2014 Ram 2500 Spark Plug Specs & Replacement Guide

Quick reference

Why the right plug matters

Choosing the correct spark plug for your 2014 Ram 2500 is critical for optimal engine performance, fuel efficiency, and longevity. Spark plugs are more complex than they appear, with specific characteristics tailored to your engine's design.

• Heat Range: This refers to the plug's ability to dissipate heat. A "hot" plug retains more heat and is suitable for engines that run cooler, preventing fouling. A "cold" plug dissipates heat quickly and is needed for high-performance or hard-working engines to prevent pre-ignition. Using the wrong heat range can lead to engine damage or fouled plugs.

• Electrode Metal: The material of the spark plug electrodes significantly impacts durability and performance.

  • Copper: Traditional and excellent at conducting electricity, copper plugs have a shorter lifespan (around 30,000 miles) due to their softer electrode material. They are often the OEM choice for engines designed to use them, like the HEMI, as they provide strong ignition.
  • Platinum: Platinum is harder and more durable than copper, allowing for finer electrodes and a longer lifespan (typically 60,000-80,000 miles). They offer consistent performance over time.
  • Iridium: The hardest and most durable of the three, iridium allows for extremely fine electrodes, producing a very concentrated spark. Iridium plugs offer the longest lifespan (often 100,000+ miles) and are excellent for fuel efficiency and performance. While the OEM copper plug is specified for the HEMI, many owners upgrade to iridium for extended service intervals and often improved performance.

How to gap a spark plug

Properly gapping your spark plug ensures the correct distance between the center and ground electrodes for an optimal spark. Even "pre-gapped" plugs should always be checked, as shipping and handling can alter the gap.

1. Obtain a Gap Tool: Use a wire-type spark plug gap gauge, not a ramp-style tool. Ramp gauges can damage fine-wire iridium or platinum electrodes.
2. Measure the Gap: Carefully slide the appropriate wire from the gauge between the electrodes. It should slide in with a slight drag.
3. Adjust (if needed): If the gap is too small, gently pry the ground electrode only away from the center electrode using the adjustment notch on your gap tool. If the gap is too large, carefully tap the ground electrode on a clean, hard surface to close it slightly. Never bend the center electrode.
4. Re-Measure: Always re-measure after any adjustment to ensure accuracy.

Replacement procedure tips

Replacing spark plugs on your 2014 Ram 2500 5.7L or 6.4L HEMI engine can be a bit more involved due to the coil-on-plug setup and the number of spark plugs (16 total – two per cylinder).

1. Cool Engine: Always work on a completely cool engine to prevent seizing spark plugs in hot aluminum cylinder heads and to avoid burns.
2. Access: You'll need to remove the engine cover. For the HEMI, the eight spark plugs on the passenger side are relatively straightforward, but the driver's side plugs, especially numbers seven and eight at the very rear, can be challenging due to firewall clearance. Specialty spark plug swivel sockets and extensions are your friend here.
3. Coil-on-Plug Removal: Carefully disconnect the electrical connector from each ignition coil. Then, unbolt the coil (if applicable) and gently twist and pull to remove the coil boot from the spark plug. Be gentle to avoid damaging the coil or boot.
4. Air Blow-Out: Before removing any spark plugs, use compressed air to blow out any dirt and debris from around the spark plug wells. This prevents contaminants from falling into the combustion chamber once the plug is removed.
5. Anti-Seize Debate: For spark plugs going into aluminum cylinder heads, there's an ongoing debate about anti-seize. Most modern spark plug manufacturers now apply a proprietary coating to the plug threads, making anti-seize unnecessary and, in some cases, detrimental as it can alter torque readings. Refer to your spark plug manufacturer's recommendations. If you do use anti-seize (and only a very small amount), reduce the torque specification by 10-20% as anti-seize acts as a lubricant.
6. Dielectric Grease: Apply a small amount of dielectric grease inside the spark plug boot (where it contacts the ceramic insulator of the spark plug). This helps to seal out moisture, prevents sticking, and makes future removal easier.
7. Torque Wrench: Always use a torque wrench to tighten spark plugs to the manufacturer's specification (13 lb-ft / 17.5 Nm). Overtightening can strip threads or crack the spark plug insulator, while undertightening can cause the plug to loosen and lead to misfires or damage.

Known issues

For the 2014 Ram 2500 with the 5.7L or 6.4L HEMI, there aren't widespread "known issues" regarding spark plug breakage or unique removal challenges like those found in some other engines (e.g., Ford's problematic 3-valve 2-piece plugs).

However, a common issue can arise from neglecting spark plug replacement intervals. Over time, worn electrodes can put excessive strain on the ignition coils, leading to premature coil failure. Misfires due to worn plugs are also common, which can negatively impact performance and fuel economy.

Need plugs replaced? Find a shop on Repairius.