NGK 7401 Spark Plug

NGK Iridium IX Spark Plug Overview

The NGK Iridium IX Spark Plug 7401 is engineered for reliable ignition performance in a wide range of vehicles including Buick, Chevrolet, Ford, and Jeep models. Designed with advanced materials and precise specifications, this spark plug supports efficient combustion and consistent engine operation.

• Iridium center electrode tip for enhanced durability and ignition
• Taper cut ground electrode tip design for improved spark exposure
• Copper core center electrode for optimal conductivity
• Standard ground configuration with nickel ground electrode core
• Non-removable nut electrical terminal type for secure connection
• Pre-gap size of 0.040 inches for precise spark gap
• Tapered seat type and 14mm thread diameter for proper fitment
• Compatible with multiple GM, Ford, Chrysler, and other domestic vehicles

Iridium IX Spark Plug Product Line Details

The Iridium IX Spark Plug line by NGK is designed to provide enhanced ignition performance and longer service life compared to conventional spark plugs. Featuring an iridium center electrode tip, these plugs offer improved wear resistance and stable spark delivery. The 7401 part number belongs to this line, combining iridium technology with a copper core electrode to balance conductivity and durability for secondary ignition systems.

Technical Specifications and Features

This NGK spark plug features a 5/8 inch hex size and a 0.46 inch reach, making it suitable for a variety of ignition systems. The ground electrode uses a taper cut design with a nickel core, which helps maintain a consistent spark and reduces electrode wear. The insulator height is 55.00 mm, and the manufacturer heat range is 4, indicating moderate heat dissipation suitable for many engine types. The non-removable nut terminal ensures a secure electrical connection, minimizing the risk of loosening during operation.

Compatible Vehicles and Applications

• Buick models such as Century, LeSabre, and Regal
• Chevrolet vehicles including Camaro, Impala, and Silverado series
• Ford trucks and SUVs like F-150, Bronco, and Mustang
• Jeep models including Wagoneer and Grand Cherokee
• Other domestic makes such as Cadillac, Chrysler, Dodge, GMC, Lincoln, Mercury, Oldsmobile, Plymouth, Pontiac

Common Issues Addressed by NGK 7401 Spark Plug

• Engine misfires and rough idling
• Reduced fuel efficiency due to incomplete combustion
• Difficulty starting the engine in cold conditions
• Loss of power and acceleration lag
• Excessive exhaust emissions

Installation Notes and Tips

Before installation, verify the spark plug gap is set to the recommended 0.040 inches. Use a torque wrench to tighten the spark plug to the manufacturer’s specifications to avoid damage to the tapered seat. Ensure the ignition system is off and the engine is cool before replacing spark plugs. The 14mm thread diameter and 0.46 inch reach must match the engine’s cylinder head specifications for proper fitment.

Quality Assurance and Warranty

NGK spark plugs are manufactured to meet strict quality standards, ensuring consistent performance and durability. The Iridium IX Spark Plug 7401 undergoes rigorous testing for heat range, electrode wear, and electrical resistance (5000 ohms) to maintain ignition reliability. While specific warranty details may vary, NGK products typically come with manufacturer-backed quality assurance to support long-term use in compatible vehicles.