CAT 371-3974 Common Rail Fuel Injector

Product Overview

The CAT 371-3974 Common Rail Fuel Injector is a Genuine Caterpillar OEM fuel injector engineered to deliver the precise amount of high-pressure fuel into the combustion chamber at the correct time for optimum engine performance. Designed to Caterpillar’s exact OEM specifications, this common rail injector supports efficient combustion, improved fuel economy, reduced emissions, and dependable engine operation in demanding applications.

The 371-3974 Common Rail Fuel Injector is identified by Caterpillar as a Commercial Vehicle Common Rail Injector – Low Power Fuel Injector. It is manufactured using precision-machined internal components to provide accurate fuel metering, consistent spray characteristics, and reliable performance under high-pressure operating conditions. As a Genuine Caterpillar OEM replacement part, it restores factory fuel system performance while ensuring proper fit, durability, and long service life.

Key Features

• Genuine Caterpillar OEM Common Rail Fuel Injector
• Part Number: 371-3974
• Commercial Vehicle Common Rail Injector – Low Power Fuel Injector
• Delivers high-pressure fuel directly into the engine combustion chamber
• Provides precise fuel metering for efficient combustion
• Supports improved fuel economy and reduced exhaust emissions
• Precision-engineered internal nozzle and injector components
• Designed for high-pressure common rail fuel systems
• OEM-quality construction for long service life
• Direct OEM replacement manufactured to Caterpillar specifications

Technical Specifications

Note: Caterpillar has not published additional injector flow rate, nozzle specifications, operating pressure, or electrical characteristics for the CAT 371-3974 Common Rail Fuel Injector beyond the information listed above.

Application Information

The CAT 371-3974 Common Rail Fuel Injector is used in Caterpillar high-pressure common rail diesel fuel systems to deliver the correct quantity of fuel into each engine cylinder at precisely controlled timing and pressure. Accurate fuel delivery helps optimize combustion efficiency, engine performance, fuel economy, and emissions while supporting reliable engine operation.

Manufactured to Caterpillar OEM standards, the injector is designed to withstand:

• High fuel pressures
• Elevated engine temperatures
• Continuous duty cycles
• Vibration
• Harsh operating environments

These characteristics help ensure dependable fuel delivery and long-term engine reliability.

Compatible Caterpillar Equipment

The CAT 371-3974 Common Rail Fuel Injector is compatible with a wide range of Caterpillar equipment, including:

Engines

• C7.1 Industrial Engine
• 3512B Generator Set Engine

Generator Sets

• 3512B

Excavators

• 320
• 320D
• 320D GC
• 320D L
• 320D2 FM
• 323
• 323 GC
• 323 GX
• 323D L
• 323D2 L
• 323GC
• 326
• 326 GC
• 326D2
• 326D2 L
• 326GC
• 329D2 L
• 330
• 330 GC
• 330D2
• 330D2 L
• 333 GC

Wheel Loaders

• 924
• 924K
• 926
• 930
• 930K
• 938
• 938K

Track Loaders

• 953
• 953K

Track-Type Tractors

• D4
• D5
• D5R2
• D6K
• D6K2
• D6N

Motor Graders

• 120
• 140 GC

Soil & Vibratory Compactors

• CS12
• CS14
• CS16
• CS19
• CS20
• CS56B
• CS68B
• CS74B
• CS78B
• CS79B
• CP12
• CP14
• CP16
• CP17
• CP56B
• CP68B
• CP74B
• CP76B

Asphalt Pavers

• AP600
• AP600F
• AP655
• AP655F
• AP655F L

Material Handlers

• MH3032
• M320
• M320D2
• M322D2
• M322D2 MH
• M324D2 MH

Wheel Skidders

• 525D

Pipelayers

• PL61

Compatibility should always be verified using the machine’s:

• Product Identification Number (PIN)
• Serial Number
• Arrangement Number
• Existing injector part number

Verification through Caterpillar Parts information or an authorized Cat dealer is recommended before ordering.

Additional Compatibility Information

The 371-3974 Common Rail Fuel Injector is a configuration-specific fuel system component. Before installation, verify:

• Machine model
• Product Identification Number (PIN)
• Engine serial number
• Existing injector part number
• Engine arrangement
• Fuel system configuration
• Injector calibration requirements
• Equipment arrangement number

Any modifications to the original equipment configuration may affect compatibility. Confirmation through Caterpillar Parts information or an authorized Cat dealer is recommended before installation.

Benefits

Installing a genuine CAT 371-3974 Common Rail Fuel Injector helps:

• Restore precise high-pressure fuel delivery
• Improve combustion efficiency and engine performance
• Support fuel economy and reduced emissions
• Maintain reliable engine starting and smooth operation
• Reduce downtime caused by worn or malfunctioning injectors
• Simplify maintenance with a direct OEM replacement
• Preserve factory fuel system performance
• Deliver OEM-quality fit, durability, and long-lasting reliability in demanding operating environments.