A Guide to Replacing Ignition Coils on Your 2015-2021 Mazda 6
Keep your Mazda 6 running smoothly by understanding when and how to replace your ignition coils.
- Ignition coil replacement on the 2015-2021 Mazda 6 is a very easy DIY job, requiring only an 8mm socket.
- A flashing check engine light indicates a serious misfire; you should pull over and avoid driving.
- For best results, choose reputable aftermarket brands like NGK or Delphi, as NGK is an OEM supplier for Mazda.
- Consider replacing all four coils and the spark plugs at the same time on high-mileage vehicles for preventative maintenance.
Is Your Mazda 6 Ignition Coil Failing?
Ignition coil failure is a common issue as a car ages. For the 2015-2021 Mazda 6, which uses the Skyactiv-G 2.5L engine, the coils are generally reliable but can fail over time due to heat and vibration. A failing coil can cause noticeable problems that affect your car's performance and drivability.
Key Symptoms of a Bad Ignition Coil:
- Check Engine Light: This is often the first sign. The light will turn on when the car's computer detects a problem, such as a misfire. Common codes include P0300 (random misfire) or P0301-P0304, which point to a specific cylinder. 🎬 See how a failing coil pack causes engine misfires.
- Engine Misfires: The engine may sputter, shake, or hesitate, especially when you accelerate. This happens because one cylinder isn't firing correctly.
- Rough Idle: When stopped, your car might idle roughly or vibrate more than usual. It might even stall.
- Reduced Power and Fuel Economy: With one cylinder not working efficiently, your car will feel less powerful and use more fuel.
- Difficulty Starting: A weak or failed coil can make it harder to start the engine.
Aftermarket Brand Quality Tiers for Mazda 6
| Tier | Brands | Description |
|---|---|---|
| Premium Aftermarket (OEM-Quality) | NGK, Delphi | These brands are often original equipment manufacturers or have a strong reputation for quality and reliability that meets or exceeds OEM standards. NGK is noted as an OEM supplier for many Mazda parts. They are a trusted choice for longevity and performance. |
| Standard Aftermarket | Spectra, Standard Ignition (SMP), Walker Products | These brands offer a good balance of price and quality. They are reliable for daily driving and are a popular choice for owners looking for a dependable part without the premium price tag. |
| Economy | DriveWire, True Tech, Facet, Holstein | Economy brands provide a low-cost option to get your car running again. While they are functional, their lifespan and performance may not match that of higher-tiered brands. Some owners report premature failure with budget-friendly options. |
Known Issues, Recalls, and TSBs
There are no specific recalls for ignition coils on the 2015-2021 Mazda 6. However, Mazda did issue a Technical Service Bulletin (TSB), TSB 01-014/16, for some earlier models in this range. This TSB addressed potential ignition coil failure on vehicles with coils made by a specific supplier (Yumebishi) before March 28, 2016. The issue was related to internal failures caused by large temperature changes, leading to misfires and the check engine light coming on. While this was addressed under warranty for affected vehicles, it's a good indicator that coils on 2015-2016 models may be more prone to failure.
Pro Tip: Replace in Sets?
Ignition coils can be replaced one at a time. However, if one coil fails on a higher-mileage vehicle, the others may not be far behind. To save time and ensure consistent performance, many mechanics recommend replacing all four coils at once, especially if you are already replacing the spark plugs.
DIY Replacement Guide
Replacing the ignition coils on a 2015-2021 Mazda 6 is a straightforward job that most DIYers can handle. 🎬 Watch this step-by-step video guide for replacing your ignition coils. The coils are located directly on top of the engine and are easily accessible.
- Locate the Coils: Remove the plastic engine cover by simply pulling it up. You will see the four ignition coils in a row.
- Disconnect the Connector: Press the tab on the electrical connector and pull it off the coil.
- Remove the Bolt: Use an 8mm socket to remove the single bolt holding the coil in place.
- Remove the Coil: Gently pull the coil straight up to remove it from the spark plug well.
- Install the New Coil: Apply a small amount of dielectric grease to the inside of the new coil's boot to protect it and ensure a good seal. Push the new coil firmly down onto the spark plug until it seats properly.
- Reinstall and Reconnect: Secure the coil with the 8mm bolt (torque to 85 in-lbs or just snug), reconnect the electrical connector, and replace the engine cover. 🎬 Follow this visual walkthrough to ensure a proper installation.
Common Mistake
When replacing coils, it's a great time to inspect or replace your spark plugs. Worn-out spark plugs can put extra strain on new ignition coils, causing them to fail prematurely. The recommended spark plugs for the Mazda 6 are NGK Iridium plugs.
Frequently Asked Questions (FAQ)
Should I use OEM or aftermarket ignition coils?
For the Mazda 6, high-quality aftermarket brands like NGK and Delphi offer performance and reliability that is comparable to OEM parts, often at a lower cost. NGK is a known OEM supplier for Mazda, so their aftermarket parts are a very safe bet. While very cheap, economy-tier coils can be a gamble and may not last as long.
Can I replace only the one bad coil?
Yes, you can replace only the failed coil. To find the bad one, use a code scanner to identify the misfiring cylinder (e.g., P0302 for cylinder 2). You can confirm by swapping the suspected bad coil with a known good one from another cylinder. If the misfire code follows the coil, you've found the culprit. However, for cars with over 100,000 miles, it's often wise to replace all four to prevent future failures.
How much does it cost to replace Mazda 6 ignition coils?
If you do it yourself, you will only pay for the parts. A single aftermarket ignition coil can range from about $40 to over $150 depending on the brand. If you take it to a shop, expect to pay for about 30-60 minutes of labor in addition to the part cost.
What is the OEM part number for the ignition coil?
The most common OEM part number for the 2015-2021 Mazda 6 ignition coil is PE20-18-100A. This part number may have superseded older numbers like PE01-18-100.
Helpful Videos
Technical Specifications
OEM Part Numbers: PE20-18-100A PE20-18-100 PE01-18-100A PE01-18-100 P51B-18-100
Coil-on-plug design, requires one coil per cylinder. Four coils are needed for the 2.5L Skyactiv-G engine.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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