Owners of classic cars may not think or realize that the engine thermostat is an important part of the engine operating properly. Far too often people feel that when the car engine overheats the simple solution is to remove the thermostat and “problem solved”. That really is not the case as the engine is not really operating at its peak performance without the thermostat. We have already discussed the other parts of the cooling system as well as the importance of using the correct coolant/anti-freeze in your classic car engine with the last critical component of this system being the thermostat.
Let us look at what this part does, how to diagnose failures, and how to fix it.
What Is a Thermostat?
A thermostat valve can be described as a device or component which is sensitive enough to sense the temperature of a system such as an automotive system so that the temperature is kept at a desirable point. It is a device in an automotive that controls cooling or heating automatically in such a way as to maintain the temperature nearly constant. This coolant control serves as a regulator that is automatically regulating temperature by starting or stopping the supply of heat in the engine. It is also widely used in many other systems not just automotive.
To maintain a needed temperature, control is applied by switching the devices on or off which thereby regulates the flow of a heat transfer fluid as required for the maintainability of the correct temperature. It is important to properly operate the device to achieve the best result of controlling heating and cooling of the automotive.
What Does the Valve Do?
Also known as the thermostat valve or simply the thermostat, this valve is responsible for moderating the temperature of a vehicle’s engine. While many of us are aware of the potential perils of an engine overheating, an engine also will not work properly when it is too cold. Therefore, it is the job of the thermostat to regulate the temperature between these extremes, creating a happy medium that promotes optimum driving by controlling the flow of coolant that can circulate the engine. The thermostat valve allows coolant to circulate and keeps the engine cool.
As it functions as a valve, the thermostat has 2 positions: open and closed. When the valve is in the open position, coolant can flow through it, which lowers the engine’s temperature. When the valve closes, it blocks the entry of fresh coolant to the engine, allowing it to warm up. This part works alongside your vehicle’s radiator. When the coolant has become too warm, it passes it back to the radiator, which works to return it to a suitable temperature.
Cold Engine – When the thermostat determines an engine is too cold, it closes itself. This prevents coolant from leaving the engine and being cycled to the radiator for cooling. This allows the coolant to warm up with the engines heat, warming the engine overall.
Hot Engine – When the thermostat determines the engine is becoming too hot, it opens. This allows fresh, cold coolant to enter the system, which starts to cool it down to a safer temperature. The coolant which had become warm is cycled out to the radiator for cooling.
In short, without your vehicle’s thermostat, your engine is at risk of running too hot and overheating or running too cold and shutting down. The thermostat keeps the engine at its optimum temperature, meaning the parts of your engine system can work to the best of their ability and will last longer, all while giving you the best drive possible in the process.
How Does Car’s Engine Thermostat Work?
Between the engine and the radiator of a liquid-cooled car engine is a small device called a thermostat. The thermostat’s primary function is to keep the car’s engine to a minimum operating temperature for optimal performance. The coolant mixture is usually conserved within the engine by the thermostat when a car’s engine is started cold. When the temperature of the coolant achieves the set startup point of the thermostat, it starts automatically. The coolant then flows through the radiator and keeps the running engine at the thermostat rated temperature. It is worth noting that when the engine is cold, no coolant flows through it. The operating temperature of an engine is usually about 200 degrees F or 93 degrees C. The thermostat opens once the engine reaches this operating temperature. By performing this function, the thermostat reduces the engine wear and save the driving force from many other hazards.
Importance of a Properly Operating Thermostat
It is highly recommended and important to have a properly operating thermostat valve to achieve the best cooling and heating effect of the engine. If a thermostat is functioning properly, it will be an advantage in the following areas:
- Engine overheating will be avoided
- Engine wear is minimized
- The car will warm up to a normal engine operating temperature within the required time
- Maintain gas mileage
- The car engine will be running optimally thereby giving you a smooth driving experience
- Catalytic converter damage and fouled spark plug problems are reduced
- Improved fuel economy
What Is a Stuck Valve?
The most common issue a thermostat valve can have, which will cause it to cease functioning, is it becomes stuck in the open or closed position. This will cause your engine to either become too hot or too cold, severely affecting the performance of your car.
If you are concerned that you might have a stuck valve, you can check and test the valve yourself following the steps below:
- Preparation – Disconnect the negative battery cable and drain some of the coolant from the system. This will prevent any spillages when testing.
- Removal – Remove the upper radiator hose. This will then allow you to remove the thermostat housing and finally the thermostat itself. When removing the thermostat, write down the temperature that is stamped on it.
- Testing – Fill a pot with cold water and insert a thermometer. Add the thermostat and place the pot on your stove. Keep your eye on the thermometer. Once the temperature reaches the number that you recorded, it should start to open. If this happens, then it means your thermostat is in working order. If this does not happen, or the thermostat only starts to open at higher heats, it is faulty and needs replacing.
Upkeep And Potential Issues with Your Car Thermostat
- Thermostats are rated for a specific temperature depending on the engine – not a one size fits all proposition. They are subject to normal wear.
- Proper operation depends on a special wax that expands as it heats up to open a spring-loaded valve. A worn thermostat could stick in the open position causing the engine to run too cool. This is inefficient and could hurt performance and fuel economy.
- If a thermostat sticks in the closed position, the car engine can quickly overheat, possibly causing damage.
- There isn’t a specific maintenance routine for the thermostat but maintaining your cooling system by changing your coolant/antifreeze according to schedule will make sure the coolant has enough corrosion inhibitors to protect the thermostat and other vital system components.
- Many cooling systemexperts recommend that you replace your car thermostat when you do a full coolant flush or exchange. Plus, thermostats usually wear out faster than your hoses, so if you need to replace worn hoses, replace the thermostat at the same time.
- Of course, if your temperature warning light comes on, have your cooling system inspected right away. This could be a thermostat problem. The thermostat could also be the culprit if you are not getting hot air when you turn on your heater.
- Bottom line, your car thermostat is a relatively inexpensive part that stands guard between you and catastrophic engine damage.
Finally
A properly operating thermostat help to keep the engine at its optimum operating efficiency. When an engine is in its cold state, it uses more gas because gas does not vaporize efficiently as it does within a warm engine. The coolant must spend some time in the radiator unit to allow the fan and air to cool it off before being returned to the engine block for the cooling system. A lot of people believe that removing the thermostat from the car will make their car run cooler. It is simply the opposite. Without the thermostat, the coolant will pass through the radiator rapidly which does not allow enough time to cool down in the radiator, thereby inflicting possible engine damage. It is highly recommended that the thermostat valve is properly maintained.
It’s good to know that the temperature valve is key to moderating the car’s temperature. I would like to take my car to a mechanic this week because my car’s temperature gauge has been really weird this week. I think it might be an issue with the engine, but I’ll have to ask a professional.