The Ultimate Ignition Coils Buying Guide

You Should Know This About Your Car Ignition Coils

Does your car fail to function smoothly and steadily? Is the fuel consumption higher than expected? All this and several other issues can be found if your ignition coils are failing. This critical component provides the spark necessary for igniting the fuel and makes your vehicle run. If you are driving with an ignition coil that has gone bad, then you will be compromising on the fuel efficiency, will have trouble while starting your car and the overall engine performance will decline. Use this guide to help you find the best ignition coils for your vehicle. 

What Is The Function Of The Ignition Coil?

An ignition coil, also known as the spark coil is an important component of the ignition system. The primary job of the ignition coil is to ignite the air-fuel mixture in the engine for the combustion to take place. For this, thousands of volts are needed, but the car battery has only 12 volts. So the ignition coil transforms the low voltage into thousands of volts that is needed so that the vehicle can start and run. In older ignition systems, only one coil was used. However, the recent models use one coil for each cylinder.

What Are The Types Of Ignition System?

Distributor Ignition System


This is one of the oldest types of the ignition system and is also known as the conventional breaker point ignition system. Due to the mechanical nature of this ignition system, and the duration of their operation, diagnosis and repair and relatively simple. However, they do have several moving parts, increasing the risk for failures. Furthermore, damage to these systems can negatively impact the maximum spark energy throughout the engine life, causing repeated misfires and increased emissions. 

High Energy (Electronic) Ignition System


In order to overcome the drawbacks of the distributor ignition system, electronic ignition systems were introduced by the auto manufacturers. This system also replaces the breaker point and condenser in an ignition coil with a transistorised switch which also helps to produce a high voltage current by activating the ignition coil. This could be advantageous because the use of an electronic switch means there are less moving parts than the conventional type while at the same time they are easy to diagnose and repair. This system can also provide a reliable, high voltage spark throughout the engine’s life, which ensures less misfires. So this system was introduced to replace the conventional types, they still use a distributor cap and rotor to distribute current to the spark plugs. Usage of distributor means they will wear out eventually, which needs replacement and additional repair cost. The ignition timing cannot be monitored as accurately as with modern technologies, which will result in lethargic acceleration and poor fuel efficiency. 

Distributorless (Waste Spark) Ignition System


Just as the name implies, this system eliminates the distributor completely. Instead of two, three, or more ignition coils were packed together. A magnetic triggering device can determine the engine speed and the crankshaft position. This triggering device sends a signal to the ECM which sends energy to the coil. This system was beneficial as they were designed to generate high voltage. Added to this, the ignition timing can be managed accurately for lower emissions. Also, lesser moving parts means lower maintenance costs but diagnosing any faults can become harder and more expensive than traditional systems. This system will also need double platinum plugs because of reverse firing.

Coil-on Plug (Direct) Ignition System


Of all the ignition systems, this is the sophisticated one, as it directly places an ignition coil on each spark plug and is best suited for modern engines. Depending on the input from various sensors, the Engine Control Unit handles the ignition timing. High voltage spark plug wires are completely eliminated as each spark plug has its own coil. Direct ignition systems are highly beneficial for several reasons. As there are no moving parts, the maintenance cost will be low. It can be difficult to diagnose and repairs can be expensive when compared with a traditional system. But as the maintenance cost is low, the repairs will be less frequent. The ignition timing can be controlled and high voltage can be generated with the help of ECU just like in the distributorless ignition system. 

What Are The Things I Should Consider When Buying Ignition Coils?

Buying an ignition coil for your vehicle can sometimes be a confusing task. As there are countless options available for several makes and models, you may be confused as to what you should look out for when buying ignition coils. To help prevent that confusion, here are a few things that you should consider before you get one. 

A. Compatibility

This is one of the biggest factors to consider when choosing ignition coils. There are different models available in the market today and each one is designed to fit certain car engines. So, before you make any purchase, ensure that the chosen ignition coil goes well with your vehicle. 

B. Number Of Coils

Each coil is connected to its own spark plug in modern cars. The vehicle you use can help you understand how many coils are needed. For instance, if you have a V8 engine, then you will have to replace 8 ignition coils if they start failing. So, it's always best to determine the number of coils your vehicle requires, so that you can get the exact number or more.

C. Accessories

Accessories can always make your deals sweeter. They are always an added plus, that can help in the overall functioning of the coil. But before you buy them, compare the prices. This can help you know if it is a good deal.

D. Brands

There are some well-known brands available in the market and one such example is Bosch as they manufacture high-performance ignition coils. Ignition coils from well-known brands are usually of high quality and can be the best replacements you can get so far. So it is important to know these trusted brands as you can narrow down your options. 

E. Warranty

One of the best features every person has to look out for is the warranty of the product. Anything can happen after an investment. While there are ignition coils with a 1-year warranty, there are others with a lifetime warranty. It is always best to invest in a product that has a lifetime warranty because it ensures that the investment is effectively secured till the day it completes serving its purpose and needs replacement.

Which Top-brand Ignition Coil Should I Choose?

Delphi Ignition Coil

The electrical energy needed for igniting the air-fuel mixture in the combustion chamber of the engine is given by Delphi Ignition Coils. They are designed to satisfy a broad range of constantly changing combustion tuning specifications. Delphi Ignition Coils are also engineered in order for producers to deliver the best engine efficiency, exhaust emissions, and fuel economy targets under all operating conditions and the maximum speed range.

Part Numbers: GN10328, GN10638, GN10571, and more. 


  • Enhanced dwell accuracy reduces module and coil temperatures for improved confidence.
  • Lamination noise reduction content reduces audible coil noise
  • The primary connector has been modified to make assembly more convenient compared with the prototypes with one connector per coil
  • Lower primary inductance gives a fast output
  • Early and reliable electronic functioning leads to fuel-saving and quicker run-up
  • Greater fuel energy source ensures safer combustion to assist manufacturers in compliance with the criteria for on-board diagnostics (OBD II).
  • Composite iron coils deliver programmable strength
  • Coil per dwell cylinder overlaps electronics boost high speed and heat dissipation in contrast with other traditional techniques.
  • The coil per cylinder ramp and fire electronics decreases power dissipation and increases performance

For more information and a detailed product line, visit Delphi Ignition Coil Section.

Bosch Ignition Coil

All Bosch ignition coils are engineered to meet or exceed the OE criteria and are known for their durability and efficiency in the industry. Ignition coils from Bosch transform low-voltage to high ignition system voltage, generating an electric spark sent to ignite the fuel in the spark plugs.

Part Number: 0221504470, 0221604115, 0221504800, and more. 


  • Meets or exceeds OEM specification
  • Excellent stability and protection against corrosion
  • Direct fit application
  • Reduced automotive fuel consumption and exhaust emissions
  • Ensure smooth engine output with stable voltage
  • Backed by Bosch Limited Lifetime Warranty

For more information and a detailed product line, visit Bosch Ignition Coil Section. 

Bluestreak Ignition Coil

Part Number: DR39, FD478, FD509, and more.


  • Built for spark energy output, impedance, and sustainability and tested to equal or surpass OE
  • Checked at 7200 RPM under intense engine output
  • Advanced thermoplastic coil connector guarantees adequate contact and resists hot- and thermal cycling fractures
  • High-temp boot prevents high-voltage leaks, while stainless-steel spring provides a proper connection with spark plug
  • High-impact housing material assures superior epoxy bonding under all working environments for longer lives
  • Internal permanent magnet core of neodymium, surrounded by magnetically oriented steel, allows high-voltage output to be maximized at any speed.
  • Main (22-gauge) and secondary 44-gauge copper wire guarantee high voltage availability for high output while improved bobbins avoid voltage flickering for long life.
  • High-grade insulation copper wires guarantee thermal tolerance and avoid a high-voltage loss
  • Optimally developed wire delivery by rigorous research guarantees superior operating parameters and long life.
  • Isolators made from high-voltage thermoplastics avoid premature coil failure.

Standard and Intermotor: 

  • In order to increase the reliability and to improve the resistance to internal shorts and Dielectric breakups, our ignition bobbins use 100 % pure copper windings
  • Our premium ignition coils consist of a special mixed formula for optimal efficiency and the longest life.
  • A complete E-Lam silicon steel core and a sturdy high tension brass terminal guard against corrosion. Our ignition coils are optimized for optimum voltage.
  • Main and secondary windings have enamel magnetic wire with the best aftermarket temperature rating
  • Our ignition coils are built to a high degree of consistency as a manufacturer with engineering and design skills
  • As a global supplier of original ignition systems, we retain full control of the quality from the component to the final product during the development process.


  • High-performance laminations maximize the build-up of the magnetic field to achieve high energy consumption and high performance. 
  • The Standard® T-Series DIS ignition coils are made of steel or aluminum as shown by the OE

For more information and a detailed product line, visit Bluestreak Ignition Coil Section. 

Denso Ignition Coil

Part Number: 673-6004, 673-7000, 673-6200, and more. 


  • Enhanced coil performance eliminates the need for high voltage generation
  • Circuit driving is integrated into the coil top
  • A cylindrical ignition coil prohibits the use of ignition wires.

For more information and a detailed product line, visit Denso Ignition Coil Section. 

Why Do My Ignition Coils Fail?

While the ignition coils are built to last, their increasing demands will lead to failure. Their primary reasons are:

A. Damaged Spark Plugs/wires

A weak spark plug or overly reactive spark plug wire allows the output voltage of the coil to raise - the coil can destroy the internal insulation of the spark plugs if the voltage exceeds a safe threshold, causing both the spark plug and the coil to fail. This can cause poor performance, leading to ignition malfunctions under load or poor starting.

B. Excessive Spark Plug Gap

The gap between the two electrodes will wear as spark plugs wear, showing that the coil now has to produce higher voltage to bridge it. The added pressure on the coil will lead to an overload of voltage which will cause overheating.

C. Damage Because Of Vibration

Constant wear and tear from the engine vibration can weaken the windings and insulation of the ignition coil. This can cause the secondary windings to break. Likewise, the electrical attachment can be loosened at the spark plug which makes the coil work overtime to ignite the spark plug.

D. Overheating

Ignition coils are often subjected to higher engine temperatures because of their location. This will decrease the coil's ability to conduct electricity, which influences both its efficiency and its reliability.

E. Varying Resistance

A short or low winding resistance of the coil can increase the electrical flow of the coil causing damage to the whole ignition system. Resistance variations can also create a weak spark that does not start the car. 

F. Excessive moisture

This can most likely happen because of oil leakage from the failed valve cover gasket. The oil that is built up can damage both the ignition coil and the spark plug. For eg, water may also enter the system from the A/C condensation. In both cases, it is necessary to address the root cause, so that you can avoid repeated failures. To prevent similar issues in the future, it is necessary to deal with the underlying cause.

What Are The Signs That My Ignition Coil Is Faulty?

The ignition coil is a small engine component, but it has lots of responsibilities. The engine will not start if the ignition coil is faulty. Faulty ignition coils that are not addressed quickly can lead to expensive repairs. Here are a few signs that your ignition coil is faulty.  



One of the very first symptoms of a faulty ignition coil can be backfiring. This likely happens when unused fuel is emitted through the exhaust system. This issue has to be resolved quickly else you will end up with costly exhaust repairs. The major symptoms of exhaust damage are black smoke or gasoline smell.

Poor Fuel Economy

If your ignition coil doesn’t transmit sufficient energy, then it has to burn and use additional fuel. This is the only way you can keep your vehicle going. If your vehicle gets less mileage than it already should, then it is a sign of a faulty ignition coil.

Engine Misfiring


If your engine misfires, then you may be having a problem with the ignition coil. You may also experience vibration, a loss of power, decreased fuel economy, or a rougher ride while driving. A misfiring can most often sound like coughing or sputtering noise which means one of the engine’s cylinders is not firing properly. 

Engine Jerking, Rough idling, Poor Power

Engine performance issues are one of the most common symptoms associated with faulty ignition coils. As ignition coils are part of the ignition system, even a slight issue can cause a spark and lead to performance issues. Faulty coils can cause the vehicle to jerk, experience a rough idle and hesitation while accelerating. You may feel as if you’re missing some power while driving. 

Vehicle Stalling


If your vehicle stalls often, then you will undergo abrupt stops and starts. You may feel frustrated to drive and needless to mention, quite dangerous too. If one or more ignition coil fails, then your vehicle will stall. The faulty coils will send irregular sparks and prevent the engine from running smoothly. 

Check Engine Light On

If the ignition coils are faulty, it will lead to performance issues, specifically misfiring. The check engine light will pick this up and turn it on. Never ignore this. The easiest way to check this is by using a car diagnostic tool. The engine code P0300 to P0312 shows misfires, and P0350 to P0362 is for ignition coil issues

Engine Hard Starting


If you have trouble starting your vehicle, then you may think it's because of the battery. Sometimes, the ignition coils can be the real culprit and this can likely occur if you are using a single coil. A malfunctioned coil can cause the engine to crank without sparks inside the cylinder. 

How Much Will It Cost Me To Replace The Ignition Coil?

The cost of an ignition coil will vary depending on the make and model of the vehicle. The average cost can range between $200 to $400. This includes labor and parts costs. The parts can cost around $165 to $250 whereas the labor cost can range from $75 to $130. So if you can install the ignition coil on your own, then you can save this money. The amount you spend usually depends on whether you are fixing by yourself or taking it to a mechanic. 

Delphi Ignition Coil - Part Number Catalog


Part Numbers

Delphi Ignition Coil

GM10168, GN10119, GN10494,

GN10633, GN10426, GN10560,

GN10316,  GN10114,  GN10370

Bosch Ignition Coil - Part Number Catalog


Part Numbers

Bosch Ignition Coil

0221604700, 0221504048, 02215044650986221058, 0221604010, 0221504029

0221604008, 0986221024, 0221503035

Bluestreak Ignition Coil - Part Number Catalog


Part Numbers

Bluestreak Ignition Coil

UF400, UF411, UF378, FD508, UF667, UF262, UF648, UF622, UF303, UF504, UF341, UF575, UF569, UF413, UF553

Denso Ignition Coil - Part Number Catalog


Part Numbers

Denso Ignition Coil

673-7104, 673-8311, 673-7300, 673-8312, 673-6202, 673-6011, 673-1300, 673-8305, 673-9300, 673-2302


Articles and Guides that are written with the help of mechanics to ensure you have all the knowledge you need to make the correct purchase here at PartsAvatar.

Read all Guides & Articles


The experts suggest that when you experience a difference in the performance of your car’s engine; it is the safest time to change the ignition coils. Normal functionalities and signs include delayed start, misfires, and poor fuel management. All of these may mean that it is time for the replacement of the ignition coil. You can also check if the ignition coils are working by yourself. Refer to this article to learn how to diagnose ignition coils.

It is usually based on the vehicle type, type of ignition coils, and driving conditions. However, ignition coils can last over 1,60,000 km or more.

You can change just the faulty ones if you can locate them correctly. However, experts recommend replacing them all at the same time to avoid future problems.

Yes! Mechanics suggest you replace all the spark plugs even if you are changing just one ignition coil. As ignition coils and spark plugs work closely together, a problem with the coils can cause the plugs to malfunction and fail.

persona image
Mike Morrales
Automotive Product Expert
A super dork when it comes to new automotive tech. Part manufacturers are constantly making revolutionary product updates for their aftermarket line up. However, knowing what changes were made and how they could affect your day to day driving adventures is something our automotive product expert will definitely be chiming in on, stay tuned !.