Denso 3139 Spark Plug

Reliable Ignition Performance for Select Vehicles

The Denso 3139 spark plug from the U-Groove Conventional line offers dependable ignition for a range of vehicles including Toyota Camry, Lexus RX330, and Mercedes-Benz C230. Designed with precision materials and a unique U-groove ground electrode tip, this spark plug supports efficient combustion and consistent engine performance.

• U-groove ground electrode tip design for improved ignition
• Nickel ground electrode and center electrode tip for durability
• Copper core center electrode for enhanced conductivity
• Standard ground configuration with a single ground electrode
• Flat seat type with 14mm thread diameter and 19mm reach
• Pre-gap size of 1.1 mm optimized for specified engine requirements
• Hex size of 16.0 mm for standard installation tools
• Manufacturer heat range rating of 20 for balanced heat dissipation
• Resistance of 5000 ohms to reduce electrical noise interference

About the Denso U-Groove Conventional Spark Plug Line

The U-Groove Conventional spark plug line by Denso features a distinctive U-shaped groove on the ground electrode tip. This design enhances the spark exposure to the air-fuel mixture, promoting more complete combustion. The conventional construction with nickel and copper materials ensures reliable performance and longevity across various engine types. The Denso 3139 spark plug is part of this line, combining traditional durability with improved ignition characteristics.

Technical Details and Compatibility

The Denso 3139 spark plug is engineered with a copper core center electrode for excellent thermal conductivity, paired with nickel tips on both the center and ground electrodes to resist wear. The single ground electrode with a U-groove tip design supports stable spark generation. With a flat seat and 14mm thread diameter, it fits securely in compatible engines. The 1.1 mm pre-gap size and heat range 20 rating are tailored to maintain optimal combustion temperatures and prevent fouling or overheating.

Compatible Vehicles and Applications

• Chrysler Crossfire and Sebring
• Lexus RX330, ES300, GS400, and LS430
• Mercedes-Benz C230, CLK55 AMG, and SLK55 AMG
• Toyota Camry, Corolla, Highlander, and 4Runner
• Volvo S60, S80, and XC90

Common Issues Addressed by Denso 3139 Spark Plug

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

Installation Notes and Tips

Before installation, verify the spark plug gap is set to 1.1 mm as specified. Use a 16 mm socket wrench for proper tightening to avoid damage to the flat seat. Ensure the thread diameter of 14 mm and reach of 19 mm match the engine specifications. It is recommended to replace spark plugs in sets to maintain consistent engine performance. Avoid over-tightening to prevent thread damage.

Quality Assurance and Warranty

Denso spark plugs, including the 3139 model, are manufactured to meet strict quality standards for durability and performance. The use of nickel and copper materials ensures resistance to electrode wear and thermal stress. While specific warranty details may vary, Denso products typically come with manufacturer-backed quality assurance to support reliable operation in compatible vehicles.