2014 Isuzu NQR Spark Plug Type, Gap & Torque

Quick reference

Why the right plug matters

The spark plug is a small but essential part of your Isuzu NQR's ignition system. It creates the spark that ignites the air-fuel mixture in the combustion chamber. Using the correct spark plug is crucial for optimal engine performance, fuel economy, and longevity.

Heat Range

Spark plugs are designed with a specific heat range. This refers to the plug's ability to dissipate heat from the combustion chamber. A plug that is too "hot" can lead to pre-ignition and engine damage, while a plug that is too "cold" can foul and cause misfires.

Electrode Metal

The electrode is the part of the spark plug that the spark jumps from. The material of the electrode affects the plug's performance and lifespan.

• Iridium: Iridium is a precious metal that is extremely hard and has a high melting point. Iridium spark plugs offer the best performance and longest lifespan, typically lasting up to 100,000 miles.
• Platinum: Platinum is another precious metal that is used in high-performance spark plugs. Platinum plugs offer excellent performance and a long lifespan, but they are not as durable as iridium plugs.
• Copper: Copper is a good conductor of electricity, but it has a lower melting point and is not as durable as iridium or platinum. Copper spark plugs are the most affordable option, but they have the shortest lifespan and need to be replaced more frequently.

How to gap a spark plug

The gap is the distance between the center electrode and the ground electrode of the spark plug. This distance must be set to the manufacturer's specifications for proper ignition.

To gap a spark plug, you will need a spark plug gapping tool. These tools are inexpensive and can be purchased at any auto parts store.

1. Insert the gapping tool into the gap between the electrodes.
2. Gently bend the ground electrode until the correct gap is achieved.
3. Be careful not to damage the center electrode or the porcelain insulator.

Replacement procedure tips

The 2014 Isuzu NQR with the 6.0L V8 engine features a coil-on-plug ignition system. This means that each spark plug has its own ignition coil. This design provides a hotter, more efficient spark, but it also requires a few extra steps when changing the spark plugs.

• Coil-on-plug removal: To access the spark plugs, you will first need to remove the ignition coils. The coils are held in place by a single bolt. Once the bolt is removed, the coil can be gently twisted and pulled off of the spark plug.

• Anti-seize debate: There is some debate among technicians about whether or not to use anti-seize compound on spark plug threads. Some technicians believe that it is necessary to prevent the plugs from seizing in the cylinder head, while others believe that it can cause the plugs to be over-torqued.

  The best course of action is to follow the manufacturer's recommendations. In the case of the 2014 Isuzu NQR, the service manual does not recommend using anti-seize compound.

• Dielectric grease on boots: It is a good idea to apply a small amount of dielectric grease to the inside of the spark plug boots before reinstalling them. This will help to prevent the boots from sticking to the spark plugs and will also help to keep out moisture.

Known issues

There are no known issues with the spark plugs or ignition system on the 2014 Isuzu NQR.

Need plugs replaced? Find a shop on Repairius.