3971420
Thermostat
Cummins®

Name: 3971420 Cummins | Thermostat
Brand: Cummins
SKU: 3971420
Price: 23.95 USD
Availability: Discontinued
Rating: 5 (1 reviews)

DISCONTINUED

Genuine OEM Part

This truck part is made by Cummins®. We guarantee that all of our parts are from the OEM (original equipment manufacturer), ensuring a proper fit and quality manufacturing.

Manufacturer Warranty*

We honor the warranty provided by the original equipment manufacturer.

DESCRIPTION

The Cummins 3971420 Thermostat is a component designed for use in commercial trucks. It is integral to the engine cooling system, ensuring that the engine operates within the optimal temperature range. This thermostat helps in maintaining engine efficiency, performance, and longevity by regulating the flow of coolant through the engine ².

Basic Concepts of a Thermostat

A thermostat is a device that senses the temperature of a system and controls the flow of fluid or air to maintain the system at a desired setpoint. In the context of an engine cooling system, the thermostat regulates the flow of coolant between the engine and the radiator. When the engine is cold, the thermostat remains closed, preventing coolant flow and allowing the engine to warm up quickly. As the engine temperature rises, the thermostat opens, allowing coolant to circulate and cool the engine ¹.

Purpose of the Cummins 3971420 Thermostat

The Cummins 3971420 Thermostat plays a role in maintaining optimal engine temperature in commercial trucks by regulating the flow of coolant. It ensures that the engine reaches its operating temperature quickly and maintains this temperature under varying conditions. This regulation is vital for engine efficiency, as it ensures that the engine operates within its designed temperature range, reducing wear and improving performance ².

Key Features

The Cummins 3971420 Thermostat is characterized by several distinctive features. Its design includes a robust housing that can withstand high temperatures and pressures typical in commercial truck engines. The thermostat is made from durable materials that ensure longevity and reliable performance. Additionally, it incorporates precise temperature control mechanisms that allow for accurate regulation of coolant flow ².

Benefits of Using the Cummins 3971420 Thermostat

Installing the Cummins 3971420 Thermostat in commercial trucks offers several advantages. It contributes to improved engine performance by ensuring that the engine operates at optimal temperatures. This optimal operation leads to enhanced fuel efficiency and reduced emissions. Furthermore, the thermostat’s durable construction and reliable performance contribute to the overall longevity of the engine ².

Installation Process

Proper installation of the Cummins 3971420 Thermostat involves several steps. First, the old thermostat should be removed, and the housing should be cleaned to ensure a proper seal. The new thermostat should be installed with the spring side facing the engine. It is important to use the correct gasket and to ensure that all connections are tight to prevent leaks. Tools required may include a wrench, gasket scraper, and a torque wrench ².

Troubleshooting Common Issues

Frequent problems associated with thermostats include failure to open or close properly, leading to overheating or insufficient engine warm-up. Diagnosing these issues involves checking the thermostat’s operation and ensuring that it opens at the correct temperature. Potential solutions may include replacing the thermostat or cleaning the housing to remove any debris that may be affecting its operation ¹.

Maintenance Tips

Regular maintenance practices can ensure the longevity and efficient operation of the Cummins 3971420 Thermostat. This includes periodic inspection of the thermostat and housing for signs of wear or damage. It is also important to ensure that the cooling system is free of contaminants and that the coolant is at the proper level and concentration. Following the manufacturer’s recommended service intervals for thermostat replacement can also contribute to maintaining optimal engine performance ².

Cummins Overview

Cummins Inc. is a global power leader that designs, manufactures, and distributes engines, filtration, and power generation products. Founded in 1919, Cummins has a long history of innovation and quality in the commercial truck industry. The company offers a wide range of products, including engines, powertrains, and aftermarket parts, and is known for its commitment to customer satisfaction and technological advancement ².

Role of Part 3971420 Thermostat in Engine Systems

The thermostat, identified by part number 3971420, is an integral component in maintaining the optimal operating temperature of an engine. It is strategically positioned between the engine and the radiator within the cooling system.

When the engine is cold, the thermostat remains closed, preventing coolant from flowing to the radiator. This allows the engine to warm up quickly. As the engine temperature rises, the thermostat gradually opens, allowing coolant to circulate through the radiator where it is cooled before returning to the engine. This continuous cycle ensures that the engine operates within its designed temperature range ².

The thermostat interacts with several key components within the engine system:

Water Pump: The water pump circulates coolant through the engine and to the thermostat. As the thermostat opens, the water pump facilitates the flow of coolant to the radiator.
Radiator: Once the thermostat opens, coolant flows into the radiator where it is cooled by air passing through the fins. The cooled coolant then returns to the engine to absorb more heat.
Coolant Passages: These are the pathways within the engine block and cylinder head that allow coolant to flow near critical components, absorbing heat and transferring it to the coolant.
Temperature Sensor: This sensor monitors the engine temperature and sends data to the engine control unit (ECU). The ECU uses this information to make adjustments, such as activating the radiator fan or adjusting the fuel mixture.
Radiator Fan: In some systems, the radiator fan is controlled by the ECU based on temperature sensor readings. When the engine temperature rises, the fan may activate to increase airflow through the radiator, enhancing cooling efficiency ².

Conclusion

The Cummins 3971420 Thermostat is a critical component in the engine cooling system of commercial trucks. By regulating the flow of coolant, it ensures that the engine operates within the optimal temperature range, contributing to engine efficiency, performance, and longevity. Proper installation, regular maintenance, and timely replacement of this part are essential for maintaining the overall health and performance of the engine.

Nigel Calder, Diesel Engine Care and Repair, The McGraw-Hill Companies, 2007.
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Giancarlo Genta and Lorenzo Morello, The Automotive Chassis Volume 1 Components Design Mechanical Engineering Series 2nd Edition, Springer, 2019.
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SPECIFICATIONS

Package Dimensions

3.4 x 3.3 x 2.5 in

Weight

0.27 lbs

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* This information is provided as is and may be out of date. Please contact us or the manufacturer to verify warranty coverage.
* Variable geometry turbocharger and electronic actuator repairs are not eligible to be claimed as over-the-counter under New or ReCon parts warranty for parts installed after October 1, 2018.
* Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF), Selective Catalyst Reduction (SCR) catalyst, and Electronic Control Module (ECM) repairs are not eligible to be claimed as over-the-counter under New or ReCon parts warranty for parts installed after January 1, 2020.
* These restrictions are only applicable to New parts and ReCon parts coverages for the components listed above sold to a customer in the US or Canada. All other coverages are excluded. All other regions are excluded.

3971420 Thermostat Cummins®