2024 Jeep Gladiator Spark Plug Type, Gap & Torque Specs

As an ASE-certified master technician, I’ve seen firsthand how a simple maintenance task like replacing spark plugs can make or break your vehicle's performance. For the 2024 Jeep Gladiator, you are primarily dealing with the tried-and-true 3.6L Pentastar V6 engine. Whether you're tracking down a misfire or just hitting that 100,000-mile maintenance milestone, having the correct spark plug part numbers, gaps, and torque specs is absolutely critical.

Here is your comprehensive guide to the spark plug specifications for the 2024 Jeep Gladiator.

Quick reference

Note: The 3.0L EcoDiesel V6 was discontinued for the 2024 model year, making the 3.6L V6 the standard powertrain. Diesel engines use glow plugs rather than spark plugs.

Why the right plug matters

Choosing the correct spark plug is more than just making sure the threads fit. Modern engines are highly sensitive to two main factors: heat range and electrode metallurgy.

• Heat Range: The heat range dictates how fast the spark plug pulls heat away from the firing tip into the cylinder head. If you use a plug that runs too hot, you risk pre-ignition and engine knock. If it runs too cold, carbon deposits will build up, leading to misfires. Always stick to the OEM-specified heat range.
• Electrode Metal (Iridium vs Platinum vs Copper): The 2024 Jeep Gladiator uses a coil-on-plug ignition system that outputs high voltage. Factory plugs are double-platinum or iridium. Never downgrade to copper plugs in a modern Pentastar engine. While copper conducts electricity well, it wears out incredibly fast. Iridium plugs, on the other hand, can easily last the recommended 100,000-mile interval without widening the gap through erosion.

How to gap a spark plug

Even if the box says "pre-gapped," a good technician always verifies the gap before installation. A dropped box in transit can close the gap, causing an immediate misfire upon startup.

1. Use the right tool: Do not use a cheap coin-style gapper on modern iridium or platinum plugs. The center electrode is extremely fragile (often only 0.4mm to 0.6mm thick). Instead, use a wire-style feeler gauge.
2. Check the gap: Gently slide the 0.043-inch (1.1 mm) wire gauge between the center and ground electrode. It should slide through with a slight "drag."
3. Adjust if necessary: If the gap is too tight, use the bending tool on the gapper to carefully pry the ground strap away from the center electrode. Never pry against the delicate iridium center tip. Bend it slightly, then re-measure.

Replacement procedure tips

Working on the 3.6L Pentastar V6 in the Gladiator requires a bit more effort than older inline-six Jeeps.

• Upper Intake Manifold Removal: The right bank (passenger side) is easily accessible, but the left bank (driver's side) is buried beneath the upper intake manifold (plenum). You must remove the upper intake manifold to access the remaining three coil-on-plug assemblies. Be sure to buy a new set of upper intake manifold gaskets before starting this job, as reusing the old ones can cause a vacuum leak.
• The Anti-Seize Debate: Most modern OEM and premium aftermarket plugs (like NGK and Denso) feature a specialized trivalent metal plating on the threads. This acts as a release agent. Applying anti-seize to these plated threads is generally discouraged, as the lubricant can cause you to over-torque the plug by up to 20%, potentially stripping the aluminum cylinder head. Install them dry.
• Dielectric Grease: Apply a small dab of dielectric grease inside the boot of each ignition coil before reinstallation. This prevents the rubber from fusing to the ribbed porcelain of the spark plug over the next 100,000 miles, making future removal much easier and preventing moisture intrusion.

Known issues

Unlike some notorious engines in the industry, the 3.6L Pentastar does not suffer from widespread spark plug catastrophes. For context, older Ford 3-valve 5.4L engines were infamous for a two-piece spark plug design where the shell would seize in the head and snap off during removal, requiring a specialized extraction tool. Similarly, some older GM coil setups were hyper-sensitive to aftermarket plugs because they used ionization-sensing coils to detect knock.

Fortunately, the Gladiator's Pentastar is relatively straightforward. The most common "issue" isn't with the plug itself, but rather the labor involved in removing the intake manifold, and the occasional stripped thread from DIYers over-torquing the plugs (stick to the 13 lb-ft spec!). If you feel significant resistance when removing an old plug, spray a little penetrating oil down the tube, let it sit, and slowly work the plug back and forth rather than forcing it out.

Need plugs replaced? Find a shop on Repairius.