2020 Jeep Gladiator Spark Plug Guide

Quick Reference

Why The Right Plug Matters

The spark plugs in your 2020 Jeep Gladiator's engine are small, but they play a huge role in performance and efficiency. Choosing the right plugs is crucial for a smooth-running engine. Here's what you need to know:

• Heat Range: This is the most critical factor. A plug's heat range determines how quickly it dissipates heat from the combustion chamber. A "hot" plug transfers heat slowly, while a "cold" plug transfers it quickly. Using the wrong heat range can lead to pre-ignition (if the plug is too hot) or fouling (if it's too cold). For the Gladiator's Pentastar and EcoDiesel engines, it's essential to stick with the OEM-specified heat range.

• Electrode Material:

  • Iridium: The 2020 Gladiator comes from the factory with iridium spark plugs, and for good reason. Iridium is an extremely hard and durable precious metal, allowing for a very fine center electrode. This creates a more focused spark, leading to better throttle response, improved fuel efficiency, and a longer lifespan – typically around 100,000 miles.
  • Platinum: Platinum plugs are a good mid-range option, offering a longer life than copper plugs but not quite as long as iridium. They are a suitable replacement if iridium plugs are unavailable.
  • Copper: Copper plugs have the largest-diameter electrode and the shortest lifespan. While they are excellent conductors and a good choice for older, lower-voltage ignition systems, they are not recommended for the high-energy ignition systems in modern engines like the Gladiator's.

How to Gap a Spark Plug

Properly gapping your spark plugs is essential for optimal engine performance. The gap is the small space between the center and ground electrodes. Here's how to do it:

1. Use a Feeler Gauge or Gapping Tool: These tools have wires or blades of precise thicknesses. Never use a matchbook or other makeshift tool.
2. Check the Gap: Gently slide the correct-sized wire or blade between the electrodes. It should slide through with a slight drag. If it's too loose or too tight, the gap needs to be adjusted.
3. Adjust the Gap: To widen the gap, gently pry the ground electrode away from the center electrode with your gapping tool. To close the gap, gently tap the ground electrode on a hard surface. Always bend the ground electrode, never the center electrode.

Replacement Procedure Tips

Replacing the spark plugs in your 2020 Jeep Gladiator is a manageable DIY project. Here are some tips specific to the Gladiator's engines:

• Coil-on-Plug Removal: Both the 3.6L Pentastar and 3.0L EcoDiesel engines use a coil-on-plug ignition system. This means each spark plug has its own ignition coil directly on top of it. To access the plugs, you'll need to remove the engine cover and then unbolt and gently twist each coil to pull it off the spark plug.
• The Anti-Seize Debate: There's a lot of debate about whether to use anti-seize on spark plug threads. The short answer is: it depends on the plugs. NGK, the OEM supplier for the Pentastar's plugs, applies a special trivalent plating to their plugs that has anti-seize properties. They specifically recommend not using additional anti-seize, as it can lead to over-torquing. If you use other brands, check their recommendations.
• Dielectric Grease: It's always a good idea to apply a small amount of dielectric grease to the inside of the spark plug boot (the part of the coil that connects to the plug). This helps to seal out moisture and prevent corrosion.

Known Issues

While the 2020 Jeep Gladiator doesn't have any widespread, well-documented issues with its spark plugs, it's worth being aware of some common problems that can affect any vehicle:

• Cracked Porcelain: Over-torquing a spark plug can crack the porcelain insulator. This can cause a misfire and is a good reason to always use a torque wrench.
• Broken Plug Shells: This was a major issue on some older Ford 3-valve engines, but it's not a common problem on the Gladiator. However, if a plug is seized in the cylinder head, it can break during removal. Using the correct tools and techniques can help to prevent this.

Need plugs replaced? Find a shop on Repairius.