Engine Thermostats and Thermostat Housings

What Does an Engine Thermostat Do?

The engine thermostat is a temperature-sensitive valve that controls the flow of coolant between the engine and radiator. When the engine is cold, the thermostat stays closed, allowing coolant to circulate only within the engine to bring it up to operating temperature quickly. Once the coolant reaches the thermostat opening temperature - typically 80 to 95 degrees C - it opens and allows hot coolant to flow to the radiator for cooling. This cycle maintains the engine within its optimal temperature range for fuel efficiency and emissions.

Symptoms of a Failing Thermostat

Thermostats fail in two ways - stuck open or stuck closed - and each causes different problems. Common symptoms include:

• Engine overheating - thermostat stuck closed trapping heat in the engine
• Engine never reaching normal operating temperature - thermostat stuck open allowing constant coolant flow
• Temperature gauge reading higher or lower than normal
• Heater not producing adequate heat in winter - engine running too cool
• Poor fuel economy - engine running below optimal temperature
• Coolant leaking from the thermostat housing or gasket

Fitment and Technical Accuracy

Thermostats vary in opening temperature, housing design, and gasket type between makes, models, and engine variants. Fitting a thermostat with the wrong opening temperature will cause the engine to run too hot or too cool. Every thermostat in our range is matched to OEM temperature specifications. Use the Vehicle Part Finder to confirm the correct thermostat for your engine before ordering.

Why Buy From SensorGal?

SensorGal is a 100% Australian owned family business stocking aftermarket OEM replacement thermostats and thermostat housing assemblies for Toyota, Holden, Ford, Mitsubishi, Nissan, Hyundai, Kia, BMW, Mazda, Subaru, Mercedes-Benz and Suzuki. Orders placed before 12 noon are dispatched same day from our Cranbourne VIC warehouse via express post. All parts carry a 1-Year Australian warranty and our no-fuss returns policy.