Reasons for Slow Engine Coolant Temperature Rise

[SawyerFitz]

The slow rise in car coolant temperature is generally caused by a damaged thermostat that fails to close, or a malfunctioning cooling fan that remains constantly running. Solutions for slow engine coolant temperature rise are as follows: 1. Check if there are issues with the cooling system, such as: whether the radiator shutter is blocked, if the fan blades are deformed, or if the coolant temperature sensor and its circuit are short-circuited. 2. The thermostat can be removed and inspected by placing it in water at different temperatures to observe its opening behavior. If it fails to open and close properly, the thermostat should be replaced. Additional Information: The car's temperature should not be too low or too high; it needs to be controlled within a certain range. The normal temperature is 90°C, which is the middle position on the temperature gauge. After starting the vehicle, the coolant temperature should rise quickly, and the pointer should reach the middle position. Once thermal equilibrium is achieved, the coolant temperature will no longer rise. It is best to start driving when the temperature reaches the middle position.