2019 Ram 1500 Spark Plug Guide

Spark plug replacement is a core part of keeping your 2019 Ram 1500 running smoothly. Whether you have the dependable 3.6L Pentastar V6 or the powerful 5.7L HEMI V8, using the correct plugs and specifications is crucial for performance, fuel economy, and engine health. This guide from Repairius.com provides all the data and tips you need.

Quick Reference: 2019 Ram 1500 Spark Plug Specs

Note: The 5.7L HEMI V8 uses two spark plugs per cylinder, for a total of 16 plugs.

Why the Right Plug Matters

A spark plug is a small component that plays a massive role. It must deliver a high-voltage spark at precisely the right moment, under immense pressure and temperature. Using the wrong plug can lead to misfires, poor mileage, failed emissions tests, and even severe engine damage.

• Heat Range: This is a plug's ability to dissipate heat. A "hot" plug retains more heat, while a "cold" plug dissipates it faster. The 2019 Ram engines were designed for a specific heat range. Using a plug that is too hot can lead to pre-ignition (detonation), which can damage pistons. A plug that is too cold can accumulate carbon deposits, leading to fouling and misfires.
• Electrode Material: The center and ground electrodes are where the spark happens. The material used dictates the plug's lifespan and performance.
  • Iridium: The 3.6L Pentastar V6 comes from the factory with iridium-tipped spark plugs. Iridium is an extremely hard and durable precious metal, allowing for a very fine center electrode. This design provides a more focused and consistent spark, improved cold starting, and a long service life of 100,000 miles.
  • Nickel/Copper: The 5.7L HEMI V8 uses traditional nickel-alloy (often called "copper") plugs. While excellent conductors, they wear down much faster than iridium or platinum. Chrysler officially recommends a 100,000-mile replacement interval for these plugs, which is unusually long for a standard nickel plug. Many owners and technicians opt to replace them sooner (around 30,000-50,000 miles) or upgrade to a direct-fit iridium plug for more consistent performance over the full 100k interval.

How to Gap a Spark Plug

All plugs for the 2019 Ram 1500 call for a 0.043 in (1.1 mm) gap. While most premium iridium plugs come pre-gapped, it is essential to verify the gap on every single plug before installation. Shipping and handling can easily close the gap.

Use a wire-style or feeler gauge gapping tool. Do not use the "ramp" style coin tools, as they can put pressure on the fragile fine-wire electrode and damage it. If the gap needs adjustment, gently bend the ground strap (the L-shaped electrode) without touching or prying against the center electrode.

Replacement Procedure Tips

The 2019 Ram 1500 uses a modern coil-on-plug ignition system, which simplifies the replacement process compared to older distributor-based systems.

1. Coil-on-Plug Removal: Each spark plug has an ignition coil directly on top of it. After removing the engine cover, unplug the electrical connector and undo the single hold-down bolt for the coil. Gently twist and pull the coil straight up to remove it. The rubber boot can sometimes stick to the spark plug; a gentle twisting motion is key.
2. The Anti-Seize Debate: For decades, technicians applied anti-seize compound to spark plug threads to prevent them from getting stuck. However, modern plugs, like the NGK plugs specified for your Ram, feature a special trivalent plating that has anti-corrosive and anti-seizing properties. NGK and other manufacturers officially recommend NOT using anti-seize with these plated plugs. The lubricant effect can cause you to inadvertently over-torque the plug, which can stretch the threads or break the plug shell.
3. Dielectric Grease: It is highly recommended to apply a small amount of dielectric grease to the inside of the spark plug boot before reinstalling the coil. This grease is non-conductive; it seals the boot, prevents high-voltage leaks, keeps moisture out, and prevents the boot from sticking to the plug's porcelain, making future service much easier. Do not apply it to the electrical terminals themselves.

Known Issues

Unlike some earlier engine generations from other manufacturers (like the infamous Ford 3-valve Triton plugs), the 2019 Ram engines do not have widespread, well-documented issues with spark plug breakage during removal. The plugs are a standard design. As long as the engine is cool and you use a quality spark plug socket with a swivel and extension, the job is straightforward. Always turn the plugs by hand to ensure they are threaded correctly before using a ratchet.

Need plugs replaced? Find a shop on Repairius.