The first thing that may come to mind when your car starts to misbehave is the ignition coil. This is a very small component, but it plays a significant role in getting your engine started. The ignition coil transforms your car’s battery voltage into the power required to get your engine started.
A faulty ignition coil can lead to various issues, such as stalling, misfiring, or failure to start. The good news is that replacing an ignition coil is not usually a very complex job, but it does have a price tag. Understanding the ignition coil replacement cost will help you to prepare and avoid surprises in the future.
The ignition coil replacement cost in the U.S. will vary based on the make and model of your vehicle as well as the labour charges of your local mechanic. On average, you’re probably looking at $150 to $500 for parts and labour, depending on what it might be.
The cost of driving a luxury car that’s turbocharged or a true luxury model can be more expensive than others. One should, in general, get some quotes so as not to overpay. We’ll get into the nitty-gritty of what impacts the cost and how you can save a few bucks on this necessary repair.
What Is an Ignition Coil?
The ignition coil is one of the most important elements in your vehicle’s ignition system. Its major role is to take your car battery’s relatively lower voltage and convert it to a higher voltage to fire up the spark plug within the combustion chamber of an engine. This spark then allows your car to run. Without this conversion, the spark plug wouldn’t have enough power to ignite the mix, and your engine would probably not start.
Modern engines have one coil per cylinder. For example, with a four-cylinder engine, there are four coils, while a V8 engine will have eight. These coils are made to last the entire lifetime of your car, but they wear out just like any other mechanical component.
Bad or malfunctioning ignition coils can cause an engine to misfire, run poorly, and produce excess emissions, so it is important to replace them promptly to ensure optimal operating conditions for your vehicle.
Types of Ignition Coils
Ignition coils come in various designs for various engine configurations and technological developments. These parts are crucially involved in producing the high voltage necessary to light up the air-fuel mixture in your engine. The type of ignition coil your car uses can determine nearly everything from performance to service costs. Let’s see the three most common forms of ignition coils used and how they differ.
Conventional Ignition Coil (Distributor System)
The conventional ignition coils are used in older vehicles and work with a distributor system. These coils produce high voltage, then transmitted to each spark plug in the engine through a distributor cap and rotor. This system utilizes one coil to power several cylinders, making replacing it more straightforward and less expensive than modern systems.
However, on the negative side, the distributor parts wear out over time and must be serviced occasionally. Although it is less common in newer cars, this type of system is a great cost-saver for people who have older vehicles.
Distributorless Ignition System (DIS)
In the 1990s, distributorless ignition systems that did away with the mechanical distributor were developed. Unlike one central coil, the multiple-ignition coils system is often installed in pairs to simultaneously fire two spark plugs at one time – a waste spark system – and is distributorless.
It is much more reliable because it has fewer moving parts and tends not to wear easily. The only negative is that it can have varying costs because multiple coils cost more than an individual unit. This system balances efficiency and cost, making it extremely popular for late 20th-century vehicles.
Coil-on-Plug (COP) System
This is the most advanced and frequently used design in new cars. Each cylinder has its ignition coil on top of the spark plug. Therefore, the need for spark plug wires is eliminated. This direct connection improves energy transfer and reduces potential points of failure, leading to better engine performance and fuel efficiency.
However, since there is one coil for each cylinder, the cost of replacement can add up, especially in vehicles with high-cylinder engines like V6s or V8s. While more expensive, coil-on-plug systems are highly efficient and reliable, making them the standard for most modern cars.
How Does the Ignition Coil Work?
The ignition coil is a little yet a responsible element for your car. It converts a low 12-volt car battery to the tens of thousands of needed volts to initiate the combustion of the air-fuel mixture in an engine.
That’s how such a huge power burst that spark provides will cause a flame. Without a properly working ignition coil, your engine will have trouble running or even fail to start. So, let’s break down how an ignition coil works.
Primary Coil Activation
Two sets of windings for this wire are in an ignition coil- the primary and the secondary. If the battery in your car sends a 12-volt current through the coil, it is bound to be directed into the primary coil. This particular wire winding is designed such that strong magnetic fields result as electric current passes through it.
The primary coil serves more as the foundation for an ignition process as it establishes the magnetic field necessary to facilitate the following process.
Magnetic Field Creation
The electricity flowing through the primary coil creates a strong magnetic field. This magnetic field holds the energy to be used to make the high voltage that is necessary to fire the spark plug. The more powerful and stable this magnetic field is, the more efficient the ignition process will be. This is where the stage is set for low-voltage transformation into a high-energy spark.
Interrupting the Current
The ECM steps in to control the ignition cycle precisely. At the proper time in the engine’s combustion cycle, it cuts off the current running through the primary coil. That sudden cut-off collapses the magnetic field, releasing the stored energy. The timing is very important; if it’s off even by a fraction of a second, it may lead to misfires or bad engine performance.
Voltage Boost in the Secondary Coil
When the magnetic field collapses, it induces a high voltage surge in the secondary coil. This wire winding has far more turns than the primary coil and amplifies the voltage from 12 volts to tens of thousands of volts. That makes the spark plug generate the powerful spark needed for combustion. Without this step, the spark plug could not ignite the air-fuel mixture reliably.
Delivering the High Voltage to the Spark Plug
The high-voltage energy developed in the secondary coil is transmitted through the spark plug. Today, modern coil-on-plug designs mount the coil directly atop the spark plug to reduce energy loss in making the transition. Older designs transmit energy through spark plug wires or a distributor to arrive at the plug. Magic happens in this step—where a spark ignites the compressed air-fuel mixture that creates the controlled explosion of your engine.
ECM Synchronization
During this process, the ECM ensures complete synchronization with the engine’s combustion cycle. The ECM senses the crankshaft and camshaft positions to spark the ignition coil at the correct time. This results in a proper spark for every cylinder at the right time, thus optimizing the performance and efficiency of the engine.
Symptoms of a Failing Ignition Coil
The ignition coil is critical in ensuring your engine runs smoothly, but like any other engine component, it can wear out over time. When an ignition coil fails, symptoms can range from mild inconveniences to severe performance issues. Recognizing these warning signs early is essential, as ignoring them could lead to more costly repairs and damage to other engine parts. Here’s a breakdown of the most common symptoms of a failing ignition coil.
Illumination of the Check Engine Light
One of the earliest signs of a failing ignition coil is the Check Engine Light coming on your dashboard. This warning is often triggered by an engine misfire code detected by the car’s onboard diagnostics system. While the light doesn’t specify the exact issue, a mechanic can use a diagnostic tool to pinpoint the problem. Ignoring this warning could worsen symptoms and potentially more damage to the engine and its components.
Engine Misfires
A misfiring engine is a classic symptom of a faulty ignition coil. When a coil cannot provide enough voltage to the spark plug, the air-fuel mixture in the cylinder fails to ignite properly. This can result in a sputtering engine, noticeable shaking, or even a loud popping sound from the exhaust. Over time, repeated misfires can damage the catalytic converter, leading to costly repairs. Addressing misfires early can save you from a larger headache down the road.
Rough Idling and Poor Acceleration
If you notice your car shaking or vibrating unusually when idling, it could be due to a failing ignition coil. The inconsistent delivery of sparks to the engine can make it struggle to maintain a smooth idle. Similarly, poor acceleration or a lack of power when pressing the gas pedal can indicate that one or more coils are malfunctioning. These symptoms make driving uncomfortable and increase wear on other engine components.
Drop in Fuel Efficiency
A faulty ignition coil can also lead to incomplete combustion of the fuel-air mixture in your engine. This inefficiency forces your engine to burn more fuel to achieve the same level of performance. If you notice you’re making more frequent trips to the gas station, it could be a sign that your ignition coil isn’t delivering the voltage needed for optimal combustion. Over time, this symptom can significantly increase your fuel expenses.
Raw Fuel Smell or Black Smoke from Exhaust
When an ignition coil fails to ignite the fuel properly, unburned fuel can escape into the exhaust system. This often results in a noticeable raw fuel smell around the car or black smoke being emitted from the exhaust pipe. These symptoms indicate inefficient combustion and suggest that the unburned fuel might damage the catalytic converter. Addressing this issue promptly can prevent further complications and ensure your vehicle meets emission standards.
Difficulty Starting the Engine
In severe cases, a failing ignition coil can make it hard to start your engine, especially in colder conditions or after the vehicle has been sitting idle for a while. If multiple coils are malfunctioning, the engine may fail to start entirely. This happens because the ignition system cannot produce the sparks to ignite the fuel-air mixture in all cylinders. If you experience this symptom, it’s crucial to have your ignition system inspected immediately to avoid being stranded.
Potential Damage to Other Components
A failing ignition coil doesn’t just affect itself—it can have a ripple effect on other parts of your engine. For instance, unburned fuel entering the exhaust can cause the catalytic converter to overheat and fail. Spark plugs can also wear out prematurely due to inconsistent voltage delivery. Identifying and replacing a faulty ignition coil early can save you from costly repairs and keep your engine in optimal condition.
How Much Does It Cost to Replace an Ignition Coil?
Replacing an ignition coil will cost between $91.50 and $862, depending on the kind of vehicle, the number of coils that need replacement, and the labour involved. The ignition coil usually ranges between $50 and $600, but labour will add another $50 to $262. Luxury cars or sports variants tend to be priced more because of the intricacies and high-quality materials used in their parts.
Moreover, the location of the ignition coils can influence the labour time and charge considerably. Below, we provide a breakdown of estimated ignition replacement costs of some of the most popular car brands in U.S. to give you a better idea of what to expect.
Toyota
Replacing an ignition coil in a Toyota typically costs between $150 and $400, based on the model. The ignition coil itself will cost $50 to $200, while labor will be $50 to $150. Models such as the Toyota Camry and Toyota Corolla tend to have moderate repair costs compared to SUVs like the Toyota 4runner. The location of the ignition coils can affect labor costs, especially in hybrid models.
Fixing ignition coil problems early can avoid bigger costs, whether it’s for a Camry or similar to the Nissan Altima ignition coil replacement cost.
Honda
Honda cars are also very affordable when it comes to such repairs. Ignition coil replacement for this automaker can cost between $120 and $400. For example, Honda Odyssey ignition coil replacement cost ranges from $50 to $200, plus labor at $70 to $200. The same price range stands for brand’s other models like Passport and Pilot.  Honda’s ignition coil replacement cost remains relatively low among luxury brands due to easy designs in the engine.
Ford
Replacing an ignition coil in a Ford vehicle, especially popular models like the Ford F150, usually ranges from $150 to $500. The Ford F150 ignition coil replacement cost will depend on how many coils need to be replaced since this truck often uses a coil-on-plug system. Coils run about $60 to $150 each, and labor charges can add $80 to $200. To prevent any issue after replacement, we recommend you choose only the best-quality replacement parts for your vehicle.
Chevrolet
The cost to replace an ignition coil on a typical Chevrolet car is $150 to $450. The replacement is cheaper on smaller models, like the Malibu compared to bigger vehicles, such as the Chevy Uplander. The coil price for a Chevy ranges between $50 and $200, with labor adding $70 to $250 to the total amount. Accessibility to the coils influences labor fees significantly, especially in models with larger engines.
BMW
BMW models have a premium price tag not only for buying but also when it comes to repair. Ignition coil replacement in this automaker’s cars would cost between $300 and $900. For example, luxury sedans such as the BMW 328i have high-performance coils that cost between $100 and $600, and labor fees can go as high as $150 to $300. The BMW 328i ignition coil replacement cost is reflective of the engineering complexity and premium materials used in the vehicle.
What Happens If You Don’t Replace a Faulty Ignition Coil?
Driving with a faulty ignition coil can lead to a cascade of problems. Initially, you’ll notice reduced engine performance, rough idling, and poor fuel efficiency. Over time, the misfiring caused by the bad coil can strain other components, such as the spark plugs and catalytic converter. In severe cases, prolonged misfires can result in engine damage, turning a relatively minor issue into a costly repair.
Failure of the ignition coil can further make your car emit at a higher rate, meaning it might fail an emission test. If your check engine light is on due to an ignition system problem, do not wait; get them checked and sorted out soon to avoid more complications.
Do You Need to Change All Ignition Coils at Once?
Replace just the one that failed, but with your mileage and possibly the age of all coils, others may fail quickly. Thus, it is best to replace all coils simultaneously to avoid the inconvenience and labour costs of multiple shopping trips.
However, replacing all coils can be very costly, especially for vehicles with coil-on-plug systems. If your budget is tight, consider replacing only the bad coil, provided you look for signs of trouble in the remaining coils.
Is It Worth Replacing the Ignition Coil Yourself?
If you have a handy tool kit, you can replace the ignition coil yourself and save a lot of money. Most coil-on-plug systems are pretty accessible. They take basic tools and a little patience. Identify the faulty coil first. You may use a scan tool or swap coils between cylinders to see if the problem follows.
However, some vehicles have coils in hard-to-reach areas, making the job more complicated. In such cases, leaving the repair to a professional might be best if you need more clarification about your abilities or tools. Remember that after replacing the coil, you’ll need to clear the Check Engine Light with a scan tool to ensure the repair was successful.
Related FAQ’s
1. What is the cost of replacing the ignition coil and spark plug?
Replacing an ignition coil will cost between $91.50 and $862. The final cost usually depends on your car’s make, the number of parts that have been replaced, and the labour costs. If one is using high-quality parts or more extensive repairs, this could push the price higher.
If you are replacing spark plugs with ignition coils, it is useful to know how long it takes to replace them. For most vehicles, it takes about 30 minutes to an hour, depending on the engine layout and the accessibility of components.
2. What does it cost to replace BMW ignition coils?
For a BMW, the typical cost of replacing ignition coils ranges from $200 to $500 per coil, depending upon the model and whether you buy OEM parts or aftermarket. Premium vehicles require better quality components, for the most part, raising the price. Labour costs on premium rides like BMW can also be higher.
In Conclusion, replacing an ignition coil is a very common repair that can bring the efficiency and performance of your car back in gear. Costs may vary on a vehicle-by-vehicle and ignition system-by-ignition system basis, but knowing what symptoms point towards which type of ignition coil replacement will save time and money. Learning about the ignition coil and spark plug replacement cost can also help you decide whether to solve the problem yourself or take it to a professional.
Tackling the problem or handing it over to a shop ensures that more expensive complications won’t come knocking eventually. Do not take it lightly if your car is misfiring or has difficulty starting. Inspect your ignition coils and have your vehicle running in perfect shape again.
