2019 Ford F-250 Super Duty Spark Plug Guide

Quick Reference: 2019 Ford F-250 Spark Plugs

Note: The 6.7L Power Stroke is a diesel engine and does not use spark plugs; it uses glow plugs (Motorcraft ZD-22) to aid in cold starting.

Why the Right Spark Plug Matters

Your 2019 F-250's gasoline engine relies on a precise spark to ignite the air-fuel mixture efficiently. Using the correct spark plug is critical for engine performance, fuel economy, and longevity. Key factors include:

• Heat Range: This refers to the plug's ability to dissipate heat. A plug that is too "hot" can overheat and cause pre-ignition, while a plug that is too "cold" can develop carbon deposits and misfire. The factory-specified plug has the correct heat range for the 6.2L V8 under all operating conditions.
• Electrode Material: The material of the center and ground electrodes determines the plug's durability and performance. The OEM Motorcraft plugs for the 6.2L V8 are a fine-wire platinum design. Aftermarket iridium plugs offer excellent longevity and are a popular upgrade, while traditional copper plugs, though excellent conductors, wear out much faster and are not recommended for this modern coil-on-plug ignition system.

How to Gap a Spark Plug

Even though most modern platinum and iridium plugs come pre-gapped, it's crucial to verify the gap before installation. A small variance can affect engine performance and efficiency.

1. Use the Right Tool: Use a feeler gauge or a dedicated spark plug gapper. Avoid using the old-style coin-gap tools, as they can damage the fragile fine-wire electrode.
2. Measure Carefully: Slide the correct gauge wire between the center and ground electrodes. For the 6.2L V8, this should be between 0.041 and 0.047 inches. The wire should create a slight drag without forcing it.
3. Adjust Gently: If adjustment is needed, gently bend the ground strap (the curved part above the center electrode) using the adjustment slot on your gapping tool. Never pry against the center electrode, as this can snap it off or crack the porcelain insulator.

Replacement Procedure Tips for the 6.2L V8

The F-250's 6.2L engine uses a coil-on-plug (COP) system, meaning each spark plug has its own individual ignition coil. This simplifies the process compared to older distributor systems.

• Coil-on-Plug Removal: Each coil is held down by a single bolt (typically 7mm or 8mm). After removing the bolt, gently twist and pull the coil straight up to release it from the spark plug. The boot can sometimes stick, so a little twisting force is key.
• The Anti-Seize Debate: This is a hot topic. Ford and spark plug manufacturers like NGK often advise against using anti-seize compound on the threads of modern plated plugs (like the Motorcraft SP-526). The plating itself provides anti-seize properties, and adding more lubricant can lead to over-torquing, which can stretch the plug shell and damage the cylinder head. Always follow the manufacturer's recommendation; in this case, install the plugs dry.
• Dielectric Grease: While anti-seize on the threads is not recommended, applying a small amount of dielectric grease to the inside of the ignition coil boot is a great practice. This prevents the boot from sticking to the spark plug's porcelain, makes future removal easier, and helps seal out moisture.

Known Issues

While older Ford modular engines (like the 3-valve 5.4L V8) were infamous for a two-piece spark plug design that could break during removal, this is not an issue on the 2019 F-250's 6.2L V8. This engine uses a conventional, one-piece spark plug design that is much more robust and reliable, eliminating the fear of leaving a broken shell in the cylinder head.

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