What causes high engine temperature in the new Focus?

[VanJoshua]

Possible causes include a faulty temperature sensor, excessive dirt on the radiator surface, or insufficient coolant. Below are relevant explanations: 1. Most vehicles use water-cooled engines, which rely on coolant circulation for heat dissipation. 2. The coolant follows two circulation paths within the engine: major circulation and minor circulation. 3. When the engine starts and remains relatively cool, the coolant undergoes minor circulation without passing through the radiator, facilitating rapid engine warm-up. 4. Upon reaching normal operating temperature, the coolant switches to major circulation through the radiator to maintain optimal engine temperature. Insufficient coolant leads to engine overheating. Similarly, excessive dirt accumulation on the radiator surface impairs cooling efficiency, resulting in abnormally high engine temperatures.