Do it yourself
Frequently asked questions about cars and motorcycles
Car tutorial (Do it yourself) Motorcycle tutorial (Do it yourself) Frequently Asked Questions

How does a car's thermostat work?

Model: (Various brands) Various
Part: Thermostat

This video shows us how the physical principle of the thermostat works, which is an example of a heat transformer into mechanical motion. When cold, the wax (a wax based on engineered paraffins) inside the capsule is solid and contracted. A spring keeps the piston retracted and the valve closed. This blocks the flow of liquid to the radiator, allowing the engine to heat up quickly. When hot, when the liquid reaches the specific opening temperature of the thermostat, the wax melts and expands, violently pushing the piston inside the capsule. The piston, in turn, acts against the force of the spring and pushes out the disc, opening the valve. If the liquid temperature drops below the threshold, the wax solidifies and contracts; the spring becomes stronger than the contracted wax and closes the valve, pushing the piston back.

Posted on 22 January 2026 by ScegliAuto

Video tutorial

Related tutorials

How to Remove the Thermostat on a Car
How to Remove the Thermostat on a Car
(Various brands) Various If the thermostat in your car is faulty, it needs replacing; follow this procedure. Disconnect the hoses leading to the thermostat. Unscrew the bolts…
Replacing the Car Thermostat
Replacing the Car Thermostat
(Various brands) Various Is the thermostat in your car damaged? Let’s see how to remove the part. Lift the front cover bonnet and uncover the engine from its soundproofing pa…
Removing the Thermostat Valve from a Car
Removing the Thermostat Valve from a Car
(Various brands) Various In this video tutorial, you will learn how to remove the thermostat valve from a car: the process may vary from vehicle to vehicle, but we will cover…

Other guides you may be interested in

    Frequently Asked Questions

    • Vari - Why doesn't the radiator fan turn off? Read answer

How to Open a Stuck Boot on the Peugeot 407?

On the Peugeot 407, the boot may become stuck, possibly due to a problem with the control button or the lock actuator. In such cases, you can perform an emergency opening by following the simple procedure shown in this tutorial. First, open the rear doors, then lower the seat back by operating the release lever. Next, go inside the boot, locate the lock, and manually operate it using a flathead screwdriver. The boot will then be free to open.

Watch the video!


by ScegliAuto

More videos