180℉ Thermostat 3974823 5292708 for Cummins 5.9L ISB 4.5L QSB B-Series Engines
$35.19
Sale price
$35.19
Regular price
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SKU:
ZZ3F01217
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180℉ Thermostat 3974823 5292708 for Cummins 5.9L ISB 4.5L QSB B-Series Engines
$35.19
In Stock
$35.19
Sale price
$35.19
Regular price
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Compatible Models
We do our best to list all compatible models. Although this may be the part you need, your exact model may not appear below.
Compatible equipment / model
180°F Thermostat for Cummins 5.9L ISB, 4.5L QSB, B-Series Engines
This 180°F thermostat, with cross-reference numbers 3974823 and 5292708, is a direct replacement for Cummins 5.9L ISB, 4.5L QSB, and B-Series engines, ensuring proper engine operating temperature for efficient combustion and heating performance.
Overview
This 180°F thermostat controls coolant flow to keep your Cummins 5.9L ISB, 4.5L QSB, or B-Series engine at its optimal operating temperature. It opens at 180°F to allow coolant circulation once the engine warms up, supporting efficient fuel burn, faster cab heat, and reduced engine wear. This thermostat is built for engines that specify a 180°F opening temperature, matching the original 3974823 and 5292708 part numbers.
Built For Performance
- Precise 180°F opening temperature to match OEM specifications
- Cross-references OEM numbers 3974823 and 5292708
- Engineered for Cummins 5.9L ISB, 4.5L QSB, and B-Series applications
- Constructed with durable metal and heat-resistant components for long service life
- Ensures consistent coolant flow for stable engine temperatures
Fits These Machines
- for Cummins 5.9L ISB
- for Cummins 4.5L QSB
- for Cummins B-Series engines
On-The-Job Use
- Ideal for replacing a stuck-open or stuck-closed thermostat during routine cooling system maintenance
- Used in trucks, buses, agricultural equipment, and industrial machinery powered by these Cummins engines
- Helps restore proper warm-up time and heater output in cold climates
Specs At A Glance
| Opening Temperature | 180°F (82°C) |
| Part Number(s) | 3974823, 5292708 |
| Engine Family | for Cummins 5.9L ISB, 4.5L QSB, B-Series |
Good To Know
Q: What does a 180°F thermostat do? A: It opens at 180°F to let coolant flow through the radiator, preventing engine overheating while allowing quick warm-up. This helps maintain proper combustion temperatures and reduces engine wear.
Q: How do I know if this thermostat fits my engine? A: Check your engine's serial number and existing part number against 3974823 or 5292708. Always confirm the thermostat diameter and opening temperature before installing.
Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.