Thermostat replacement from $388

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Average rating for Thermostat replacement


4.6 • based on 68 reviews of 60 businesses

Thermostat replacement

How much does a thermostat replacement cost?


You might think your engine thermostat’s only purpose is to prevent overheating, but that’s not all it does.

Your engine thermostat also restricts coolant flow on warmup to create heat inside your car sooner, and to get the engine into the best operating range for proper emissions.

Over time and by constantly opening and closing during operation, the thermostat can become weak, get stuck open or closed, or become restricted by corrosion buildup.

You can expect thermostat replacement to be between $150 and $250 for most vehicles, although some are exponentially more due to vehicle design. 

What is a thermostat?

A thermostat is a small, mechanical valve inside the cooling system. When the thermostat is below operating temperature, a spring keeps it closed.

It prevents engine coolant from flowing through the coolant hoses to the radiator, keeping coolant inside the engine until it warms up.

As the engine temperature increases to the thermostat’s operating temperature, a small charge of wax inside the valve expands and opens the valve, and the water pump can circulate the engine’s coolant throughout the cooling system

As the heat dissipates, the wax contracts and the valve closes. This cycle repeats over and over again until the engine is shut down and cools off. 

Symptoms that a thermostat replacement is required

  • Your engine doesn’t get up to operating temperature.
  • No heat coming through your dash vents.
  • The temperature gauge spikes to full hot while running, and your engine overheats.
  • The Check Engine light illuminates for coolant temperature codes.
Thermostat replacement costs

How is a thermostat replacement performed?

  • The cooling system is drained and the technician locates the thermostat, typically on the engine by the upper radiator hose.
  • The thermostat housing is unbolted from the engine.
  • The failed thermostat is removed and a new one is installed in its place, noting the exact orientation of the old part.
  • The cooling system is refilled with coolant and the engine is run to operating temperature to confirm the repair.

Tips to remember

  • When removed from your car, the thermostat can be tested by putting it in hot water and monitoring the temperature at which it opens with a thermometer.
  • A thermostat installed backwards may still function, albeit less effectively.
  • A new gasket should always be used when re-installing the thermostat housing.

How important is a thermostat replacement?

If the thermostat has stuck closed, it could spell an overheating condition that will damage your engine and cooling system.

Along with that comes expensive engine repairs. A thermostat stuck open can cause your engine not to achieve operating temperature, meaning more fuel consumption, poor emissions, and lack of heat inside your car.

If you’ve read this far, you obviously care about your car. A lot. So next time you need a service, repair or inspection, visit

We let you search and book from over 1600 qualified mechanics, who eat car troubles for breakfast.

Image Credit: Christopher Blizzard