2016 Ram ProMaster: Spark Plug Type, Gap & Torque

Quick reference

Note: The 3.0L EcoDiesel engine uses glow plugs, not spark plugs. This article will focus on the 3.6L gasoline engine.

Why the right plug matters

Choosing the correct spark plug is crucial for engine performance, fuel economy, and longevity. The spark plug's primary job is to ignite the air-fuel mixture in the combustion chamber. Here's a breakdown of what makes a spark plug right for your ProMaster:

• Heat Range: This refers to the spark plug's ability to dissipate heat. A "hot" plug has a longer insulator nose, retaining more heat, while a "cold" plug has a shorter insulator nose, dissipating heat more quickly. Using a plug with the wrong heat range can lead to pre-ignition (if too hot) or fouling (if too cold). For the 2016 Ram ProMaster's 3.6L Pentastar V6, the factory-specified heat range is essential for optimal combustion.

• Electrode Metal: The material of the center and ground electrodes significantly impacts the spark plug's lifespan and performance.

  • Iridium: The OEM plugs for the 3.6L ProMaster are iridium-tipped. Iridium is an extremely hard and durable precious metal, allowing for a very fine-wire center electrode. This creates a more focused and consistent spark, leading to better throttle response and fuel efficiency. Iridium plugs have the longest service life, typically around 100,000 miles.
  • Platinum: Platinum plugs are a good mid-range option, offering a longer life than copper plugs but not as long as iridium. Double platinum plugs have platinum on both the center and ground electrodes, providing a more consistent spark over their lifespan.
  • Copper: Copper core plugs with a nickel alloy electrode are the most basic type. They have a larger diameter electrode and a shorter lifespan, typically needing replacement every 30,000 miles. While they are a cost-effective option, they are not recommended for the ProMaster's 3.6L engine, which is designed for long-life iridium plugs.

How to gap a spark plug

Properly gapping the spark plugs is a critical step in the replacement process. The "gap" is the distance between the center and ground electrodes. An incorrect gap can lead to misfires, poor fuel economy, and a rough idle.

To gap a spark plug, you'll need a feeler gauge or a spark plug gapper tool. Here's the process:

1. Check the gap: Gently insert the correct thickness gauge between the electrodes. For the 2016 ProMaster 3.6L, the gap should be 0.043 inches (1.1 mm).
2. Adjust the gap: If the gap is too wide, gently tap the ground electrode on a hard surface to close it slightly. If the gap is too narrow, use the gapper tool to carefully bend the ground electrode open. It's crucial to only bend the ground strap and never the center electrode.
3. Re-check the gap: After each adjustment, re-check the gap with the feeler gauge until it is at the correct specification.

Replacement procedure tips

The 2016 Ram ProMaster 3.6L V6 features a coil-on-plug ignition system, which simplifies the spark plug replacement process.

• Coil-on-Plug Removal: Each spark plug has its own ignition coil mounted directly on top of it. To access the spark plugs, you'll need to remove the engine cover and then disconnect the electrical connector to each coil. A single bolt holds each coil in place. Once the bolt is removed, the coil can be gently twisted and pulled straight up to remove it.

• The Anti-Seize Debate: There is some debate in the automotive community about the use of anti-seize on spark plug threads. The concern is that the lubricating properties of anti-seize can lead to over-torquing the spark plugs, which can damage the threads in the cylinder head. Most modern spark plugs have a special coating on the threads that prevents seizing, so anti-seize is not always necessary. If you do choose to use anti-seize, apply a very small amount only to the threads, making sure to keep it away from the electrodes and the porcelain insulator. Reduce the torque spec by 10-15% to avoid over-tightening.

• Dielectric Grease on Boots: It is highly recommended to apply a small amount of dielectric grease to the inside of the spark plug boot before reinstalling the ignition coil. Dielectric grease is a non-conductive, silicone-based grease that helps to seal the boot, prevent moisture from getting in, and make it easier to remove the coil in the future. It also helps to prevent voltage leaks and arcing.

Known issues

While some vehicles are known for specific spark plug-related issues, such as the Ford 3-valve Triton engines with their two-piece spark plugs that are prone to breaking during removal, the 2016 Ram ProMaster with the 3.6L Pentastar V6 does not have any widely known, common issues related to spark plug failure or replacement. The design is straightforward, and as long as the correct procedures and torque specifications are followed, the process should be trouble-free.

Need plugs replaced? Find a shop on Repairius.