What are the symptoms of a faulty belt tensioner pulley?
2 Answers
The symptoms of a faulty belt tensioner pulley are as follows: 1. Difficulty starting. If the belt has not broken but is skipping teeth, it generally causes difficulty starting. After the engine barely starts, there may be symptoms such as poor acceleration and increased fuel consumption. If the belt breaks, it can lead to valve damage or even complete failure of the valve system. If the timing belt fails, the vehicle should be stopped immediately and towed to a repair shop for inspection. 2. Abnormal noise and slipping. The belts at the front of the engine include the water pump and fan belt, alternator belt, air conditioning compressor belt, and power steering pump belt, among others. Belt slipping noise is a sharp, piercing "squealing" sound, similar to a whistle, often occurring when the engine is first started, during acceleration, or when the air conditioning is turned on. Belt slipping may be due to insufficient belt tension or excessive wear or aging of the belt, which reduces the friction coefficient. To determine if the engine noise is caused by belt slipping, you can sprinkle a small amount of water on each belt after turning off the engine and then restart it. If the noise decreases or disappears, it indicates that the noise was caused by belt slipping. When there is belt slipping noise in the engine, the tension of each belt should be checked first. The standard tension for belts varies between different engines, but generally, when a force of 50-100N is applied vertically with the thumb to the middle of the belt between two pulleys, the deflection of the belt should be about 10mm. If the tension is too low, it should be adjusted. If the noise persists after adjustment, it indicates that the belt has aged and should be replaced.
As a driver who often operates older vehicles, I've experienced a faulty belt tensioner pulley. The symptoms include constant squeaking or chirping noises from the engine compartment, particularly louder during acceleration, resembling metal friction sounds. The belt may appear loose and can be easily moved with a light press, causing it to slip, deform, or even come off. This affects the alternator, making the battery light flicker and causing insufficient charging; the air conditioning compressor also stops working, resulting in no cool air inside the car, severely impacting driving comfort. I recommend stopping to check as soon as you hear unusual noises, otherwise, the belt will wear out faster, potentially damaging the water pump or steering system, leading to costly and time-consuming repairs.
