2024 GMC Acadia Spark Plug Type & Gap Guide

As an ASE-certified master technician, I can tell you that the completely redesigned 2024 GMC Acadia brings a significant shift under the hood. Replacing the previous generation's V6 and 2.0L turbo options is a robust, single-powertrain setup: a 2.5L Turbocharged 4-cylinder (LK0). Because this is a high-compression, forced-induction engine, having the correct spark plugs with the exact gap is absolutely critical for performance, fuel economy, and preventing catastrophic pre-ignition.

Here is your master guide to the spark plug specifications, torque ratings, and replacement intervals for the 2024 GMC Acadia.

Quick reference

Note: Always verify the exact part number with your VIN at the parts counter, as GM frequently supersedes ACDelco part numbers.

Why the right plug matters

Modern forced-induction engines like the 2.5L Turbo in the 2024 Acadia are highly sensitive to ignition variables.

• Heat Range: The heat range determines how quickly the spark plug transfers heat from the firing tip to the cylinder head. A plug that runs too hot in a turbo engine can cause pre-ignition (detonation), which can destroy pistons. If it runs too cold, it will foul out with carbon. Always stick to the OEM specified heat range.
• Electrode Metal (Iridium vs Platinum vs Copper): The 2.5T strictly requires Iridium spark plugs. Iridium is significantly harder and more durable than platinum or traditional copper. The fine-wire iridium center electrode requires less voltage to jump the gap, ensuring a reliable spark even under high boost pressures when the dense air/fuel mixture tries to "blow out" the spark. Never downgrade to copper or standard platinum plugs in this engine.

How to gap a spark plug

While most premium iridium plugs come pre-gapped from the factory, they can be bumped and knocked out of spec during shipping. You must verify the 0.028" gap before installation.

1. Use the right tool: Do not use a cheap coin-style gapper, as you can easily snap off the ultra-thin iridium center electrode. Use a wire-type gauge or a specialized feeler gauge.
2. Measure carefully: Slide the 0.028" wire between the center and ground electrode. It should pass through with a slight "drag."
3. Adjusting the gap: If the gap is too tight, use the bending tool on your gauge to lightly pry the ground strap up. Do not pry against the center electrode! If the gap is too wide, gently tap the ground strap on a soft wooden workbench to close it slightly. Re-measure until perfect.

Replacement procedure tips

The 2024 Acadia utilizes a Coil-on-Plug (COP) ignition system. Fortunately, the inline-4 layout makes accessing the plugs relatively straightforward once the engine cover and intake piping are out of the way.

• Coil-on-plug removal: Unclip the wiring harness connectors to the ignition coils carefully. The plastic locking tabs become brittle with heat over time. Remove the 10mm retaining bolt, then twist the coil slightly as you pull up to break the seal of the rubber boot.
• The anti-seize debate: Most modern ACDelco and NGK premium spark plugs feature a specialized trivalent metal plating on the threads. Do not use anti-seize. Adding anti-seize acts as a lubricant, which throws off your torque wrench readings. Torqueing to 15 lb-ft with anti-seize can easily result in over-tightening and stripping the aluminum cylinder head threads. Install them dry.
• Dielectric grease: Apply a small pea-sized dab of dielectric grease to the inside tip of the ignition coil boot before reinstalling. This prevents moisture intrusion, stops voltage leaks (carbon tracking), and ensures the boot won't fuse to the porcelain of the new plug for the next 60,000 miles.

Known issues

Because the 2.5L Turbo (LK0) is a relatively new architecture for GM, we don't see the historical nightmares of decades past (like the infamous Ford 3-valve 2-piece plug breakage). However, there is one critical thing to watch for on modern GM turbo engines: Carbon Tracking.

If you notice a misfire under heavy acceleration, pull the coils and inspect the white porcelain of the spark plugs. If you see thin, pencil-like gray or black lines running vertically down the porcelain, the spark is jumping outside the plug. This ruins both the plug and the coil boot. If you find carbon tracking, you must replace the spark plug and the coil boot simultaneously, or the misfire will return immediately.

Need plugs replaced? Find a shop on Repairius.