2019 Ford F-150 Spark Plug Type & Gap

Quick reference

Why the right plug matters

Choosing the correct spark plugs for your 2019 Ford F-150 is crucial for optimal engine performance, fuel efficiency, and longevity. Spark plugs are a relatively small and inexpensive component, but they play a vital role in igniting the air-fuel mixture in your engine's cylinders. Using the wrong plug can lead to a host of problems, from misfires and reduced power to catalytic converter damage.

The key factors when selecting spark plugs are heat range and electrode material. The "heat range" refers to a spark plug's ability to dissipate heat from the combustion chamber. A plug that's too hot (meaning it dissipates heat slowly) can lead to pre-ignition and engine damage, while a plug that's too cold (dissipates heat too quickly) can cause fouling and misfires. Automakers specify a precise heat range for each engine to ensure proper operation.

Electrode material also plays a significant role in plug life and performance.

• Copper plugs are excellent conductors of electricity and heat, but their soft electrode material wears quickly, requiring more frequent replacement intervals (typically 30,000 miles).
• Platinum plugs use a platinum pad on the center electrode, which is harder than copper and resists wear much better, extending their lifespan to around 100,000 miles. They are often used in engines that originally came with platinum plugs.
• Iridium plugs are the most advanced, featuring an extremely hard and fine iridium tip on the center electrode. This allows for a consistently strong spark over a very long lifespan, typically 60,000 miles or more, often exceeding 100,000 miles in some applications. Many modern engines, especially turbocharged ones like the EcoBoost, specify iridium plugs from the factory.

For the 2019 F-150, the EcoBoost engines (2.7L and 3.5L) typically utilize iridium plugs due to their higher cylinder pressures and temperatures. The naturally aspirated 3.3L and 5.0L engines often use platinum plugs, offering a good balance of performance and longevity.

How to gap a spark plug

The gap between the center and ground electrodes of a spark plug is meticulously engineered by the manufacturer to provide the strongest spark. Even if a plug claims to be "pre-gapped," it's always wise to double-check and adjust if necessary, as shipping and handling can sometimes alter the gap.

To gap a spark plug, you'll need a spark plug gapping tool, which can be a coin-style gauge or a wire-type gauge. For modern fine-wire iridium or platinum plugs, a wire-type gauge is preferred to avoid damaging the delicate electrode tip. Insert the correct size wire into the gap. If it's too tight, gently pry the ground electrode back with the tool. If it's too wide, carefully tap the ground electrode on a hard, non-abrasive surface (like a wooden block) to close the gap slightly.

Important: Never attempt to bend the center electrode, especially on iridium or platinum plugs, as this can easily damage the delicate tip.

Replacement procedure tips

The 2019 Ford F-150 engines all utilize a coil-on-plug (COP) ignition system. This means each spark plug has its own individual ignition coil mounted directly on top of it, eliminating the need for spark plug wires.

Here are some tips for replacing spark plugs on your F-150:

1. Preparation: Allow the engine to cool completely before starting. Working on a hot engine can damage components and cause burns. Disconnect the negative battery terminal to prevent accidental electrical shorts. Gather all necessary tools, including a spark plug socket with a rubber insert to protect the plug, a ratchet, extensions, and a torque wrench.
2. Coil-on-Plug Removal: Carefully disconnect the electrical connector from each coil pack. There's usually a small tab that needs to be pressed or pulled to release it. Then, gently twist and pull upwards on the coil pack to remove it from the spark plug well. If a coil pack is stubborn, a slight rocking motion can help. Avoid pulling on the wiring.
3. Inspect the Old Plugs: Before installing new plugs, take a moment to examine the old ones. Their condition can provide valuable clues about your engine's health. Look for signs of oil fouling, carbon buildup, or extreme wear.
4. Anti-Seize Debate: There's been a long-standing debate about using anti-seize compound on spark plug threads. Ford, like many manufacturers, generally recommends against using anti-seize on modern spark plugs that have nickel-plated shells. The nickel plating provides adequate corrosion resistance, and anti-seize can act as an insulator, altering the torque readings and potentially leading to over-tightening and plug breakage or thread damage.
5. Dielectric Grease: It's good practice to apply a small amount of dielectric grease (silicone grease) to the inside of the spark plug boot (the part of the coil pack that sits directly on the spark plug). This helps to prevent moisture intrusion, ensures a good electrical connection, and makes future removal easier. Avoid getting grease on the actual electrode.
6. Torque Matters: Always use a torque wrench to tighten spark plugs to the manufacturer's specified value. Over-tightening can strip cylinder head threads or crack the spark plug's porcelain insulator. Under-tightening can cause the plug to vibrate loose and lead to misfires or heat transfer issues.

Known issues

Thankfully, the 2019 Ford F-150 engines do not suffer from the widespread spark plug issues that plagued some previous Ford engines, specifically the problematic two-piece spark plugs in the 3-valve 5.4L and 6.8L engines from the mid-2000s, which were notorious for breaking during removal. The spark plugs used in the 2019 F-150 are single-piece designs and do not have this inherent design flaw.

However, proper care during installation, particularly adhering to the correct torque specifications, is still crucial to prevent damage to the spark plugs or cylinder head threads.

Need plugs replaced? Find a shop on Repairius.