2019 Chevrolet Silverado 2500HD Spark Plug Type & Gap

Quick reference

Why the right plug matters

Spark plugs are a vital component of your 2019 Chevrolet Silverado 2500HD's ignition system, igniting the air-fuel mixture in your engine's cylinders. Using the correct spark plug type, heat range, and gap is crucial for optimal engine performance, fuel efficiency, and longevity.

Heat Range: The heat range of a spark plug dictates its ability to dissipate heat. A plug that's too "cold" can lead to carbon fouling, while one that's too "hot" can cause pre-ignition and engine damage. The factory-specified plug for your 6.0L L96 V8 is designed for the ideal heat range.

Electrode Metal: Different spark plug electrode materials offer varying lifespans and performance characteristics:

• Iridium: Found in your OEM ACDelco 41-110 plugs, iridium plugs offer exceptional durability and a long lifespan (typically 100,000 miles or more) due to their extremely hard and corrosion-resistant iridium center electrode. They provide consistent, powerful sparks.
• Platinum: Platinum plugs (either single or double platinum) also offer good longevity, though generally not as long as iridium. They are an improvement over copper plugs in terms of lifespan and performance.
• Copper: While excellent conductors of electricity, copper electrodes wear down relatively quickly, requiring more frequent replacement. They are not typically used as OEM in modern engines like your Silverado's.

How to gap a spark plug

Properly gapping a spark plug ensures the correct distance between the center and ground electrodes for an optimal spark. Even though many modern plugs, especially iridium ones, come pre-gapped, it's always a good idea to double-check.

1. Obtain a gap tool: Use a wire-type spark plug gap tool, not a flat disc type, as the flat type can damage fine-wire electrodes.
2. Check the gap: Carefully slide the correct thickness wire from your gauge between the electrodes. It should have a slight drag.
3. Adjust if necessary: If the gap is too small, use the bending tool on the gauge to gently pry the ground electrode outwards. If the gap is too wide, carefully tap the ground electrode on a hard, flat surface to close it. Be extremely careful not to damage the delicate iridium tip.

For your 2019 Silverado 2500HD's 6.0L L96 V8, the recommended spark plug gap is 0.040 inches (1.02 mm).

Replacement procedure tips

Replacing spark plugs on your 2019 Chevrolet Silverado 2500HD's 6.0L L96 V8 is a relatively straightforward job for a DIYer with the right tools and a little patience. Here are some tips:

• Coil-on-Plug Removal: Your Silverado uses a coil-on-plug ignition system, meaning each spark plug has its own ignition coil mounted directly on top of it. To access the plugs, you'll need to disconnect the electrical connector from each coil and then remove the coil mounting bolt(s). Gently twist and pull the coil straight up to remove it from the spark plug well.
• Anti-Seize Debate: There is much debate about using anti-seize on spark plug threads. Most modern spark plug manufacturers, including ACDelco, recommend against using anti-seize because plugs are typically manufactured with a special coating on the threads. Applying anti-seize can alter the torque readings, potentially leading to over-tightening and plug or cylinder head damage. Follow the manufacturer's recommendation.
• Dielectric Grease on Boots: A small amount of dielectric grease applied to the inside of the spark plug boot (the part of the coil that connects to the plug) can help prevent moisture intrusion, aid in heat transfer, and make future removal easier. Do NOT get dielectric grease on the spark plug electrodes.
• Torque Specs: Always use a torque wrench to tighten spark plugs to the specified value of 11 lb-ft (15 Nm). Overtightening can damage the spark plug or the cylinder head threads, while undertightening can lead to combustion gas leakage and plug overheating.
• One at a Time: To avoid mixing up ignition coils or dropping debris into open cylinders, it's often best to work on one spark plug at a time: remove coil, remove plug, install new plug, install coil.

Known issues

Fortunately, the 6.0L L96 V8 engine in your 2019 Chevrolet Silverado 2500HD is generally not prone to specific spark plug-related issues like the famously problematic two-piece spark plugs in some Ford 3-valve engines or the ionization-sensing coil problems seen in some earlier GM 5.3L engines. With proper maintenance and the correct spark plugs, you should experience reliable ignition performance.

Need plugs replaced? Find a shop on Repairius.