2022 GMC Acadia Spark Plug Type & Gap Guide

The 2022 GMC Acadia offers a comfortable ride and capable performance, driven by either a turbocharged 2.0L four-cylinder or a naturally aspirated 3.6L V6. To keep your SUV running smoothly, maintaining the ignition system is critical. Below is a comprehensive guide to the spark plug specifications, torque ratings, and replacement tips for the 2022 GMC Acadia.

Quick reference

(Note: Motorcraft is a Ford brand and is not recommended as an OEM replacement for General Motors vehicles like the Acadia.)

Why the right plug matters

Modern General Motors engines are incredibly sensitive to spark plug specifications, particularly regarding heat range and electrode metal.

The 2022 GMC Acadia uses Iridium spark plugs from the factory. Iridium is significantly harder and more durable than traditional copper or platinum. This allows the center electrode to be wire-fine, improving ignitability and combustion efficiency while lasting nearly 100,000 miles in naturally aspirated applications. Using a cheaper copper or platinum plug in these engines can lead to a misfire condition, poor fuel economy, and premature plug wear. Additionally, using a plug with the wrong heat range can cause pre-ignition (if too hot) or severe carbon fouling (if too cold).

How to gap a spark plug

While modern ACDelco and NGK iridium spark plugs come pre-gapped from the factory, they can occasionally be bumped during shipping. It is always best practice to verify the gap before installation.

1. Use a wire-style gauge: Avoid using a coin-style ramp gauge on iridium plugs. The fragile iridium center tip can easily snap off if scraped. Instead, use a wire feeler gauge.
2. Measure gently: Slide the correct wire size 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 a proper gapping tool to apply a light bend to the ground strap. Never pry against the center iridium electrode. If the gap is too wide, gently tap the ground strap on a soft wooden workbench to close it slightly.

Replacement procedure tips

The 2022 GMC Acadia utilizes a Coil-on-Plug (COP) ignition system, meaning there is no distributor or spark plug wires. Instead, an individual ignition coil sits directly on top of each spark plug.

• Accessing the plugs: For the 2.0L Turbo, the spark plugs are easily accessible under the top engine cover. However, the 3.6L V6 is mounted transversely. Accessing the rear bank (firewall side) requires removing the upper intake manifold (plenum). Ensure you have a new intake manifold gasket on hand before starting this job.
• The anti-seize debate: Modern ACDelco and NGK spark plugs feature a specialized trivalent metal plating that prevents thread seizing in the aluminum cylinder head. GM strictly advises against using anti-seize on these threads. Adding anti-seize acts as a lubricant, which can easily cause you to over-torque the plugs and strip the cylinder head threads. Install them dry.
• Dielectric grease: Always apply a small, pea-sized dab of dielectric grease to the inside of the new spark plug boot. This prevents moisture intrusion, stops voltage voltage leaks, and makes the boot easier to remove during the next service interval.

Known issues

While you won't face the infamous Ford 3-valve 2-piece spark plug breakage on a GMC, you still need to be cautious.

• Direct Injection Carbon: Both the 2.0L and 3.6L engines are Direct Injected (SIDI). While not a spark plug defect, carbon can build up on the intake valves, which sometimes mimics a spark plug misfire. If replacing the plugs doesn't cure a rough idle, consider a professional intake valve cleaning.
• Cracked Porcelain: When installing plugs in the tight confines of the 3.6L rear bank, ensure your spark plug socket is perfectly straight. Any side-loading on your extension can easily crack the ceramic porcelain of the new plug, resulting in an immediate misfire upon startup. Use a magnetic spark plug socket with a built-in swivel for the safest installation.

Need plugs replaced? Find a shop on Repairius.