2022 GMC Yukon Spark Plug Type & Gap

Quick reference

Why the right plug matters

Choosing the correct spark plug for your 2022 GMC Yukon is crucial for optimal engine performance, fuel efficiency, and longevity. Spark plugs are not "one size fits all." Key factors like heat range and electrode material greatly influence how your engine runs.

Heat Range: This refers to the plug's ability to dissipate heat. A "hot" plug retains more heat, while a "cold" plug dissipates it faster. An incorrect heat range can lead to pre-ignition (too hot) or fouling (too cold). The OEM-specified heat range ensures the plug operates within the ideal temperature window for your Yukon's engine.

Electrode Metal:

• Iridium: This is the most common and recommended material for modern engines like your 2022 Yukon. Iridium plugs offer exceptional durability and a fine-wire electrode, which provides a more consistent, powerful spark. They have a lifespan of 90,000 to 120,000 miles.
• Platinum: Platinum plugs are a step up from copper, offering better durability and a longer lifespan (around 60,000 miles). They use a platinum disc welded to the center or ground electrode.
• Copper: While excellent conductors, copper plugs wear out much faster due to their softer material. They are typically found in older vehicles or those with specific performance requirements and usually last 30,000 miles or less.

Using the specified iridium plugs ensures your Yukon's engine runs cleanly and efficiently for extended periods.

How to gap a spark plug

Properly gapping a spark plug creates the ideal distance between the center and ground electrodes for the spark to jump. While most iridium and platinum plugs come pre-gapped, it's always wise to double-check, especially if you opted for a different brand.

1. Obtain a Wire Gauge: Use a circular wire-type gap gauge. Avoid the cheaper ramp-style gauges, as they can damage the delicate iridium tips.
2. Measure the Gap: Carefully slide the correct wire gauge (0.040 inches or 1.0 mm for your Yukon) between the electrodes. It should slide with slight resistance.
3. Adjust (if necessary): If the gap is too small, use the bending tool on the gauge to slightly pry open the ground electrode. If the gap is too wide, gently tap the ground electrode on a clean, hard surface to close it. Be extremely careful not to touch the center electrode, as it is fragile.
4. Re-check: Always re-measure the gap after any adjustment to ensure accuracy.

Note: The 3.0L Duramax diesel engine does not use spark plugs, as diesel engines ignite fuel via compression rather than an electrical spark.

Replacement procedure tips

Replacing spark plugs on your 2022 GMC Yukon (5.3L or 6.2L V8) can be a DIY task if you're mechanically inclined. Here are some crucial tips:

1. Preparation: Allow the engine to cool completely before starting. Hot aluminum heads are susceptible to stripped threads. Disconnect the negative battery terminal.
2. Coil-on-Plug Removal: Your Yukon uses a coil-on-plug (COP) ignition system. Each spark plug has its own ignition coil mounted directly above it. Carefully disconnect the electrical connector from each coil and then remove the retaining bolt(s). Gently twist and pull the coil upward to free it from the spark plug. Be mindful of any brittle wiring.
3. Cleanliness is Key: Before removing the old 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.
4. Anti-Seize Debate: There's ongoing debate about using anti-seize on spark plug threads. ACDelco, the OEM supplier, generally recommends against it for factory-coated plugs, as it can alter torque readings and potentially lead to over-tightening. If you do use it, apply a very thin coat and reduce the torque specification by about 10-15%. For your Yukon, sticking to the specified torque without anti-seize on factory-coated plugs is usually the safest bet.
5. Dielectric Grease: Apply a small amount of dielectric grease inside the boot of each ignition coil before reinstallation. This helps seal out moisture, prevents corrosion, and makes future removal easier. Do not get dielectric grease on the spark plug electrode.
6. Torque Wrench: Always use a torque wrench to tighten the new spark plugs to the specified 11 lb-ft (15 Nm). Over-tightening can strip cylinder head threads or damage the spark plug, while under-tightening can lead to blow-out or poor heat transfer.

Known issues

Fortunately, the 2022 GMC Yukon's V8 engines (L84 and L87) do not have widespread, notorious spark plug issues like some older Ford 3-valve engines (e.g., broken 2-piece plugs). General Motors' modern V8s are known for their robust design.

However, it's still important to be aware of potential, albeit less common, problems:

• Oil Fouling: Excessive oil consumption can lead to oil-fouled spark plugs, causing misfires. This usually indicates an underlying engine issue rather than a spark plug defect.
• Heat Range Issues (Aftermarket): Using a spark plug with an incorrect heat range from an aftermarket supplier could lead to pre-ignition or excessive carbon buildup, but this is avoided by sticking to OEM or recommended aftermarket options.
• Ionization Sensing: GM's newer engines use ionization sensing technology through the spark plugs to detect misfires and optimize combustion. Using non-spec spark plugs can interfere with this system, leading to drivability problems or diagnostic trouble codes (DTCs).

Sticking to the recommended ACDelco or NGK iridium plugs for your 2022 GMC Yukon will help ensure trouble-free operation.

Need plugs replaced? Find a shop on Repairius.