ACDelco GM Original Equipment Iridium Spark Plug
OE
Pack of 4

ACDelco GM Original Equipment Iridium Spark Plug

GM Part #12683541

ACDelco Part #41-156

MSRP$68.88*

ACDelco GM Original Equipment Iridium Spark Plugs are designed, engineered, and tested to rigorous standards, and are backed by General Motors.

  • Built to handle the demands of stop-and-go city traffic
  • Reliable ignition for daily commuting in all weather conditions
  • Provides consistent performance during long highway road trips

Pack of 4

About this product

ACDelco GM Original Equipment Iridium Spark Plugs are designed, engineered, and tested to rigorous standards, and are backed by General Motors. When your vehicle struggles with hard starting, rough idling, or engine misfires, replacing worn ignition components can restore smooth acceleration and consistent power. Today's advanced engines demand precise ignition timing, efficient fuel combustion, and consistent power delivery across thousands of firing cyclesѡnd the spark plug stands as the critical component that makes it all possible. Engineered with a core that helps provide great heat transfer and optimize durability, along with a coating that helps reduce corrosion, this part is validated to deliver reliable performance under demanding conditions. By supporting proper timing and working seamlessly with your ignition coil, it prevents hesitation when pressing the gas pedal and plays a vital role in your vehicle emission controls. Whether you are navigating stop-and-go city traffic or taking long highway road trips, a fresh spark ensures reliable cold starts and helps maintain optimal fuel economy. The iridium technology provides outstanding suppression characteristics that deliver reliable performance with its specialized corrosion resistent coating. ACDelco GM Original Equipment parts are the true OE parts installed during the production or validated by General Motors for GM vehicles.

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  • Built to handle the demands of stop-and-go city traffic
  • Reliable ignition for daily commuting in all weather conditions
  • Provides consistent performance during long highway road trips
  • Supports the entire ignition system for proper timing
  • Ignites the air and fuel mixture in the combustion chamber
  • Delivers the spark needed to start your engine
  • Features specialized corrosion resistant coating to help protect your replacement spark plugs
  • GM Engineers design and validate OE parts specifically for your Chevrolet, Buick, GMC, or Cadillac vehicle
  • Original equipment parts are designed to work with your GM vehicle safety systems -- aftermarket replacement parts may not meet the same OE safety regulations, depending on the part type

Product Specifications

Gap Size0.03 in / 0.7 mm
Reach0.98 in / 25 mm
ClassificationOE
Insulator Height2.07 in / 52.5 mm
Seat TypeTapered
Washer IncludedNo
Hex Size14 MM
Resistor TypeYes
Ground Electrode Tip DesignStandard
Ground ConfigurationStandard
Ground Electrode Quantity1
Center Electrode Tip MaterialIridium
Manufacturer Heat Range8

84 Months/Unlimited Miles Limited Warranty (Parts Only). First 24 Months Labor Included. See ACDelco.com for more details.

Please visit our warranty page on Gmparts.com for full warranty details.

Visually inspect spark plugs for signs of wear. Follow these steps for removing spark plugs for inspection, servicing or replacement:

  • Grasp the spark plug boot and gently rotate it 90 degrees counterclockwise. Pull the spark plug boot and cable away from the spark plug. If necessary, use a spark plug boot removing tool. DO NOT grab or violently pull spark plug cables
  • Brush or air blast dirt away from the well areas before removing spark plugs. CAUTION: Use goggles to protect eyes from debris when applying compressed air to spark plug wells.
  • Use the correct deep socket size to loosen each spark plug one or two turns. NOTE: To remove spark plugs from aluminum heads, allow the engine to cool. The heat of the engine, in combination with a spark plug that is still hot, may cause the spark plug threads to strip the cylinder head upon removal.
  • Remove each spark plug and place each one in a tray by cylinder number. This will help identify and relate any unusual condition to the cylinder involved.
  • Apply dielectric grease into the boot area to reduce the chance of exterior tracking on the buttress tower of the spark plug. This grease also promotes a good heat transfer between the spark terminal screw and boot terminal.
  • Before installing new spark plugs, use a gap guide to make sure your new spark plugs have the correct gap. NOTE: ACDelco GM OE Iridium Spark Plugs are pre-gapped during manufacturing. Never attempt to gap an ACDelco GM OE Iridium Spark Plug. You could damage the spark plug. Replace any incorrectly gapped ACDelco GM OE Iridium Spark Plugs with plugs that are correctly gapped.
  • Install spark plugs or glow plugs to the proper torque per the manufacturers’ specification.

Signs of wear for spark plugs include but are not limited to:

  • Your engine having trouble starting, hesitating, or cutting out
  • Lack of acceleration or loss of speed when driving uphill under load
  • Cracks in the upper or lower portion of the spark plug insulator
  • Chipped or broken insulator tips
  • Damaged spark plug boots

ModelBody StyleTrimYear(s)
TerrainElevation, SL, SLE, SLT2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025, 2026, 2027

Frequently Asked Questions

Yes, this interval depends on what type of spark plug your vehicle requires. Refer to your owner’s manual or contact your vehicle’s manufacturer for more information.

Yes, if it is the scheduled time for spark plug replacement. It is okay to replace one spark plug if it is fouled or damaged prior to scheduled maintenance, provided the source of the damage is found and corrected.

Yes. Diesel engines require glow plugs because diesel engines operate differently than gas engines. ACDelco Professional Glow Plugs are specially designed to give diesel engines the heat they need for their cold starts. Refer to your owner’s manual or contact your vehicle’s manufacturer for more information.

Yes. When ACDelco spark plugs are manufactured, they are pre-gapped to the correct gap specification.

Not always, but you should inspect your spark plug wires for wear when replacing your spark plugs. Refer to your vehicle owner’s manual or contact the manufacturer for more information.

Yes, pre-ignition can cause serious damage to your engine. Pre-ignition is the ignition of fuel before the actual spark occurs, which causes a rapid temperature rise in the combustion chamber that can damage engine components and melt spark plug electrodes. Causes of pre-ignition include but are not limited to a buildup of deposits that can become incandescent in the combustion chamber, improper installation torque being applied to spark plugs, and having spark plugs with a heat range that is too hot for the engine’s operating condition.

No, cleaning your old spark plugs is not recommended. Dirty, fouled spark plugs may also have broken or chipped insulator tips, worn electrodes, or worn or missing side wires. These conditions severely affect spark plug performance. Replace your dirty, fouled spark plugs with new ACDelco spark plugs.

Yes, ACDelco has marine spark plugs for many applications.