2023 GMC Acadia Spark Plug Type & Gap

Quick reference

Why the right plug matters

Choosing the correct spark plug for your 2023 GMC Acadia is crucial for optimal engine performance, fuel efficiency, and longevity. Spark plugs are available in a few main types, primarily differing in their electrode material:

• Iridium: These are the most common type in modern vehicles like the Acadia. Iridium is extremely hard and has a very high melting point, allowing for very fine electrodes that produce a strong, focused spark. This leads to longer service intervals and better performance.
• Platinum: Platinum plugs offer good durability and performance, often outlasting traditional copper plugs. They typically feature a platinum disc welded to the center electrode.
• Copper: While excellent conductors, copper electrodes wear quickly due to their softer nature and lower melting point. They are generally found in older vehicles or specific high-performance applications where frequent changes are acceptable.

The "heat range" of a spark plug is also vital. A plug that's too "hot" will run too high a temperature and can lead to pre-ignition and engine damage. A plug that's too "cold" won't get hot enough to burn off deposits, leading to fouling and misfires. Automakers engineer specific heat ranges for each engine to ensure proper combustion and prevent issues. Using the OEM-specified plug ensures you have the correct heat range for your Acadia's engine.

How to gap a spark plug

Proper spark plug gap is essential for a strong, consistent spark. Too wide a gap can strain the ignition system, while too narrow a gap can lead to a weaker spark. Most modern iridium spark plugs, especially those for your 2023 GMC Acadia, come pre-gapped from the factory. It is generally recommended not to attempt to regap iridium plugs as their fine-wire electrodes are delicate and can be easily damaged. Always double-check the gap against the manufacturer's specification before installation.

If you must check the gap on an un-gapped plug or on a different type of plug (like a copper one), use a wire-type spark plug gapping tool. Gently slide the correct wire gauge between the electrodes. If adjustment is needed, carefully bend the ground electrode only, using the adjusting tool on the gapper. Never apply pressure to or pry against the center electrode.

Replacement procedure tips

Replacing spark plugs in your 2023 GMC Acadia will involve working with a coil-on-plug (COP) ignition system. This means each spark plug has its own individual ignition coil mounted directly above it. Here are some tips for a smooth replacement:

1. Disconnect the Battery: Always disconnect the negative battery terminal before starting any work on the ignition system to prevent accidental activation or electrical shorts.
2. Remove Engine Covers: You'll likely need to remove any plastic engine covers to access the ignition coils.
3. Coil-on-Plug Removal: Carefully disconnect the electrical connector from each ignition coil. Then, unbolt the coil (usually a single bolt per coil) and gently pull it straight up to remove it from the spark plug well. Avoid twisting or prying aggressively, as this can damage the coil boot or the coil itself.
4. Clean Spark Plug Wells: Before removing the old plugs, use compressed air to blow out any dirt or debris from around the spark plug wells. This prevents contaminants from falling into the combustion chamber once the old plug is removed.
5. Anti-Seize Debate: There is ongoing debate about using anti-seize on spark plug threads. Most modern spark plugs use a special coating on the threads that acts as an anti-seize agent. Applying additional anti-seize can alter the torque specification, leading to over-tightening and potential damage to the cylinder head threads. For your 2023 GMC Acadia, it's generally recommended to install the plugs dry, without anti-seize, and torque them to the manufacturer's specification. Consult your vehicle's service manual for specific recommendations.
6. Dielectric Grease: Apply a small amount of dielectric grease inside the spark plug boot of the ignition coil. This helps seal out moisture, prevents corrosion, and makes future removal easier. Be careful not to get grease on the electrical contacts.
7. Torque to Spec: Always use a torque wrench to tighten the new spark plugs to the manufacturer's specified torque. Over-tightening can strip the cylinder head threads or crack the spark plug, while under-tightening can lead to combustion gas leakage and plug overheating.

Known issues

The 2023 GMC Acadia's engines generally use reliable ignition systems and do not have widespread, well-documented spark plug-related issues akin to the Ford 3-valve 2-piece plugs or certain GM ionization-sensing coil problems. However, regular maintenance and using the correct OEM or specified aftermarket spark plugs are key to preventing individual issues such as misfires, reduced fuel economy, or premature wear due to incorrect heat range or counterfeit parts.

Need plugs replaced? Find a shop on Repairius.