2016 Ford Explorer Spark Plug Type, Gap & Torque Specs

As an ASE-certified master technician, I see plenty of 2016 Ford Explorers roll into the shop. Whether you are running the efficient 2.3L EcoBoost, the standard 3.5L naturally aspirated V6, or the twin-turbo 3.5L EcoBoost, keeping your ignition system in top shape is critical to maintaining fuel economy, power, and smooth idling. When the miles pile up, it’s time for a tune-up.

Here is the definitive guide to getting the right spark plugs, the correct gap, and the proper torque for your 2016 Ford Explorer.

Quick reference

Note: For EcoBoost engines, especially if tuned or driven under heavy loads (towing), many technicians recommend shortening the replacement interval to 60,000 miles.

Why the right plug matters

Modern Ford engines, particularly the EcoBoost variants, are incredibly sensitive to spark plug specifications. Running the correct heat range is vital; a plug that is too hot can cause pre-ignition and catastrophic engine damage under boost, while a plug that is too cold will foul out with carbon deposits.

The 2016 Explorer uses fine-wire Iridium spark plugs from the factory. Iridium is significantly harder and more durable than platinum or traditional copper. This durability is what allows Ford to confidently recommend a 100,000-mile service interval under normal driving conditions. While copper plugs offer excellent conductivity, they would burn up rapidly in these high-compression, high-heat environments. Stick to OEM Motorcraft Iridium or premium aftermarket equivalents from NGK or Denso.

How to gap a spark plug

Even if your new iridium plugs claim to be "pre-gapped," you must verify the gap before installation. Shipping drops can easily close a gap.

1. Use the right tool: Use a wire-style gap gauge or a feeler gauge. Avoid the cheap coin-style ramp gauges on iridium plugs, as sliding them can snap the brittle fine-wire center electrode.
2. Measure: Carefully pass the gauge between the center electrode and the ground strap. It should have a slight "drag."
3. Adjusting (Light bend): If the gap is too tight, use the bending tool on your gauge to gently pull the ground strap back. Never pry against the center electrode. If the gap is too loose, lightly tap the ground strap on a soft wooden workbench to close it.

Replacement procedure tips

The 2016 Explorer uses a Coil-On-Plug (COP) ignition system, meaning there are no spark plug wires or distributors—just an individual ignition coil sitting directly on top of each spark plug.

• Accessing the V6 Rear Bank: If you have the 3.5L engine (either EcoBoost or N/A), the engine is mounted transversely. The front three plugs are a breeze, but the rear three are tucked under the upper intake manifold (plenum). You will need to remove the intake plenum to access the rear coils. Buy a new upper intake manifold gasket set before starting this job.
• The Anti-Seize Debate: Motorcraft spark plugs feature a nickel-plated shell designed to prevent seizing in the aluminum cylinder head. Ford advises against using anti-seize on the threads. Adding anti-seize acts as a lubricant, which can easily cause you to over-torque the plug and strip the aluminum threads. Install them dry.
• Dielectric Grease: Apply a small dab of dielectric grease to the inside of the coil boot. This prevents moisture intrusion, stops voltage leaks (carbon tracking), and prevents the rubber boot from tearing the next time you remove it.

Known issues

Many Ford owners are haunted by the infamous 2-piece spark plug breakage issues found in the older 2004-2008 5.4L 3-valve engines. The good news? That issue does not apply to the 2016 Explorer. The 3.5L and 2.3L engines use a standard one-piece plug design that does not break off in the cylinder head.

However, EcoBoost owners should be aware of spark blowout and carbon tracking. Because of the turbochargers forcing dense air into the cylinders, the spark has a harder time jumping the gap. As spark plugs age and the gap widens, you may experience a hard misfire or hesitation under heavy acceleration. If you notice carbon tracking (thin black lightning-bolt lines) on the white porcelain insulator of your old plugs, you must replace the ignition coil boots as well, or the new plugs will instantly arc over and misfire.

Need plugs replaced? Find a shop on Repairius.