2019 GMC Acadia Spark Plug Type & Gap

Quick reference

Why the right plug matters

Spark plugs are vital for your engine's performance, fuel efficiency, and emissions. Using the correct spark plug type and ensuring it's properly gapped and torqued is critical. The "heat range" of a spark plug determines how well it dissipates heat from the combustion chamber. An incorrect heat range can lead to pre-ignition (too hot) or fouling (too cold).

When it comes to electrode material, most modern vehicles, like your 2019 GMC Acadia, come equipped with iridium spark plugs from the factory. Iridium offers superior durability and a finer electrode tip, leading to a more consistent spark and longer service intervals compared to platinum or traditional copper plugs. While platinum plugs offer a step up from copper in longevity, they don't quite match iridium. Copper plugs, though excellent conductors, have very short lifespans and are rarely found in modern vehicles as OEM equipment.

How to gap a spark plug

While most iridium and platinum spark plugs come pre-gapped from the factory, it is always a good idea to double-check, especially if you're using an aftermarket plug. For your 2019 GMC Acadia, the recommended gap is 0.043 inches (1.1 mm).

To gap a spark plug, you'll need a wire-type spark plug gauge. Avoid using a ramp-style gauge on fine-wire iridium or platinum plugs, as it can damage the delicate electrode. Gently slide the appropriate wire gauge between the center and ground electrodes. If the gap is too small, you can carefully bend the ground electrode outwards slightly. If it's too large, gently tap the ground electrode on a clean, hard surface to close the gap. Always be very careful to avoid touching or damaging the center electrode.

Replacement procedure tips

Replacing spark plugs on your 2019 GMC Acadia, regardless of whether you have the 2.5L I4 or 3.6L V6 engine, involves working with a coil-on-plug (COP) ignition system. This means each spark plug has its own individual ignition coil mounted directly on top of it.

Here's a general outline of the process and some important tips:

1. Access: Depending on your engine, you may need to remove engine covers, air intake components, or even the intake manifold (especially on the 3.6L V6 for the rear bank of cylinders) to gain proper access to all the spark plugs.
2. Coil-on-Plug Removal: Carefully disconnect the electrical connector from each ignition coil. Then, unbolt the coil (usually a single bolt) and gently twist and pull upwards to remove it from the spark plug well.
3. Cleaning: Before removing the old spark plugs, it