How To Test Thermostat On Car – The Best Answer As Expert

The thermostat housing is one of the most comfortable pieces of equipment of all modern cars. It makes all passengers in the automobile feel more comfortable, especially in the hot and humid climate.

These measures can help your car’s air conditioning system operate more effectively and consistently. Particularly, how to test thermostat on car? 

Scroll down to get the answer.

What Is A Car Thermostat?

how to test thermostat on car
A Car Thermostat

The thermostat is crucial in keeping the engine’s operating temperature safe. It is an extremely small component of the car’s engine cooling system.

However, this particular element impacts the temperature stability of the engine, which helps conserve fuel and extend the life and durability of the car.

The car thermostat housing is often positioned on the piping that connects the engine to the radiator hose.

This component is utilized to keep the engine’s coolant temperature steady by managing the amount of liquid moving through the cooler.

The thermostatic valve’s primary responsibility is to manage engine overheating and temperature.

To maintain steady and effective engine functioning, the spring inside the thermostatic valve will specifically assist in controlling the flow of cooling water from the engine block into the radiator hose.

Many individuals are interested in this valve’s impact, which is the task.

Thermostatic valves are similar to gates in that they may open (allow) or close (disallow) the coolant flow from the engine to the radiator.

It promotes the engine’s and equipment’s safest and most stable functioning.

How Does A Car Thermostat Work?

Before learning about how to test thermostat car, you should know how a car thermostat works.

The thermostatic valve comprises a main valve, secondary valve, intake cylinder, seal, and spring. Each detail undertakes certain tasks, specifically:

  • Main valve: This part helps control the flow of water, responsible for cooling inside the engine. When the temperature of the cooling system increases, the main valve will gradually open and discharge more water, helping the radiator to be cooled.
  • Secondary valve: Besides the main valve, the secondary valve also plays an extremely important role. When this valve is open, the amount of cooling water passing through the radiator will be circulated in a closed cycle. When the coolant temperature rises, this valve closes, and the coolant is directed to the engine radiator. If the coolant does not move to the upper radiator hose in time, the engine will heat up quickly.
  • Intake cylinder: This is also one of the quite important parts of the thermostatic valve. As the engine coolant temperature rises, the wax-filled cylinder will begin to melt and cause the main valve to open. The engine will be cooled by water sent straight to the radiator. The radiator exhaust valve will open if the coolant level is low and the wax is solid.
  • Spring: Responsible for closing the main valve when the cooling temperature has dropped below the specified level.
  • Seal: This prevents unwanted flow from going through the main radiator valve. In addition, when the seal is working correctly, the placement must be clean and tidy.

These are the basic parts that make up the thermostatic valve. Each piece is involved in the engine cooling process and helps the engine to operate smoothly and stably.

The principle of operation of the thermostatic valve is quite simple, specifically:

First, when starting the car, the engine is not warming up yet, so the thermostat is still closed, and the cooling process does not occur.

When the oil temperature in the engine is too high, the water valve begins to open to prepare for the cooling process.

The spring pushes the cylinder up when the coolant has a low temperature (below 87 degrees Celsius). The valve closes, and the coolant cannot move through the thermostatic valve.

When the temperature is 87 – 95 degrees Celsius, the spring and cylinder will go down, and the thermostat will open the water line from the engine to the radiator and cool the car.

The above principle is quite simple, and depending on each case, the valve will open or close differently. This is an automatic mechanism according to the function of each device.

How To Test Thermostat On Car

testing car thermostat
Testing Car Thermostat

How can i test my car thermostat without removing it? It doesn’t get as hard as you thought.

In fact, when there are signs of damage, testing car thermostat is something that users need to do immediately. Some notes to keep in mind:

  • First, check the temperature and coolant flow before removing the valve.
  • The user then starts the car, allows the engine to idle, opens the bonnet, and removes the radiator cap. In case there is coolant flowing out, it means that the thermostat valve is stuck.
  • If the coolant does not flow and the engine temperature gauge rises, the thermostat has a problem.
  • Also, users can use a thermometer to read the temperature in the engine block or cylinder head and then proceed to check the temperature of the upper radiator pipe. In case the temperature does not increase much, the valve is stuck. Conversely, if the radiator pipe remains at the same temperature, but the temperature gauge on the control panel rises suddenly, the valve is also faulty at this time.

There are many ways to check if the thermostatic valve has any problems.

However, to be sure, when users notice abnormal signs, bring them to the garage to be checked by a technician, pinpoint the problem, and have the appropriate treatment.

Signs Of A Faulty Car Thermostat?

Besides clear guidelines on how to test a bad thermostat, you have to recognize what signs of a thermostat failure. In particular, there are:

Poor Engine Performance

One of the obvious signs of a problem with the thermostat is that the engine’s performance is getting worse and worse.

Because their job is to help the engine operate stably and smoothly, when the valve has a problem, it also affects the machine and reduces performance.

Engine Overheating/Underheating 

This is one of the common symptoms of extremely dangerous thermostatic valve damage that users should pay special attention to since when the closed thermostat is stuck in the closed position, the coolant cannot move to the radiator fans.

If the engine block temperature gauge is overheated, it can also be caused by a damaged water pump or other reasons.

However, regardless of the reason, this is also a sign of serious damage that users need to bring the car to the garage to be handled promptly, avoiding dangerous situations.

Both are not good when the engine is too hot or too cold. In contrast to the above case, the engine is too cool because the thermostat is stuck in the open position.

Not only does it cause coolant to flow continuously into the radiator, but it also makes the engine too cool. This also affects the engine’s operation, making them less efficient and causing a lot of waste.

Fluctuating Engine Temperature 

One of the most common failures when the thermostat has a problem, is the fluctuation of the engine temperature.

Therefore, users should monitor the temperature gauge on the control panel regularly to detect errors early.

Once the needle falls, it may be because the car’s thermostat has a problem. It is necessary to check and deal with it soon carefully.

Coolant Leaks 

This sign is also quite common that thermostat issue valves often encounter.

When damaged, the liquid will be trapped in the closed position and seep out of the housing or valve through the pipes.

You can easily observe the water flowing down the bottom of the car. In the case of the coolant reservoir, it also greatly affects the engine’s operation, so you need to pay attention.

How To Replace A Bad Thermostat?

how to check car thermostat
The Ways To Replace A Bad Thermostat?

After how to test car thermostat, you want to replace it with a new one? There are 4 ways to follow:

Buy A New Thermostatic Valve

Valves are sold at auto parts stores at not-too-high prices.

You should provide complete information about the vehicle, such as make and year of manufacture, so the seller can get the right type of valve suitable for your car.

Remove The Old Thermostatic Valve

Before proceeding to remove it, you should drain the cooling water out. You can use a small container to collect the cooling water to prevent water from spilling onto the floor.

To drain the coolant, open the radiator cap and then open the drain valve at the bottom of the radiator.

After draining the coolant, find the location and use a wrench to remove the bolts on the thermostatic valve housing. Then take the valve out of position.

Note: Use a small knife to scrape off the grout on the body of the device.

Install A New Thermostatic Valve

Compare the old and new thermostatic valves to see if they are the same.

Use a clean cloth to clean the valve cover and valve mounting position.

Please insert the new thermostat into its housing, then place the new seal on the cap and apply glue to this part to create a tight seal when installed in the body.

Then fix each bolt into position and tighten evenly with moderate force to avoid damage to the thread of the joint.

Fill New Coolant

After the thermostat is successfully installed, you should tighten the drain valve at the bottom of the radiator and fill it with fresh coolant until it is full later.

Remember to screw on the radiator cap and then start the car to check for leaks.

So with a few simple steps, you can replace the new valve. This work is infrequent but necessary when your vehicle begins to show symptoms of damage related to thermostat replacements.

Following the instructional video:

FAQs

Is It Ok To Run A Car Without A Thermostat?

Yes, you can still run a car without a thermostat in it. However, your vehicle will easily overheat and get hotter.

The engines will have to work continuously so the coolant can flow through the cooling system, regulating the engine temperature.

Is it Easy To Fix A Bad Thermostat In A Car?

Yes, it is very easy to repair the thermostat and replace the faulty thermostat. In case you are not an expert, you can bring your car to the repair shop for inspection.

Conclusion

You only need to follow how to test thermostat on car above. We have shown you the details as well as the replacement of a bad one.

When your car’s thermostat is jammed shut, you can’t control the engine temperature, and other cooling system components won’t work.

As a consequence, regularly regulating the thermostat will make your car run safer and more effectively.

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