A Guide to Spark Plug Replacement for the 2007-2018 Lincoln MKX
Choosing the right spark plugs for your MKX is crucial for performance and avoiding costly repairs.
- Use only high-quality Iridium or Double Platinum spark plugs from brands like Motorcraft, NGK, or Denso for maximum longevity.
- Due to high labor costs from removing the intake manifold, always replace ignition coils and intake gaskets with the spark plugs.
- Owners of 2.7L EcoBoost models should plan for more frequent spark plug changes (every 40-60k miles).
- If you own a 2007-2008 MKX, be aware of TSB 13-4-17, where a bad coil can damage the engine computer (PCM).
Understanding Spark Plugs in Your Lincoln MKX
Spark plugs are a critical maintenance item, but they are not all created equal. For the V6 engines in the 2007-2018 Lincoln MKX, choosing the right type of spark plug is especially important. Because three of the six plugs are difficult to access, using a long-life plug saves you from repeating a labor-intensive job. 🎬 Watch: Full 2007-2018 Lincoln MKX spark plug replacement walkthrough The original equipment (OEM) plugs are typically Motorcraft-branded iridium or platinum types, designed for longevity.
Engine Differences Matter
The 2007-2018 MKX came with three different V6 engines, and their spark plug needs vary:
- 3.5L & 3.7L V6 (2007-2018): These naturally aspirated engines are durable, and the factory-recommended spark plug service interval is up to 100,000 miles. However, the biggest challenge is that the rear three spark plugs are located under the upper intake manifold, making replacement a significant job.
- 2.7L EcoBoost V6 (2016-2018): This twin-turbocharged, direct-injection engine puts much more stress on its ignition system. Because of the higher cylinder pressures, spark plugs wear out faster. The recommended service interval is much shorter, typically every 40,000 to 60,000 miles, to prevent misfires and performance loss. 🎬 See how to change 2.7L EcoBoost plugs with torque specs
Known Issue for 2007-2008 Models
A Technical Service Bulletin (TSB 13-4-17) was issued for some 2007-2008 MKX models with the 3.5L engine. It warns that a failing ignition coil can short out and damage the Powertrain Control Module (PCM), the engine's main computer. If you have one of these model years and experience a misfire (codes P0351-P0356), it is critical to inspect the ignition coils for damage. The TSB procedure involves replacing the PCM, all six ignition coils, and all six spark plugs to correct the condition.
Choosing the Right Aftermarket Spark Plug
While Motorcraft is the OEM part and a safe bet, several aftermarket brands offer excellent quality, often meeting or exceeding OEM specifications. Given the high labor cost for this job, it is not recommended to use basic copper plugs; their short lifespan makes them a poor economic choice. Stick with Iridium or Double Platinum plugs.
Brand Quality Tiers
- Top Tier (OEM-Equivalent): Brands like NGK and Denso are global leaders and often the original manufacturer for many car brands. Their iridium spark plugs are widely considered a top-quality choice for performance and longevity, making them an excellent investment for the MKX.
- Trusted Aftermarket: Bosch, Champion, and Autolite offer a wide range of high-quality double platinum and iridium spark plugs that are a reliable alternative to OEM. They provide a great balance of performance and value.
- Performance: Brands like MSD focus on high-performance applications. While they are a quality option, they may be unnecessary unless your engine is significantly modified.
Pro Tip: Replace More Than Just Plugs
Since replacing the rear spark plugs requires removing the upper intake manifold, it is highly recommended to replace the ignition coils and intake manifold gaskets at the same time. The additional parts cost is small compared to paying for the same labor twice if a coil or gasket fails later. This is especially true for the hard-to-reach rear bank of cylinders.
| Part/Service | Estimated Cost |
|---|---|
| New Aftermarket Spark Plugs (Set of 6) | $35 - $125 |
| Shop Labor | $240 - $450 |
| Total Professional Installation | $285 - $575 |
Frequently Asked Questions
Why is spark plug replacement so expensive for the Lincoln MKX?
The cost is primarily due to labor. All V6 engines in the MKX are mounted transversely (sideways), and the rear three cylinders are positioned against the firewall, underneath the upper intake manifold. Mechanics must remove this large component to access the plugs, which takes several hours.
🎬 Watch this guide on removing the intake manifold for accessCan I use cheaper copper spark plugs?
It is strongly advised not to. While copper plugs are inexpensive, they have a very short service life. The high labor cost to change the plugs on an MKX means you should use long-life iridium or platinum plugs to avoid having to do the job again in 20,000-30,000 miles.
Do I need to gap the new spark plugs?
Most modern iridium and platinum spark plugs come pre-gapped from the factory for their intended application. While it's always a good practice to verify the gap with a feeler gauge, you must be extremely careful not to damage the fine, brittle tip of an iridium plug. Never use a coin-style gapper on iridium or platinum plugs.
Should I replace my ignition coils at the same time?
Yes, it is a very smart decision. Ignition coils sit on top of the spark plugs and are exposed to the same heat and stress. Given that the labor to access the rear coils is the same as for the plugs, replacing them together saves significant money and potential headaches down the road, especially on higher-mileage vehicles.
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Technical Specifications
OEM Part Numbers: SP-411 SP-589 CYFS12F5 SP-594 CYFS-12Y-2
The Lincoln MKX requires V6 engine-specific, tapered seat spark plugs. The 3.5L and 3.7L engines use platinum or iridium plugs with a 100,000-mile service interval. The 2.7L EcoBoost engine requires iridium plugs designed for turbocharged applications with a shorter service interval. Always verify the correct part number for your specific engine and model year.
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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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