Autolite 3924 Spark Plug

Autolite Copper Resistor Spark Plug Overview

The Autolite Copper Resistor Spark Plug 3924 is engineered to deliver reliable ignition performance for a wide range of vehicles including Acura, Ford, Toyota, and BMW models. Designed with a copper core and resistor technology, this spark plug supports efficient combustion and reduces electrical interference.

• Resistance rating of 4000 ohms for noise suppression
• Tapered ground electrode tip made of nickel for durability
• Copper center electrode core with nickel tip for optimal conductivity
• Mid projection ceramic insulator for enhanced heat dissipation
• Flat seat type with 0.750 inch reach and 14.0 mm thread diameter
• Pre-gap size of 0.044 inches (1.10 mm) for precise spark delivery
• Hex size 5/8 inch (16 mm) for standard installation tools

Detailed Product Features and Design

The Autolite Copper Resistor Spark Plug 3924 features a copper core center electrode that improves thermal conductivity, helping to maintain optimal operating temperatures. The nickel ground electrode with a tapered tip design enhances spark efficiency and electrode longevity. Its resistor type construction, rated at 4000 ohms, minimizes radio frequency interference, ensuring smooth operation of onboard electronics. The ceramic insulator with mid projection design provides excellent insulation and heat resistance, supporting consistent ignition performance across various driving conditions.

About the Copper Resistor Spark Plug Product Line

The Copper Resistor Spark Plug line by Autolite is designed to combine traditional copper core technology with resistor features to reduce electrical noise. This product line is suitable for many domestic and import vehicles, offering a balance of performance and durability. The 3924 part number is a representative model within this line, engineered to meet OEM specifications for ignition components.

Compatible Vehicles and Applications

• Compatible with Acura, Ford, Toyota, BMW, Honda, and many other makes
• Fits models such as 4Runner, Camry, Civic, 325i, and Grand Cherokee
• Ideal for vehicles requiring a 14 mm thread diameter and 0.750 inch reach spark plug
• Suitable for secondary ignition system replacement and maintenance

Common Issues Addressed by This Spark Plug

• Misfires caused by worn or fouled spark plugs
• Ignition noise interference affecting electronic systems
• Poor fuel efficiency due to inconsistent spark delivery
• Engine hesitation or rough idling
• Difficulty starting the engine in cold conditions

Installation Notes and Tips

Ensure the spark plug gap is set to the specified 0.044 inches (1.10 mm) before installation. Use a 5/8 inch (16 mm) socket wrench for proper tightening. Avoid over-tightening to prevent damage to the flat seat and threads. It is recommended to replace spark plugs in sets to maintain balanced engine performance. Always consult the vehicle’s service manual for torque specifications and installation procedures.

Quality Assurance and Warranty

Autolite spark plugs are manufactured to meet or exceed OEM standards for ignition components. The Copper Resistor Spark Plug 3924 undergoes rigorous quality control to ensure durability and consistent performance. While specific warranty details are not provided, Autolite products typically come with manufacturer-backed quality assurance to support reliable operation.