2017 GMC Sierra 1500 Spark Plug Type & Gap

Quick reference

Why the right plug matters

Spark plugs are a small but mighty component in internal combustion engines, responsible for igniting the air-fuel mixture that powers your 2017 GMC Sierra 1500. Using the correct spark plug for your specific engine is crucial for optimal performance, fuel efficiency, and to prevent potential damage.

Heat Range: Spark plugs are designed with a specific "heat range" – their ability to dissipate heat. A plug that's too "cold" (dissipates heat too quickly) can lead to fouling, where carbon deposits build up on the plug, causing misfires. One that's too "hot" (dissipates heat too slowly) can lead to pre-ignition and detonation, which can severely damage engine components. The OEM plugs (ACDelco 41-162) are engineered to maintain the ideal operating temperature for your Sierra's engine.

Electrode Metal: The material of the center and ground electrodes significantly impacts a spark plug's lifespan and performance:

• Copper: Traditionally, copper plugs have excellent conductivity but wear relatively quickly. They typically have a large diameter center electrode, which requires more voltage to spark.
• Platinum: Platinum plugs offer improved durability over copper due to their higher melting point. They often feature a finer center electrode, demanding less voltage and providing a more consistent spark.
• Iridium: The most advanced and durable type, iridium plugs have an extremely high melting point, allowing for very fine center electrodes. This results in the most efficient and powerful spark, excellent durability, and extended replacement intervals. The ACDelco 41-162 and recommended aftermarket plugs for your Sierra are iridium, hence the long service life.

How to gap a spark plug

Properly gapping a spark plug ensures a strong, consistent spark. While most iridium plugs come pre-gapped from the factory, it's always a good idea to verify the gap, especially with aftermarket plugs. However, never try to gap fine-wire iridium or platinum plugs using traditional gapping tools. The delicate electrodes can be easily damaged.

To check the gap on your 2017 GMC Sierra's iridium plugs, use a wire-style or coin-style spark plug gap tool. Gently slide the appropriate wire gauge or the edge of the coin tool into the gap between the center and ground electrodes. It should have a slight drag. If adjustment is needed, only bend the ground electrode very carefully and gently. Never bend the center electrode.

Replacement procedure tips

Replacing spark plugs on your 2017 GMC Sierra 1500 (with the 4.3L V6, 5.3L V8, or 6.2L V8) is a straightforward process, but a few tips can make it smoother:

• Coil-on-Plug Removal: Your Sierra uses a coil-on-plug (COP) ignition system, meaning each spark plug has its own ignition coil directly above it. To access the spark plugs, you'll need to disconnect the electrical connector from each coil and then remove the coil mounting bolt. Gently twist and pull upwards on the coil to remove it from the spark plug. Avoid yanking on the electrical wires.
• Anti-Seize Debate: There's a long-standing debate about using anti-seize on spark plug threads. For modern spark plugs with nickel-plated shells, manufacturers generally advise against anti-seize. The plating itself acts as an anti-seize agent, and adding more can alter torque readings, leading to over-tightening or under-tightening. Follow the torque specifications precisely.
• Dielectric Grease on Boots: A small amount of dielectric grease applied inside the spark plug boot (where it contacts the ceramic insulator of the plug) can help prevent moisture from entering and makes future removal easier. However, be careful not to get any grease on the metal terminals, as it can interfere with electrical conductivity.
• Only Replace One at a Time: To avoid mixing up spark plug wires or coils, it's a good practice to replace one spark plug at a time, from start to finish, before moving to the next.

Known issues

Fortunately, the 2017 GMC Sierra 1500 engines (4.3L LV3, 5.3L L83, 6.2L L86) do not have widespread, well-documented spark plug-related issues like the Ford 3-valve 2-piece spark plug breakage or certain GM engines with ionization-sensing coils. The direct injection systems used in these engines can sometimes lead to carbon buildup on intake valves, but this is a separate issue from spark plug function itself.

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