What to Do When the Water Temperature Gauge Shows Too Low Temperature?
2 Answers
The solutions for the water temperature gauge showing too low temperature are: 1. Check the coolant level to see if it has significantly decreased, and add an appropriate amount if necessary; 2. Check if the coolant has deteriorated, and if so, clean the water passages and replace the antifreeze; 3. Check the engine oil level, and add or replace the oil if it is insufficient; 4. Check if the fan blades are deformed, and replace the fan or adjust the belt if needed; 5. Check for any blockages in the water radiator and whether the radiator air ducts are obstructed, and clean them thoroughly; 6. Check if the water temperature sensor and its circuit are short-circuited or open-circuited; 7. Remove and inspect the thermostat, place it in hot water to observe its opening condition, and replace the thermostat if it fails to open properly.
Having driven for over a decade, when encountering a low reading on the coolant temperature gauge, the first thing to check should be the thermostat. This component acts like a water valve—if it's stuck in the open position, the coolant keeps circulating in a large loop, preventing the temperature from rising. I experienced this with my old Passat before; replacing the thermostat fixed it immediately. This issue is especially common in winter because the engine cools down too quickly during cold starts. Additionally, if the heater isn't blowing warm air, it's almost certainly a thermostat problem. It's also worth checking the coolant level—too little can cause slow warm-up. This needs prompt repair, as prolonged low temperatures are particularly harmful to the engine, fuel consumption will spike, and oil emulsification becomes an even bigger headache.
