2017 Ford F-250 Super Duty — Spark Plug Type & Gap

Quick reference

Why the right plug matters

Your 2017 Ford F-250 Super Duty's spark plugs are crucial for optimal engine performance, fuel efficiency, and emissions. Using the correct spark plug type, heat range, and gap specified by Ford is paramount. A spark plug's "heat range" refers to its ability to dissipate heat. A plug that's too hot can lead to pre-ignition and engine damage, while a plug that's too cold can cause fouling.

Modern spark plugs often feature precious metals like iridium and platinum for their electrodes. Iridium and platinum plugs offer superior durability and longevity compared to traditional copper plugs, allowing for extended replacement intervals. While copper is an excellent conductor, it wears down faster, requiring more frequent changes. For your F-250, Ford specifies long-life iridium plugs to ensure consistent performance over many miles.

How to gap a spark plug

Setting the correct spark plug gap is a simple yet critical step. The gap is the distance between the center and ground electrodes. An incorrect gap can lead to misfires, reduced power, and poor fuel economy. For your 2017 F-250, the specified gap for the 6.2L V8 is 0.049-0.053 inches (1.25-1.35 mm).

To gap a spark plug, you'll need a specialized spark plug gap tool, typically a coin-style or wire-type gauge. Gently slide the gauge wire into the gap. If the plug needs adjustment, carefully bend the ground electrode. Always bend the electrode lightly and incrementally to avoid damaging the delicate center electrode or the porcelain insulator. Never use the center electrode as a fulcrum for bending.

Replacement procedure tips (6.2L V8)

Replacing the spark plugs on your 2017 F-250's 6.2L V8 is a straightforward task for those with some mechanical experience. This engine utilizes a coil-on-plug (COP) ignition system, meaning each spark plug has its own individual ignition coil mounted directly above it.

1. Preparation: Ensure the engine is cool. Disconnect the negative battery terminal to prevent accidental electrical issues.
2. Coil-on-Plug Removal: Carefully disconnect the electrical connector from each ignition coil. Then, unbolt and gently pull straight up on the coil to remove it. Be mindful of any clips or securing mechanisms.
3. Spark Plug Removal: Use a spark plug socket with an extension to reach and remove the old spark plugs. Turn counter-clockwise to loosen.
4. Anti-Seize Debate: There's ongoing debate regarding the use of anti-seize on spark plug threads. Ford's official stance for many modern engines is not to use anti-seize, as the spark plugs come with a special coating and anti-seize can alter the torque readings. For the 6.2L V8, it's generally recommended to install them dry. If you choose to use anti-seize, apply a very thin coat and reduce the torque specification by approximately 20%.
5. Dielectric Grease: Apply a small amount of dielectric grease inside the boot of each ignition coil. This helps seal out moisture, prevents corrosion, and makes future removal easier.
6. Installation: Hand-thread the new spark plugs into the cylinder heads to avoid cross-threading. Once hand-tight, use a torque wrench to tighten to the specified 10 lb-ft (14 Nm).
7. Reconnect: Reinstall the ignition coils, ensuring they are properly seated and bolted down. Reconnect the electrical connectors and finally, the negative battery terminal.

Known issues

Fortunately, the 6.2L V8 in the 2017 Ford F-250 Super Duty does not suffer from the notorious spark plug issues that plagued earlier Ford 3-valve modular engines (like the problematic two-piece spark plugs that often broke during removal). The design of the 6.2L V8's spark plug wells and the recommended Motorcraft SP-534 plugs are generally robust and do not present common breakage or seizing issues if replaced at the recommended interval and torqued correctly.

Need plugs replaced? Find a shop on Repairius.