2022 Ram 2500 — Spark Plug Type, Gap & Torque Specs

Quick reference

Note: Always confirm gap and torque against the label underhood or the Ram service manual for your exact VIN. Some aftermarket plugs are pre-gapped but should still be checked.

Why the right plug matters

• Heat range: The 6.4L HEMI runs hot under load. A plug with the correct heat range removes heat from the tip without running so cold that it fouls. Using a hotter or colder heat range than specified can cause misfires, pre-ignition, or deposits.
• Electrode material:
  • Iridium: Factory-style long-life choice on most late-model HEMI applications. Best durability (often 100k miles under normal conditions), strong ignitability, and stable idle.
  • Platinum: Mid-life option. Better than copper for longevity but typically shorter service life than iridium.
  • Copper/nickel: Great conductor and inexpensive, but service interval is much shorter. Not usually the OE choice on 2022 HD trucks.
• Construction and fit: The HEMI uses 16 plugs (two per cylinder). Sticking with the correct reach, seat style, and resistor design prevents piston or valve interference, thread damage, radio noise, and check-engine lights.

How to gap a spark plug

1. Inspect first: Verify part number and reach/seat match your old plug. Reject any plug with damaged threads or chipped porcelain.
2. Measure: Use a wire-type gap gauge. Slide the wire through the ground strap arc to read the actual gap.
3. Adjust lightly: If needed, bend only the ground strap—never the center electrode—using the tool’s built-in prong. Make very small adjustments and re-check.
4. Target: For the 6.4L HEMI, 0.043 in (1.1 mm) is commonly specified. Some plugs are sold pre-gapped close to this, but shipping can alter the setting.
5. Consistency: Match all 16 plugs within a thousandth or two for even combustion.

Replacement procedure tips (6.4L HEMI)

• Layout and access: The 6.4L HEMI is a coil-on-plug design with two spark plugs per cylinder. Each coil fires its primary plug and a short secondary lead connects to the companion plug. Plan extra time—there are 16 plugs.
• Preparation: Work on a cool engine. Disconnect the negative battery cable. Blow debris from plug wells with compressed air to keep grit out of the cylinders.
• Coil removal: Unplug the coil connector. Remove the coil retaining bolt and lift the coil straight up. For the second plug on each cylinder, remove the short secondary lead/boot carefully so you don’t tear the insulator.
• Plug removal: Use a 5/8-inch spark plug socket with extension. Break loose, then back out by hand. If a plug feels stuck, apply a small back-and-forth motion rather than forcing it.
• Anti-seize: Most late-model OE plugs are nickel-plated; the manufacturer generally advises no anti-seize. If you choose to use it against guidance, reduce torque by ~20–30% to avoid over-tightening. Best practice: clean, dry threads and torque to spec.
• Install: Hand-thread each new plug to avoid cross-threading in the aluminum head. Torque to 13 lb-ft (18 Nm). Reinstall coils/boots with a tiny dab of dielectric grease inside the boots to prevent moisture intrusion and future sticking.
• Final checks: Reconnect all coils and harnesses. Clear any stored misfire codes and verify smooth idle.

Known issues and notes for the 2022 Ram 2500

• 6.7L Cummins diesel: No spark plugs—ignition is by compression and fuel injection. If you’re diagnosing a no-start on the diesel, look at glow plugs/controllers (where equipped), batteries, or fuel system issues instead.
• 6.4L HEMI dual-plug service time: Expect a longer service window due to 16 total plugs. Many owners spread the job over two sessions (one bank at a time) to reduce fatigue and mistakes.
• Seized plugs in aluminum heads: Extended intervals or dusty/off-road use can promote corrosion. A cool engine and gentle break-away torque help minimize thread damage. Always start new plugs by hand.
• Water or oil in plug tubes: Coil boots can track if oil from a valve cover seep or water intrusion gets into the wells, leading to misfires. Inspect and address leaks before replacing coils or plugs.
• Not applicable here: The infamous Ford 3‑valve 2‑piece plug breakage and GM ionization-sensing coil quirks do not apply to the Ram 6.4L HEMI.

When selecting replacements, use the Mopar catalog or the NGK/Denso lookup with your VIN. Motorcraft and ACDelco are not primary suppliers for Ram, but some catalogs list cross‑references—verify reach, seat, and heat range carefully.

Need plugs replaced? Find a shop on Repairius.