Denso 3237 Spark Plug

Denso 3237 U-Groove Conventional Spark Plug

Denso 3237 is a conventional spark plug built to OEM quality standards for dependable secondary ignition performance. It uses a copper center electrode core, nickel center and ground electrode tip materials, and a standard ground configuration for consistent spark delivery in the correct heat range.

For drivers searching for a Denso spark plug 3237, an OEM-style ignition tune-up part, or a replacement spark plug for Denso U-Groove Conventional applications, this plug is built around practical service specs rather than unnecessary complexity. It is also a relevant search for Honda Civic spark plug replacement and other vehicle maintenance needs where the correct heat range and thread dimensions matter.

Key Features

• Part number 3237 from Denso U-Groove Conventional
• Manufactured to OEM quality standards
• 5000 ohm resistor for ignition system noise control
• Copper core center electrode for stable heat transfer
• Nickel center and ground electrode tip materials
• Standard ground electrode design with one ground electrode
• Pre-gapped to 1.1 mm
• 14.0 mm thread diameter, 19.0 mm reach, flat seat
• 16.0 mm hex size for proper socket fit
• Manufacturer heat range 14

Product Details

The Denso U-Groove Conventional line focuses on straightforward ignition service with OE-style construction and proven materials. This spark plug uses a copper core to support heat dissipation, while the nickel electrode materials provide a familiar conventional design for routine maintenance. The 5000 ohm resistance specification helps maintain ignition system stability, and the pre-gap size of 1.1 mm supports correct installation out of the box. If you are comparing Denso 3237 against other ignition tune-up parts, the key fitment-critical specs are the 14.0 mm thread diameter, 19.0 mm reach, flat seat, and 16.0 mm hex size.

This part cross-references DENSO Auto Parts KJ14CR11 for the same application.

What It Helps Address

• Rough idle caused by worn spark plug electrodes
• Hard starting from weak or inconsistent spark delivery
• Misfire conditions related to aged ignition components
• Reduced throttle response from degraded plug performance
• Maintenance intervals that call for a conventional replacement spark plug

Installation Notes and Tips

Verify the thread diameter, reach, seat type, and hex size before installation. Use the specified gap setting only if your application requires a different gap than the pre-gap size of 1.1 mm. Inspect the ignition system, plug wires, and coil condition during service, and torque the plug to the vehicle manufacturer’s specification to avoid thread or sealing issues. Search terms such as Denso 3237 spark plug, Honda Civic ignition service, and OEM replacement spark plug are commonly used when confirming the correct part.

Quality Assurance

Denso manufactures this spark plug to OEM quality standards, with conventional materials and dimensions selected for consistent service performance. For buyers comparing Denso 3237 with other ignition parts, the U-Groove Conventional line provides a straightforward OE-style replacement option.