What are the techniques for troubleshooting abnormal noises inside the car?
1 Answers
Techniques for troubleshooting abnormal noises inside the car involve identifying and addressing the causes one by one. The reasons for abnormal noises after the car is turned off are as follows: 1. Cooling sound of the three-way catalytic converter: The normal operating temperature of the three-way catalytic converter is 400-800°C. After the car is turned off, its operation gradually stops, and the temperature decreases, causing the internal metal components to expand and contract with heat, resulting in abnormal noises. 2. Cooling sound of the exhaust pipe: Generally, during cold idling, the exhaust pipe can reach a temperature of over 200°C. When the car is under high load or there is a mixture of gases burning in the exhaust pipe, the temperature can be even higher. Therefore, the exhaust pipe also expands and contracts with heat, producing abnormal noises, often originating from the front end of the exhaust pipe and the flexible connection. 3. Cooling sound of the turbocharger: Under normal conditions, the temperature of the exhaust gases can reach 600-700°C, accelerating the friction-generated heat from the turbocharger's rapid rotation. After the car is turned off, the heat expansion and contraction are also quite noticeable, leading to abnormal noises.
