When To Replace The Thermostat of Your Truck

Do you know when you need to replace the thermostat in your vehicle? If not, then this guide will take you through when you should do it. Several activities take place in the engine, which generates a lot of heat. Too much heat from the engine is dangerous as it can melt down the plastic hoses and seals. Apart from that, the engine itself can break down. The engine has a cooling system that ensures it works at its optimal temperature. 

What is a Thermostat?

The cooling system is a vital part of your truck, and it comprises various components such as the radiator, coolant, and thermostat. What is a thermostat? For the cooling system to function effectively, it has to have what triggers it. A thermostat is a temperature-sensing device within your engine. It opens and closes automatically to regulate the temperature of the engine. 

The thermostat closes when the coolant has just been released into the engine. When the coolant in the engine reaches a specific temperature, it will open to allow the hot coolant to flow into the radiator. The role played by the thermostat exposes it to wear. It is necessary to know the appropriate time to replace the thermostat. 

Signs that You Need To Replace The Thermostat

Your truck will exhibit some signs when your thermostat is worn out and faulty. Knowing such signs will aid you in determining when to replace them.

High Temperature

High truck temperature is the first sign that you need a new thermostat. The temperature of your truck can increase when the coolant level has gone down. But if you have just refilled your coolant and this persists. Consider checking your thermostat.

To determine that high temperatures result from a faulty thermostat, look for a spike in temperature. For example, your thermostat may be defective if your truck’s and engine’s temperature is cool but spikes very high within a short time.

Cold Engine

Mostly, people associate a hot engine with a faulty faulty thermostat, but when your engine is too cold, it is another sign that your thermostat is defective. A cold engine is dangerous and interferes with the operation of your truck.

The prominent role of a thermostat is to let the coolant move to the radiator. When the thermostat remains open, the coolant will keep flowing regardless of your engine’s temperature. It will make your engine cold and bring mechanical problems to your truck.

Problems with the Temperature Gauge

The easiest way of accessing your thermostat is by checking the temperature gauge. You must have needle nose pliers to remove your thermostat.

After removing your thermostat, consider cleaning it and placing it in hot water. Before doing this, consider checking the temperature of the water. Check the temperature gauge when the thermostat is in hot water. If it does not spike, then your thermostat is faulty.


Shared in this guide are some of the things to watch out for to determine whether you need to replace the thermostat. Between your engine and the coolant, there is a thermostat whose primary responsibility is to ensure that the coolant flows in and from the engine when necessary. When it becomes faulty, your engine will either overheat or become cold. Knowing the signs of a faulty thermostat will enable you to determine when you need to replace the thermostat.

How To Troubleshoot Faulty Thermostat In Your Car

As you perform regular maintenance for your car, a point will come, and you will need to know what a thermostat is and its role in your vehicle. But the most important thing is knowing that a thermostat can stick close or open. Your engine requires coolant to operate smoothly, and the thermostat regulates the coolant flowing to the engine. When you ignite your car in the morning, the thermostat remains closed as it waits for the coolant to attain a specific temperature. Generally, the thermostat’s opening and closing regulate your engine’s temperature. Here is how to troubleshoot faulty thermostat in your car.

How To Troubleshoot Faulty Thermostat In Your Car

Occasionally, your thermostat might fail to open or close at the right time. It is not difficult to troubleshoot thermostat issues. Here is how to approach the issue.

Check Your Temperature Gauge

If you see your temperature gauge hitting the red position within fifteen minutes of driving, your thermostat might be faulty. Generally, your thermostat should not take a lot of time to open. As soon as you start your car, it takes less time for the adequate temperature to build up to facilitate the thermostat’s opening. But if you see the temperature gauge hitting the red part in the first 15 minutes, it is evidence that your thermostat is not opening. 

Check the Condition of The Radiator Hoses

If you realize your engine is heating up, the first thing to check is the radiator hoses. Confirm if any of them is leaking and if there is no leakage, assess the temperature of the hoses. If some are warm and others are cold, then conclude that your thermostat is not opening.

How To Verify The Status & Troubleshoot Faulty Thermostat

If your car exhibits any of the above signs, the thermostat housing might leak due to pressure at the thermostat. To verify the status of your thermostat, you need needle nose pliers and water. Perform the following steps.

Step 1. You have to remove the thermostat from its housing.

Step 2. Take your thermostat to the kitchen as you boil some water on the stove. As the water is heating, ensure its temperature does not exceed the temperature calibrated on the thermostat. To determine this, you must have a thermometer.

Step 3. After the water has attained the required temperature,  hold your thermostat with the needlenose pliers and deep it in hot water. The thermostat should be able to open when the water reaches a specific temperature. 

It would help if you were very keen when doing this because sometimes the thermostat might be attempting to open and close. If such happens, your thermostat is faulty, and you should replace it as soon as possible. 


As your engine is operating, several factors make it heat up. The combustion in the cylinders produces heat as well as friction. Engine coolant performs the role of containing the temperature of your engine. The thermostat performs the function of regulating the flow of coolant in the engine. If it is faulty, there are high chances of your engine not receiving coolant, leading to engine overheating. 

Your thermostat can be faulty, and this guide has elaborated on determining whether your thermostat is defective and how to troubleshoot it.