A car thermostat in an engine is designed to maintain a minimum operating temperature. It keeps the antifreeze and coolant mixture within the engine and opens when a specified temperature is reached. The car thermostat is located between the engine and the radiator.
In this reading, we’ll explore what a car thermostat is, its function, diagram, types, how it works, and its signs of failure.
Let’s get started!
What is a Car Thermostat?
A car thermostat is a temperature-sensing device that measures the temperature of the engine coolant. The component is designed to open and close as needed to maintain an efficient temperature for internal combustion engines.
Thermostats remain closed if the coolant is not hot enough. But if the coolant reaches a specific temperature, it opens, allowing the flow of hot coolant into the radiator. So, the thermostat is just like a gate that allows or blocks the flow of coolant from the engine to the radiator.
Functions of Thermostat
A thermostat is a crucial component in a vehicle’s cooling system, responsible for regulating engine temperature. Here are its primary functions:
- The primary function of a thermostat is to control the working temperature of the engine.
- With the component, the engine is prevented from overheating and excess cooling.
- At a cold start, the thermostat blocks the coolant from flowing. This causes the engine to reach its working temperature faster.
- Also, it ensures coolant absorbs heat before entering the radiator.
- Finally, the thermostat controls the circulation of coolant in the overall engine
The components of a thermostat comprise wax, a rod, a cylinder, and a valve. The functions of these parts will be explained in the work.
Diagram Of A Car Thermostat
Related: What Is A Cooling System? Its Diagram and How It Works
Types Of Thermostat
There are two primary types of thermostats based on their design: those without a bypass valve and those with a bypass valve. Here’s a detailed comparison of these two types:
Thermostat Without Bypass Valve
Older cars typically have this type of thermostat; newer cars hardly ever have it. If the thermostat fails, the cooling water won’t stop flowing from the spare line that comes with this model, which is located on the radiator inlet. When the car engine is cold, water will become trapped in the radiator and water jacket. One benefit of this thermostat is its low cost. Still, there are downsides. A thermostat without a bypass valve lacks a safety line in case of a malfunction. Additionally, when the car engine is hot, there are no water lines to cool it down.
Thermostat With Bypass Valve
Modern cars use bypass valve thermostats. There is a bypass valve built into this type of thermostat, which is located at the radiator outlet. This type prevents the water coolant from circulating in the radiator; instead, it flows from the water jacket to the thermostat, which then enters the water pump and returns to the water jacket. Its bypass valve and safety line allow it to cool the engine quickly in case of damage. The downside is its high price due to its intricate design.
How A Car Thermostat Works
The thermostat is a small part that is located between the engine and the radiator of every liquid-cooled car engine. Designed to open and close at particular temperatures, it functions as a valve to regulate coolant flow. The thermostat stays closed when the engine is cold, preventing coolant from flowing to the radiator and enabling the engine to quickly reach its ideal temperature.
The thermostat opens to allow coolant to flow to the radiator and keep the engine from overheating after the engine temperature reaches the correct level, which is typically around 200 degrees Fahrenheit (95 degrees Celsius). The key to the thermostat’s function is the small cylinder positioned on the engine side of the device.
This cylinder is filled with a wax that begins to melt at 180 degrees F (82 C). A rod connected to the valve presses into this wax. The valve opens as the wax melts because it expands greatly and forces the rod out of the cylinder. In addition to expanding because of the heat, the wax expands a lot more because it is changing from a solid to a liquid.
Symptoms Of A Bad Car Thermostat
The thermostat in your vehicle plays a crucial role in regulating the engine’s temperature by controlling the flow of coolant. When it malfunctions, it can lead to various performance issues and potentially cause engine damage. Here are the key symptoms to look out for if you suspect your thermostat may be failing:
Overheating & Overcooling
The most typical sign of a malfunctioning thermostat is overheating. The thermostat in your car may become stuck in a closed position as a result of aging or corrosion. When this occurs, the engine will overheat and sustain serious damage since the thermostat will prevent the coolant from reaching the radiator.
Overcooling occurs when the engine’s temperature falls below what is necessary for normal operation. What happens is that the engine’s life cycle is significantly reduced because the coolant overflows the radiator due to the stuck-open thermostat.
Unusual Noises and Temperature Changes
Odd noises are another sign of a broken thermostat. The radiator may be making rumbling, boiling, or knocking noises. All these symptoms indicate a cooling system problem. Additionally, the thermostat controls the temperature of the air that enters your car through the vents. When it goes erratically from hot to cold or vice versa, it’s a telltale sign of faultiness.
Leaking Coolant
You can tell there’s a coolant leak if your vehicle has been overheating or if you see liquid trickling under it. Since the thermostat does not hold any coolant, it cannot be the culprit. It could be a gasket that’s stopping coolant from getting out of the thermostat housing.
Look for any deposits, drip marks, or droplets that could indicate a leak in the housing. Examine other parts if you see nothing out of the ordinary, as they might be the source of the problem.