NGK 4004 Spark Plug

NGK Standard Spark Plug 4004 Overview

The NGK Standard Spark Plug 4004 is built for drivers who need a direct-replacement ignition component with OE-style construction and consistent firing performance. As part of NGK’s Standard Spark Plug line, this plug uses a copper core center electrode, nickel tip materials, and a standard ground configuration for dependable everyday operation.

With a 10,000 ohm resistor, .028 pre-gap, 14 mm thread diameter, .375 reach, and flat seat design, the NGK 4004 is engineered for applications that call for a conventional spark plug specification. It is a practical choice for routine maintenance on vehicles such as Honda Civic and Toyota Corolla applications where the correct heat range and terminal style matter.

Key Features

• NGK Standard Spark Plug line for OE-style replacement service
• Part number 4004, also identified as BMR4A SOLID
• Copper center electrode core for stable ignition transfer
• Nickel center and ground electrode tip materials
• 10,000 ohm resistor for ignition noise suppression
• Standard ground electrode design with one ground electrode
• .028 pre-gap, 14 mm thread diameter, .375 reach, and flat seat
• Non-removable nut terminal and 3/4 hex size

Product Details

NGK has long supplied spark plugs for domestic and import vehicles, and the Standard Spark Plug line focuses on straightforward replacement fitment and original-equipment-style specifications. The 4004 spark plug is built around a copper core center electrode and nickel electrode tips, which are common in conventional ignition service where reliable spark delivery and consistent combustion are priorities. The manufacturer heat range 4 specification helps identify the plug for the correct engine application, while the standard ground configuration supports predictable operation in the intended cylinder head design.

For long-tail searches, this spark plug is commonly researched as an NGK 4004 spark plug for Honda Civic and Toyota Corolla ignition service, as well as a standard replacement spark plug for import vehicle maintenance. This part cross-references AMS Automotive 4004 for the same application.

Common Issues This Part Can Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle from inconsistent spark delivery
• Misfire conditions related to aged ignition components
• Reduced fuel efficiency from degraded plug performance
• Weak acceleration caused by improper combustion

Installation Notes and Tips

Verify the engine’s required thread diameter, reach, seat type, heat range, and terminal style before installation. The NGK 4004 uses a flat seat, 14 mm thread, .375 reach, and non-removable nut terminal, so matching the original specification is important for proper sealing and ignition performance. Check the gap against the engine’s service specification before installing, even though the plug is supplied with a .028 pre-gap.

For Honda Civic, Toyota Corolla, and other import vehicle applications, confirm the exact engine code and ignition requirements before replacing the spark plug. Use proper torque procedures and inspect the ignition system for worn wires, coils, or deposits that could affect plug life.

Quality Assurance

NGK is a major OE supplier and manufacturer of spark plugs for domestic and import vehicles in North America, with decades of automotive ignition experience. The 4004 reflects that OE-focused approach through conventional materials, standard dimensions, and application-specific engineering for dependable service.