What are the symptoms of a faulty fan coupling?
1 Answers
The symptoms of a faulty fan coupling are excessive or insufficient airflow. Excessive airflow prevents the engine temperature from rising in a timely manner, while insufficient airflow causes the engine temperature to become too high, affecting normal operation. The main function of the fan coupling is to engage or disengage the fan power based on changes in engine coolant temperature to cool the engine radiator appropriately. Causes of fan coupling failure include: 1. Damaged bimetal temperature sensor: When the bimetal temperature sensor is damaged, the silicone fluid fan coupling cannot engage or disengage in response to the air temperature behind the radiator, remaining constantly disengaged and causing the engine temperature to rise excessively. 2. Silicone fluid leakage: Silicone fluid is the primary transmission medium of the fan coupling. When leakage reaches a certain level, power transmission fails. 3. Broken silicone fluid fan drive pin: This causes the oil outlet valve to remain open under spring force, allowing silicone fluid from the oil reservoir to continuously enter the working chamber, keeping the fan coupling constantly engaged and causing the engine temperature to rise too slowly.