An ignition coil boosts your battery’s low voltage into a high-powered spark essential to fire up your engine. But if it acts up, an ignition coil replacement is unavoidable.
Curious how much you’ll need to switch the ignition coil?
Let’s break down the ignition coil replacement cost and learn why it’s important to get it done. We’ll also highlight the key warning signs of a failing coil for quick detection.
This Article Contains:
- How Much Does an Ignition Coil Replacement Cost?
- Is It Worth Replacing the Ignition Coil?
- 8 Signs You Need an Ignition Coil Replacement
- How Long Do Ignition Coils and Coil Packs Last?
- How to Diagnose an Ignition Coil Issue
- How Does a Mechanic Replace an Ignition Coil?
- 3 FAQs on Ignition Coils
How Much Does an Ignition Coil Replacement Cost?
Let’s explore the estimated cost of replacing a bad ignition coil (spark coil) in your car.
A. Range
The average cost to swap out a faulty ignition coil is between $85 and $470. This range covers:
- New ignition coil cost: $35 to $300 per coil
- Labor cost: $50 to $170
Note: Replacing a single ignition coil will take around 30 minutes. But, it can take longer if multiple ignition coils need to be changed, increasing the labor cost.
B. Factors Affecting Cost
A few other aspects that can impact your total cost include:
- Vehicle make and model: Cars like the Honda Civic and Ford Mustang can work with standard coils on the market. However, luxury vehicles like the Mercedes-Benz E350 and BMW X5 need parts specifically designed for their engines, which can increase your ignition coil cost.
- Ignition system type: Older systems, like conventional breaker-point and electric ignition, use a distributor to create sparks. Meanwhile, modern vehicles have distributorless systems, such as coil-on-plug (COP) and waste-spark, where the coil generates the spark. Among these systems, COP coils are the most expensive due to their advanced design and performance benefits.
- Quality of auto parts: You can choose between Original Equipment Manufacturer (OEM) and aftermarket coils. OEM coils are costlier but more durable than aftermarket alternatives.
Is It Worth Replacing the Ignition Coil?
Yes, absolutely!
Driving with a bad ignition coil is not recommended as you may encounter various issues like damaged spark plugs, exhaust system trouble, and eventually poor gas mileage.
A bad spark coil can also lead to engine misfire, allowing unburned fuel to enter the exhaust system. This can damage the catalytic converter and increase your overall repair cost.
So, when you spot an ignition coil problem, it’s best to book an appointment with a local auto repair service or call a mobile mechanic ASAP.
8 Signs You Need an Ignition Coil Replacement
A few telltale symptoms of a faulty ignition coil include:
- An illuminated check engine light
- The engine won’t start
- Loss of power
- The car jerks and vibrates while accelerating
- Rough idling
- Engine backfires
- Strong fuel smell or black-colored emissions from the tailpipe
- Poor fuel economy
How Long Do Ignition Coils and Coil Packs Last?
Ignition coils (typically found in older distributor-based systems) last around 80,000 to 100,000 miles. However, excessive heat and vibrations can break down the insulating material, resulting in an ignition coil issue.
Worn secondary ignition components (spark plugs or wires) can also cause a coil to work harder, significantly reducing its operating life.
Meanwhile, an ignition coil pack (a collection of multiple ignition coils found in modern distributorless systems) can last anywhere from 120,000 to 150,000 miles. You’ll usually only need a coil pack replacement around 5 to 7 years.
However, this is just an estimate, as the lifespan of an ignition coil pack depends on several factors, such as:
- Coil pack quality
- Driving frequency
- Car maintenance schedule
- Air-fuel mixture ratio
- Spark plug gap
How to Diagnose an Ignition Coil Issue
Verifying issues with even a single ignition coil requires technical knowledge and access to specific diagnostic tools. So, if you’re new to car repairs and don’t have the necessary tools, you should let an expert handle the diagnosis.
Here’s what the auto repair mechanic will do:
- Perform a power balance test to check the revolutions per minute (RPM, which measures how fast your car’s engine is running). This can help assess if the coil and the corresponding cylinder are firing correctly.
- Inspect multiple ignition coils and their wires for visible damage, cracks, or corrosion.
- Shift the faulty coil to a different cylinder to check if the engine misfires.
- Look for any carbon buildup or oil deposits on the spark plugs. These can indicate a misfire or incomplete combustion caused by a bad coil.
- Use a compression tester to check the engine cylinders to rule out other issues that may present symptoms similar to a failing ignition coil.
How Does a Mechanic Replace an Ignition Coil?
During the diagnosis, if the mechanic finds even a single coil that’s damaged, they’ll follow these steps to replace it:
- Turn off the engine, remove the key from the ignition, and disconnect the car battery.
- Disconnect the coil’s connectors to swap out the faulty coil.
- Use a wrench or ratchet to disconnect the failing ignition coil and spark plug wires or remove the retaining bolts (in COP systems).
- Detach the old coil and install the new one.
- Reconnect the spark plug wires in distributor-based systems or fix the ignition coil’s retaining bolts in COP systems.
- Reinstall the auto parts removed earlier and switch on the engine to test.
3 FAQs on Ignition Coils
Read on to explore more information about your car’s ignition coils.
1. How Does an Ignition Coil Work?
In the ignition system, a single coil has two windings: primary and secondary. When the ignition switch is turned on, your car’s battery will send a current of 12 volts through the coil’s primary winding, creating a magnetic field.
Then, your car’s Ignition Control Module (ICM) will interrupt this current flow, collapsing the magnetic field.
This collapse induces a high voltage of 20,000 to 50,000 volts in the coil’s second winding. The high voltage is then sent to the spark plugs to burn the air-fuel mixture in the combustion chamber, starting the engine.
2. What Are the Causes of Ignition Coil Failure?
Some potential reasons why your ignition coils fail are:
- Overheating: Worn spark plugs, trouble with the fuel injector, or a lean air-fuel mixture (more air, less fuel) can overheat the ignition coil and wear it out.
- Voltage spikes: Sudden surges in voltage can overload the coil, causing it to malfunction or even burn out.
- Moisture: When water or moisture enters the coil’s casing, it can lead to electrical shorts and the breakdown of internal components.
- Age and wear: Ignition coils naturally weaken as they age. However, extreme temperatures, frequent engine starts, and poor car maintenance can accelerate aging.
3. Should You Replace Spark Plugs Along with Faulty Ignition Coils?
Not always.
You should only replace the spark plugs with the coils if they fail. Some common signs of malfunctioning spark plugs include low fuel efficiency, engine misfires, rough idling, and starting trouble.
As many of these symptoms are similar to those of a bad coil, car owners can struggle to diagnose the exact issue. It’s best to visit a car repair shop or call a mobile mechanic for consultation.
Help Ignition Coils Keep the Spark Alive with AutoNation Mobile Service
Your car’s ignition coil is essential for powering the spark plugs and engine. But once it’s corroded or damaged, only a replacement can help.
Since replacing ignition coils includes checking components like engine cylinders and spark plugs, you should avoid DIY repairs. Instead, call experts from AutoNation Mobile Service to do the job correctly.
We’re a mobile car repair solution that offers easy online bookings and upfront pricing. We also provide a 12-month | 12,000-mile warranty on all services, including a fuel filter, ignition switch, and coil pack replacement.
Contact us to get your ignition coil problem fixed right from your driveway.