Why does a car's water temperature rise?

[StKathryn]

The reasons for an engine's water temperature being too high include: 1. Insufficient coolant: Prolonged water circulation during engine operation can gradually deplete the coolant in the engine's cooling system, leading to a shortage of water in the radiator. If the owner fails to promptly inspect and replenish the coolant, this can easily result in the engine's water temperature becoming too high. 2. Radiator leakage: A broken or improperly connected radiator hose can cause leakage, obstructing water circulation and, in severe cases, causing the engine to 'boil over,' which manifests as white smoke. 3. Cooling fan malfunction: Damage to the cooling fan or a short circuit in the wiring can prevent the fan from operating or cause it to rotate slowly, hindering the dissipation of the engine's heat and naturally raising the water temperature. 4. Thermostat failure: The thermostat controls the flow path of the coolant. If it becomes stuck or fails, the engine's large and small circulation cycles will inevitably be affected, preventing the effective dissipation of the engine's heat.