A Ford Expedition Owner's Guide to 3.5L EcoBoost Ignition Coils (2015-2021)
Experiencing engine misfires or a rough idle? Your ignition coils might be the culprit.
- A flashing check engine light indicates a severe misfire; pull over immediately to prevent expensive catalytic converter damage.
- For maximum reliability on the 3.5L EcoBoost, OEM Motorcraft coils are strongly recommended by owners over performance or value brands.
- Replacing ignition coils is an easy DIY job that requires an 8mm socket and can be completed in under two hours.
- Always replace spark plugs (Motorcraft or NGK Iridium) at the same time as the coils to ensure longevity and performance.
Is Your Expedition Telling You It Needs New Ignition Coils?
Ignition coils are a common wear item, and when they start to fail on the 3.5L EcoBoost, the signs are usually obvious. Because the engine is sensitive, even one weak coil can cause noticeable problems. 🎬 Watch: How to diagnose a stutter or misfire while passing. Ignoring these symptoms can lead to more expensive repairs down the road, including damage to the catalytic converters.
Flashing Check Engine Light: Stop Driving!
If your check engine light is flashing, it signals a severe engine misfire. Unburned fuel can enter the exhaust and quickly destroy your catalytic converters, a very expensive repair. Pull over safely and have the vehicle towed.
Choosing the Right Aftermarket Ignition Coils
When shopping for new ignition coils, you'll find original equipment (OEM) Motorcraft parts and a wide range of aftermarket brands. While some aftermarket parts offer good value, owner feedback for the 2015-2021 Expedition is very clear: reliability varies greatly between brands.
Brand Quality Tiers for Your Expedition
- Tier 1: OEM & OEM-Equivalent (Highest Reliability)
Motorcraft: This is the original Ford part. Forum discussions and mechanic recommendations consistently point to Motorcraft as the most reliable and trouble-free option for the 3.5L EcoBoost. Many owners who try other brands end up switching back to OEM after premature failures. The most common part numbers are DG-549 for 2015-2017 models and DG-585 or DG-560 for 2018-2021 models.
Denso: Denso is a well-respected OEM supplier for many automakers and is considered a top-tier aftermarket choice. If you are looking for an alternative to Motorcraft that maintains high quality, Denso is a solid option. - Tier 2: Performance Brands (Mixed Results)
Accel: Accel SuperCoils are marketed as a performance upgrade, promising a hotter spark. However, real-world owner reviews are very mixed. While some report improved throttle response, many others experience coil failure in as little as a year, forcing them to reinstall their old OEM coils.
Granatelli: This is another performance-focused brand claiming high voltage output. However, some users have reported immediate misfires after installation, and in at least one documented case, a failed coil was blamed for damaging the vehicle's computer (PCM). Given the risks, this brand should be considered with caution. - Tier 3: Value Brands (Use With Caution)
Hella & Others: While brands like Hella are available from parts retailers, there is little specific feedback from 2015-2021 Expedition owners. Many inexpensive, unbranded coil packs are sold online, but forum users often warn against them, citing high failure rates and the common advice, "you get what you pay for."
A Mechanic's Advice: Replace Plugs and Coils Together
Most mechanics recommend replacing all six spark plugs when you replace the ignition coils. Worn spark plugs can strain the new coils, causing them to fail prematurely. For the EcoBoost engine, owners and mechanics strongly recommend using only Motorcraft or high-quality NGK iridium spark plugs. Also, always check the spark plug gap before installation.
Known Issues, TSBs, and Recalls
There are no active recalls from the National Highway Traffic Safety Administration (NHTSA) for ignition coil failure on the 2015-2021 Ford Expedition. However, Ford did issue an emissions recall (24E13) for some 2018-2021 models. This recall addresses an issue where the onboard computer may falsely trigger a check engine light for the catalytic converter (code P0430). The fix is a software update for the Powertrain Control Module (PCM). While not a coil recall, misfires from bad coils can contribute to catalyst problems, so ensuring this update is done is a good idea.
Cost to Replace Ford Expedition Ignition Coils
The total cost depends on whether you do the job yourself and the brand of coils you choose. You will need to purchase six individual coils.
| Part Type | Estimated Cost (Set of 6) | Notes |
|---|---|---|
| New OEM (Motorcraft) | $390 - $640 | The most recommended and reliable option. Prices vary by retailer. |
| New Aftermarket (Premium) | $300 - $450 | Includes brands like Denso and performance brands like MSD or Accel. |
| New Aftermarket (Value) | $150 - $250 | Lower-cost brands with mixed or unknown reliability. |
| Shop Labor | $100 - $250 | Typically 1-2 hours of labor. |
Frequently Asked Questions (FAQ)
Can I replace just one bad ignition coil?
Yes, you can replace only the failing coil. However, ignition coils tend to fail around the same time. If one has failed, others may soon follow. Many mechanics recommend replacing all six at once for peace of mind, especially if they are original and have high mileage.
Is replacing ignition coils a DIY job?
Yes, this is a very DIY-friendly job for a 2015-2021 Expedition. The coils are easily accessible on top of the engine. The only tool required is an 8mm socket with an extension. The entire job can usually be done in under two hours.
🎬 Watch this step-by-step coil and plug replacement for 2018-2021 models.What are the most common fault codes for a bad coil?
A general misfire code is P0300. Cylinder-specific misfire codes range from P0301 (Cylinder 1) to P0306 (Cylinder 6). You may also see codes P0351 through P0356, which point directly to a problem in the ignition coil's circuit for a specific cylinder.
🎬 See how to fix a specific Cylinder 1 misfire code.Do I need to disconnect the battery?
It is always a recommended safety precaution to disconnect the negative battery terminal before starting any electrical work on your vehicle.
What is dielectric grease and do I need it?
Dielectric grease is a non-conductive silicone grease applied to the inside of the ignition coil boot before installing it on the spark plug. It helps prevent moisture from getting in, protects against voltage leaks, and makes it easier to remove the coil in the future. It is highly recommended for this job.
Helpful Videos
Technical Specifications
OEM Part Numbers: DG-549 BL3Z-12029-C BL3Z-12029-A BL3Z-12029-B DG-585 DG-560
System Type: Coil-on-Plug (COP). Quantity Required: 6. Hold-down Bolt Head Size: 8mm. Hold-down Bolt Torque: 62 in-lb (7 Nm).
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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.
- Ford Expedition:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Is Your Expedition Telling You It Needs New Ignition Coils?
- Flashing Check Engine Light: Stop Driving!
- Choosing the Right Aftermarket Ignition Coils
- Brand Quality Tiers for Your Expedition
- A Mechanic's Advice: Replace Plugs and Coils Together
- Known Issues, TSBs, and Recalls
- Cost to Replace Ford Expedition Ignition Coils
- Frequently Asked Questions (FAQ)
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