Product Introduction:

The 3335550 and 4973373 are Cummins thermostat part numbers. Both are used in Cummins diesel engines to regulate coolant temperature and maintain optimal operating conditions. The 3335550 is primarily associated with ISX and QSX engines , while the 4973373 is commonly referenced for N14 engines .

1. Installation Location
The thermostat is installed in the engine's cooling system housing, typically located at the front of the engine block near the coolant outlet. It is positioned between the engine and the radiator, controlling the flow of coolant based on temperature.

2. Function
The thermostat regulates engine coolant temperature by opening and closing a valve. When the engine is cold, the thermostat remains closed, allowing the engine to warm up quickly. Once the coolant reaches the rated opening temperature of 180°F (82°C), the valve opens to allow coolant to flow through the radiator, preventing overheating .

3. Maintenance and Service
The thermostat is a wear item that should be replaced if the engine shows signs of overheating, slow warm-up, or temperature fluctuations. It is not user-serviceable internally. When replacing, use an identical unit and a new seal or gasket. Always ensure the engine is cool and the cooling system is depressurized before removal.

4. Important Notes
Always verify the part number matches the original component before installation. These thermostats are cross-compatible with several Cummins part numbers, including 2882757, 4952204, and 4318197 . Confirm compatibility with the specific engine model (M11, N14, ISX, QSX) before purchase