2024 GMC Yukon Spark Plug Type & Gap Guide

Quick reference

Why the right plug matters

Selecting the correct spark plug for your 2024 GMC Yukon is crucial for optimal engine performance, fuel efficiency, and longevity. Spark plugs are available in various materials, each with unique characteristics impacting their performance and lifespan.

• Iridium: This is the most common and recommended material for modern engines like those in the 2024 Yukon. Iridium plugs feature a fine-wire electrode that provides a very focused spark, leading to better combustion and extended service life, often exceeding 100,000 miles. They are extremely durable and resist wear exceptionally well.
• Platinum: Platinum plugs are a step up from copper, offering improved durability and a longer lifespan. They typically feature a platinum disc on the center electrode and/or ground electrode. While good, they generally don't last as long or perform as efficiently as iridium plugs.
• Copper: Copper plugs are the traditional and most basic type. They have excellent conductivity but wear out much faster due to the softer nature of copper. They are rarely recommended for modern vehicles due to their short lifespan and inability to handle the high temperatures and voltages of contemporary ignition systems effectively.

The "heat range" of a spark plug is another critical factor. A spark plug's heat range refers to its ability to dissipate heat. A "cold" plug dissipates heat quickly, while a "hot" plug retains more heat. Using the wrong heat range can lead to pre-ignition (if the plug is too hot) or fouling (if the plug is too cold). Always stick to the OEM-specified heat range.

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. For your 2024 GMC Yukon, the recommended gap is 0.040 inches (1.0 mm). Always double-check the gap before installation, even if the plugs are "pre-gapped," as they can be knocked out of spec during shipping.

To gap a spark plug, you'll need a spark plug gapping tool, commonly a wire-type or coin-style gauge:

1. Measure: Insert the appropriate wire gauge or the edge of the coin-style gauge between the electrodes. It should slide in with a slight drag.
2. Adjust (if needed): If the gap is too small, use the gapping tool's adjustment tab to gently bend the ground electrode outwards. If the gap is too large, carefully tap the ground electrode on a hard, non-abrasive surface to push it inwards. Never bend the center electrode.
3. Re-measure: Re-check the gap to ensure it meets the specification.

Replacement procedure tips

Changing spark plugs on your 2024 GMC Yukon's 5.3L or 6.2L V8 engine is a manageable DIY task, but careful attention to detail is key.

• Coil-on-plug removal: Both V8 engines utilize a coil-on-plug (COP) ignition system. Each spark plug has its own ignition coil mounted directly on top. To access the spark plugs, you'll need to disconnect the electrical connector from each coil and then unbolt and remove the coil. Be gentle with the connectors, as they can become brittle over time.
• Anti-seize debate: There's ongoing debate about using anti-seize compound on spark plug threads. Most modern spark plugs (especially those with nickel-plated shells) do not require it and, in fact, manufacturers like ACDelco and NGK often advise against it. The reason is that anti-seize can act as a lubricant, leading to over-torquing and potential damage to the cylinder head threads. If you choose to use it (e.g., on older, non-plated plugs), reduce the torque specification by approximately 10-20%.
• Dielectric grease on boots: Applying a small amount of dielectric grease inside the spark plug boot (the part that connects to the coil or wire) is a good practice. This grease helps seal out moisture, prevents corrosion, and makes future removal easier.
• Torque properly: Always use a torque wrench to tighten the new spark plugs to the manufacturer's specification (15 lb-ft / 20 Nm). Over-tightening can strip the threads in the cylinder head, a costly repair. Under-tightening can cause the plug to vibrate loose and lead to misfires.

Known issues

For the 2024 GMC Yukon's 5.3L and 6.2L V8 engines, there are no widespread "known issues" specific to spark plugs that are comparable to those seen in some other vehicles (like the notorious Ford 3-valve 2-piece spark plug breakage). However, like any modern engine, consistent maintenance is key. Misfires can sometimes be attributed to fouled plugs if oil consumption is high or if fuel quality is consistently poor.

Need plugs replaced? Find a shop on Repairius.