite the spark plugs. It practically functions like a transformer. Here, the battery’s low volt, usually 12, flows into the coil, where it is converted into high volts up to 40,000V.
The coil stores this high volt for a while and releases it to the spark plugs. However, several components make up the ignition coil, making it function that way. So in this article, I will walk you through ignition coil parts and their role. But before delving into parts, let’s look at the types of ignition coils.
Ignition coil types
There are various types of ignition coils used in cars. However, which is fitted into your vehicle will depend on your car’s age, engine design, and ignition system. Here are the common ignition coil types used in automobiles.
Can type (canister) ignition coil
This type of ignition coil was common among older and vintage vehicles and now in recent cars but with a switch in design. While the former version of the can-type ignition coil used oil as a coolant and an insulator, newer versions utilize a dry insulation design.
Distributor ignition coil
Distributor ignition coils are found in older vehicles that come with a distributor. After transforming the battery voltage to a higher voltage, it transfers this high voltage to each spark plug via a distributor.
Block ignition coil
This type of ignition coil design looks like a block. The block houses several ignition coils attached to each spark plug with ignition cables. So basically, this ignition coil type transfers high voltage to the spark plugs via ignition cables.
Block ignition coil comes in two models—single or double spark technology. In the single-block ignition coil, the high voltage is transferred by individual ignition cables to only one cylinder.
However, in the double spark technology, the volt is transmitted via the ignition cables to two cylinders simultaneously. While one cylinder is at the power stroke, the other is at the exhaust stroke. However, this results in power loss.
Pencil (coil on plug) ignition coil
This type of ignition coil is found in newer cars with electronic systems and does not require an ignition cable to transfer voltage because the coils are placed directly on the spark plugs. Hence the name—coil on plug ignition coil, a design with numerous advantages over other ignition coil types.
First, this design allows each spark plug to have its own ignition coil controlled by the ECU. Secondly, this design also allows power to be transmitted directly to the spark plugs, which invariably minimizes power loss.
Thirdly, since the coils are installed directly on the spark plugs, they do not take up space in the engine compartment, invariably saving space. The pencil ignition coil comes as a single or double spark coil.
Ignition coil pack systems
The ignition coil pack system is almost like the pencil ignition coil. But here, several pencil ignition coils are housed in a single component called a rail or strip. This single strip is then plugged directly into a bank of several spark plugs, unlike a pencil ignition coil where each ignition coil is connected to only one spark plug.
Ignition coil parts
The ignition parts consist of a primary winding, a secondary winding, and an iron core. And the iron core is surrounded by the primary and secondary windings. Here is their role in the ignition coil.
Primary circuit
An ignition coil primary circuit is made up of thick copper wire consisting of hundreds of turns. Basically, around 200-300 turns separated from one another. When the ignition switch is turned, it is this primary circuit that the battery’s low current first flows through.
Secondary circuit
Unlike the primary circuit, the secondary circuit is made up of thin copper wire but with higher turns running into thousands. Basically, up to 21,000 turns, with each wire in the secondary circuits separated from one another by enamel on wires or coats of oiled paper. It is around this secondary circuit that high voltage is built.
Iron core
The iron core is made with a laminated core and placed at the center of the coil. So it’s basically wrapped by the primary and secondary windings. The energy passed from the secondary winding is stored in the iron core as a magnetic field. Then eventually, it is transferred to the spark plug via an ignition distributor.
Frequently Asked Questions-FAQs
Q: Can you repair an ignition coil?
The ignition coil can be repaired and even refurbished. However, if the repair costs almost equal the cost of replacing with a new unit, replace it instead. Also, replace them if they have worked past their service life; it won’t take long before they act up again.
Ignition coil replacement costs around $35-$300, depending on your vehicle and who is doing the job. Always opt for quality coils like the Ngk ignition coil; you better download the ngk ignition coil catalog pdf online to find the right fit for your car. Lastly, while the coil could fail on its own, other interconnected components could be the problem.
Faulty spark plugs or spark plug wires, for example, can cause a rise in the coil’s voltage output that damages the ignition coil’s inner insulation, causing a short. Even faulty ignition coil connectors can disrupt the working of the coil. So while replacing the coil, check and repair/replace other defective components.
Q: How many parts are in the ignition?
Several components make up the ignition system, but the main part of the ignition system is the storage battery, ignition key, ignition coil, spark plugs, and distributor. While the battery provides a low electric current of 12 volts, the switching on of the ignition key allows battery voltage to enter the ignition coil.
The ignition coil converts this low current to high voltage and sends it to the distributors, eventually transferring it to the spark plugs. Though in newer cars, there is no distributor to do this. Instead, the ignition coil sends it directly to the spark with the prompting of the ECU.
Q: Is there a difference in ignition coils?
Yes, there are differences in the ignition coil. There are OEM ignition coils built with quality materials by high-end manufacturers—the same people who make the original equipment parts in your vehicle. These coils are reliable, last longer, and often come with a warranty.
Cheap ignition coils, however, are made of inferior materials by third-party firms.
They are usually inexpensive but not reliable or durable, and this is because they are made of inferior materials. Ignition coils also come in various sizes, and which you use will depend on the number of cylinders. There are coils with an internal resistance of 3.0 ohms, 1.5 ohms, 0.6 ohms, etc.
The lower the resistance, the higher the current produced. In terms of design, while some ignition coil uses breaker points to convert to high current, others use electronic devices to do this, which invariably results in better performance, production of higher voltage for the spark plugs, and better engine control.
Q: What are the 2 types of ignition systems?
In this space, you will see several types of ignition systems which are indeed used in automobiles. However, when we talk of the ignition system types, it means how it transfers power to the spark plugs to ignite the air-fuel mixture in the cylinders. And if we are to go by this, we have just two—distributor and distributor-less ignition systems.
While the distributor system works with a distributor, the distributor less system
works with the engine’s computer. Here is a better explanation. In a distributor ignition system, the ignition coil is not connected directly to the spark plug. So the ignition coil relies on a distributor to send the high voltage to the spark plugs. Distributors are found in old vehicles.
However, in a distributor-less ignition system, the ignition coils are connected to the spark plugs directly. So the ignition coil sends power directly to the spark plugs when triggered by the ECU. Distributorless ignition systems are found in recent vehicles with electronic systems.
Q: What are the 5 ignition systems?
Like you see questions here about the five types of ignition systems, you will also see questions about the 4 types of ignition systems. However, in reality, there are only three types of ignition systems based on your vehicle design.
The only thing is they are later sub-categorized. So what are the 3 types of ignition systems? They include a high-energy ignition system, a coil-on-plug ignition system, and a conventional ignition coil system. All three use a distributor or the vehicle’s computer to transfer ignition coil power.
While all three falls under the distributor and distributor-less ignition system, they are further subdivided. For example, the conventional ignition system is further subdivided into magneto and battery ignition systems.
Final Words
The ignition coil parts are all essential in the working of the ignition coil to convert and supply high voltage to the spark plug. The coil consists of three parts—the primary circuit, secondary circuit, and iron core. While the primary winding receives low voltage supplied by the battery, the high voltage is formed around the secondary winding.
The iron core stores this power before releasing it to the spark plugs. If it fails, your engine may fail to start and need replacing the coils. Autozone ignition coils are of good quality, and thankfully, they also sell replacement ignition coil parts in case you’re opting for repairs. Suppose you’re not able to do this job; refer to an expert so you don’t cause more damage.