Thermostat 15-07000031

• Thermostat 15-07000031

Thermostat 15-07000031

This thermostat regulates coolant flow based on engine temperature.

It is located in the thermostat housing or water passage; terminals in the open or closed position can cause the operating temperature to be too low or the engine to overheat.

Component classification: Thermostat / Coolant control valve

System function: Temperature control in the cooling circuit

Compatible Manufacturers: MerCruiser / OMC / Parsun / Honda / Tohatsu

Compatible models: MURENA EFI 40XSR/70

Part Numbers:

• MerCruiser: 27-62386, 62981, 66850, 75692, 75692B, 825212, 825212001, 825212T02, 833072, 833072002, 833072003, 833072004, 855676003, 8M0117413, 8M6010302
• OMC: 0508620, 5005440
• Parsun: F15-07000031
• Honda: 19300-881-741, 19300-921-003, 19300-ZW9-003
• Tohatsu: HZW9-19300-003

FAQ

What exactly is the purpose/function of this component?
The thermostat regulates coolant flow based on engine temperature and brings the engine to operating temperature in a controlled manner. It thus affects warm-up, thermal performance, and corrosion behavior.

How can you tell if it’s defective? What are the typical symptoms?
Typical symptoms include an engine that is too cold or too hot, a fluctuating temperature gauge reading, or a delayed rise in temperature. If the thermostat sticks in the open or closed position, the entire cooling system is affected.

How do you inspect or test the component?
Once removed, check the opening temperature and travel in a temperature-controlled water bath equipped with a thermometer. Additionally, inspect the seating surface, corrosion, spring condition, and sealing surfaces of the thermostat and its housing.

When should it be replaced?
The thermostat should be replaced if the opening temperature is incorrect, if it responds sluggishly, or if there is corrosion or mechanical damage. As part of major cooling system maintenance, a preventive replacement is often cost-effective.

How do you check compatibility?
Compare the OEM part number, opening temperature, overall height, diameter, bypass design, and sealing concept. The thermostat housing, mounting clips, and any additional valves must also be compatible.