2017 Chevrolet Malibu Spark Plug Guide

Quick reference

Why the right plug matters

Choosing the correct spark plug for your 2017 Chevrolet Malibu is crucial for optimal engine performance, fuel efficiency, and longevity. The spark plug's primary job is to ignite the air-fuel mixture in the combustion chamber, and several factors influence how well it does this job.

Heat Range: Staying Cool Under Pressure

Spark plugs are designed with a specific "heat range," which refers to their ability to dissipate heat from the combustion chamber. A "hotter" plug has a longer insulator nose, which retains more heat, while a "colder" plug has a shorter insulator nose, dissipating heat more quickly. Using a plug with an incorrect heat range can lead to significant problems:

• Too Hot: Can cause pre-ignition (fuel igniting before the spark) or detonation (uncontrolled combustion), leading to engine damage.
• Too Cold: Can lead to fouling, where carbon deposits build up on the plug, preventing a strong spark.

Your Malibu's engine, whether the 1.5L or 2.0L turbocharged inline-four, is a finely tuned machine. GM engineers specify a particular heat range to ensure the spark plugs operate within their optimal temperature window, preventing both pre-ignition and fouling.

Electrode Metal: The Spark of Innovation

Modern spark plugs utilize various electrode materials, each with unique properties affecting their lifespan and performance:

• Iridium: This is the most common material for modern engines, including your 2017 Malibu. Iridium is incredibly hard and has a very high melting point, allowing for very fine electrodes. This results in a stronger, more focused spark and extended service intervals (typically 100,000 miles or more).
• Platinum: Platinum plugs also offer excellent durability and a longer lifespan than copper, often used in vehicles with recommended change intervals around 60,000-100,000 miles. They usually feature a platinum disc welded to the center electrode.
• Copper: While copper is an excellent conductor of electricity, it is a relatively soft metal with a lower melting point. Copper plugs typically have a larger center electrode and a shorter lifespan, usually requiring replacement every 30,000 miles or less. While not typically found in modern, high-performance engines like those in the Malibu, they are common in older vehicles.

The ACDelco 41-167 plugs specified for your Malibu are iridium-tipped, providing the best balance of performance and longevity.

How to gap a spark plug

While many modern iridium spark plugs come pre-gapped from the factory, it's always a good idea to double-check the gap before installation, especially with high-performance or turbocharged engines like those in the Malibu. The gap is the distance between the center and ground electrodes.

To check and adjust the gap:

1. Use the Right Tool: Obtain a wire-type spark plug gap gauge. Avoid using ramp-style gauges on fine-wire iridium plugs, as they can damage the delicate electrode.
2. Measure: Carefully insert the appropriate wire gauge between the electrodes. There should be a slight drag indicating the correct gap.
3. Adjust (if necessary): If the gap is too small, use the gapping tool's adjustment slot to gently pry the ground electrode outward. If the gap is too wide, gently tap the ground electrode on a clean, hard surface to close it. Never try to bend the center electrode.
4. Re-measure: Double-check the gap after any adjustments.

For your 2017 Chevrolet Malibu, the correct spark plug gap is 0.039 inches (1.0 mm).

Replacement procedure tips

Replacing spark plugs on your 2017 Malibu involves working with a coil-on-plug (COP) ignition system. This means each spark plug has its own ignition coil mounted directly on top of it, eliminating the need for a distributor and spark plug wires.

1. Safety First: Ensure the engine is cool before starting. Disconnect the negative battery terminal to prevent accidental electrical discharge.
2. Access: Depending on your engine (1.5L or 2.0L), you may need to remove engine covers or air intake components to access the ignition coils.
3. Coil-on-Plug Removal: Carefully disconnect the electrical connector from each ignition coil. Then, unbolt the coil (if applicable) and gently twist and pull upward to remove the coil from the spark plug well. Be gentle to avoid damaging the coil boot.
4. Spark Plug Removal: Use a spark plug socket with a rubber insert to carefully remove the old spark plugs. The rubber insert helps to protect the porcelain insulator and hold the plug securely.
5. Anti-Seize Debate: There is ongoing debate about using anti-seize on spark plug threads. For plugs with nickel-plated shells, like the recommended ACDelco plugs, manufacturers generally advise against anti-seize. The nickel plating provides adequate anti-seize properties, and adding more can alter torque readings, potentially leading to overtightening and thread damage. Follow the plug manufacturer's recommendations.
6. Torque Matters: Always use a torque wrench to install new spark plugs to the manufacturer's specified torque: 11 lb-ft (15 Nm). Overtightening can strip cylinder head threads or crack the spark plug insulator, while undertightening can lead to combustion gas leakage and overheating.
7. Dielectric Grease: Apply a small amount of dielectric grease inside the rubber boot of each ignition coil before reinstallation. This helps to seal out moisture, prevents corrosion, and makes future removal easier.
8. Reassembly: Reinstall the ignition coils, ensuring they are properly seated and their electrical connectors are securely attached. Reassemble any removed components.

Known issues

Fortunately, the 2017 Chevrolet Malibu does not have widespread "known issues" related to spark plug breakage, such as the two-piece plug design problems found in some Ford 3-valve engines or ionization-sensing coils like those in certain GM 5.3L engines. As long as you use the correct OEM or equivalent iridium plugs and adhere to the recommended replacement interval and torque specifications, you should experience reliable spark plug performance.

Need plugs replaced? Find a shop on Repairius.