What is the inspection method for the thermostat?
3 Answers
The inspection methods for the thermostat are as follows: 1. Inspection when the engine is just started. Open the radiator filler cap. If the coolant in the radiator is calm, it indicates that the thermostat is working normally. This is because when the water temperature is below 70°C, the thermostat's expansion cylinder is in a contracted state, and the main valve is closed. When the water temperature exceeds 80°C, the expansion cylinder expands, and the main valve gradually opens, initiating the circulation in the radiator. If the temperature gauge indicates below 70°C, and there is water flow at the radiator inlet pipe with slightly warm water temperature, it indicates that the main valve of the thermostat is not tightly closed, causing premature major circulation of the coolant. 2. Inspection after the water temperature rises. In the early stage of engine operation, the water temperature rises quickly. When the water temperature reaches 80°C, the rate of temperature increase slows down, indicating that the thermostat is working normally. Conversely, if the water temperature continues to rise rapidly, and when the internal pressure reaches a certain level, boiling water suddenly overflows, it indicates that the main valve has been stuck and suddenly opened. If the water temperature at the filler port is low, and there is no water flow or very little flow at the radiator's upper water chamber inlet pipe, it means that the main valve of the thermostat cannot open.
When it comes to checking the thermostat, I've personally experienced the headache of my car's coolant temperature never reaching the proper level. The inspection process is actually quite straightforward. I usually start by running the engine and observing the temperature gauge for about 10 minutes. If the needle consistently stays in the cold zone or rises very slowly, there's a high probability the thermostat is stuck open, causing coolant to circulate too quickly. Additionally, I'll feel the radiator hoses near the engine to check for temperature differences - normally the upper hose should be hot while the lower one stays cool. If both hoses are cold or both are hot, that indicates a problem. For a more thorough check, I remove the thermostat and submerge it in hot water (around 85°C) to see if the valve opens automatically. This method reveals many hidden faults and helps prevent engine damage or excessive fuel consumption from overheating or overcooling. The key is performing these checks regularly, especially before long trips - it's both cost-effective and ensures safety.
As an enthusiast who enjoys DIY car repairs, I frequently inspect various components of my vehicle, and the thermostat is quite crucial. The method is as follows: First, start the engine when the car is cold and let it idle for 5 minutes, then keep an eye on the temperature gauge. If the needle rises too quickly or too slowly, it definitely indicates a problem with the thermostat. Second, turn off the engine and feel the upper and lower radiator hoses. A significant temperature difference is normal, but if it's minimal, you should be cautious. Third, when removing the thermostat, use a wrench and basic tools, then immerse it in hot water and measure with a thermometer. A good thermostat will open the valve at 80-90 degrees Celsius; if it doesn't move, it's faulty. The entire process requires patience to avoid burns. This approach can save a lot on repair costs and extend the vehicle's lifespan.
