Function, Installation, and Testing of a Thermostat in an Engine Cooling System
Keeping the engine cooling system operating correctly is crucial for servicing large machinery like tractors and excavators. The thermostat, one of the main parts of the cooling system, is essential. What function does the thermostat serve in the engine cooling system, then? How should the thermostat be installed in the engine? And how can I check if the engine thermostat is operating correctly? MyMROmarts will address your queries one by one in this post.
What Is the Function of a Thermostat in an Engine Cooling System?
By controlling the flow of coolant in the following two states, the thermostat keeps the engine running within the ideal temperature range at all times.
1. Stay closed during cold start
When the engine is just started, the thermostat will close, preventing the coolant from flowing to the radiator. This allows the engine to quickly warm up to the optimal operating temperature. This can improve fuel efficiency and reduce wear.
2. Open at high temperature
Once the engine reaches a predetermined temperature (usually 190-220 degrees Fahrenheit), the thermostat will actively open and allow coolant to flow to the radiator. This can dissipate excess heat and prevent the engine from overheating.
Which Way Does a Thermostat Go in an Engine?
Correct installation of the thermostat is key to ensuring its normal function.
1. Clear installation direction
Thermostats are usually marked with "top" (engine side) and "bottom" (radiator side). The top should face the engine and the bottom should face the radiator.
2. Spring end facing the coolant flow direction
The spring end of the engine thermostat needs to face the coolant inflow direction. This is to sense the engine temperature and respond in time.
3. Check the sealing gasket
Be careful to check whether the sealing gasket around the thermostat is damaged. This can avoid coolant leakage.
4. Tighten the bolts with a torque wrench
Use the appropriate torque as required by the equipment manual. Be careful to avoid over-tightening and damage to parts.
Incorrect installation of the engine thermostat will cause the coolant to not circulate properly. At the least, it will cause the engine to overheat, and at the worst, it will damage the engine.
How to Test Engine Thermostat?
There are three ways to determine whether the thermostat is working properly:
1. Coolant temperature test
Start the engine and let it reach normal operating temperature.
Use a thermometer to measure the coolant temperature at the radiator inlet. If the temperature reaches the thermostat's rated value (usually 82℃-90℃), but the thermostat does not open, there may be a problem with the engine thermostat.
2. Manual touch test
After the engine has been running for a while, touch the radiator's water inlet pipe with your hand (be careful of high temperatures).
If the water inlet pipe remains cold after the engine warms up, the thermostat is not open.
3. Hot water test
Use a thermometer to check the water's temperature after submerging the thermostat in a pot of hot water.
The thermostat valve should progressively open as the water temperature gets closer to the thermostat's calibrated temperature, such as 195 degrees Fahrenheit. It indicates a malfunctioning thermostat if it opens partially or not at all.
Although the thermostat is small, it is a key component in the engine cooling system. Understanding its role, the correct installation method, and testing techniques can help you maintain your excavator, tractor, or loader efficiently.
If your equipment needs a thermostat replacement, choose high-quality replacement parts from the MyMROmarts store. Check your cooling system regularly and replace the thermostat promptly to keep your equipment running at its best.