What Causes the Dripping Sound Under the Chassis After Parking?
1 Answers
After parking, the dripping sound under the chassis is caused by the cooling sounds from the three-way catalytic converter, exhaust pipe, turbocharger, etc. Below are detailed explanations: Cooling Sound from the Three-Way Catalytic Converter: The normal operating temperature of the three-way catalytic converter is between 400-800°C. After turning off the engine, the three-way catalytic converter gradually stops working, and its temperature decreases. The metal components inside then undergo thermal expansion and contraction, resulting in abnormal noises. Cooling Sound from the Exhaust Pipe: During cold idle, the exhaust pipe can reach temperatures above 200°C. Under high vehicle load or when there is combustion of the air-fuel mixture in the exhaust pipe, the temperature can rise even higher. Consequently, the exhaust pipe also undergoes thermal expansion and contraction, producing abnormal noises. These sounds often originate from the front end of the exhaust pipe and the flexible joint area. Cooling Sound from the Turbocharger: Under normal conditions, the exhaust gas temperature can reach 600-700°C, and the rapid rotation and friction of the turbocharger generate additional heat. After turning off the engine, the thermal expansion and contraction are quite pronounced, leading to abnormal noises.
