Can a Stuck Thermostat Cause Engine Overheating in the Hilux?

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Can a Stuck Thermostat Cause Engine Overheating in the Hilux?

A stuck thermostat can prevent coolant from circulating properly. Has your Hilux ever overheated due to a faulty thermostat? How did you fix it?

Lubaba asked on 11 Feb 2025 11:38:17 am

1 Answer

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Car Mechanic Expert - on 11 Feb 2025 11:44:34 am

Yes, a stuck thermostat can cause severe overheating by blocking coolant flow, leading to engine damage. Some Hilux owners have experienced this issue, especially after high mileage 100,000+ km o r due to poor coolant maintenance.
Fixing the Issue:

Immediate Action: If overheating occurs, turn off the engine, let it cool, and check coolant levels.
Inspection: Look for coolant leaks, check if the upper radiator hose is cold indicating no coolant flow, and monitor temperature gauge fluctuations.
Thermostat Replacement: If diagnosed as faulty, replacing the thermostat with an OEM Toyota part ensures proper operation. Its also recommended to flush the cooling system and use high-quality coolant to prevent future issues.

Ignoring a stuck thermostat can cause head gasket failure, so timely replacement is crucial.