Why does the front of the car still make abnormal noises after the engine is turned off?

[EllieAnn]

Here are the reasons why the front of the car still makes abnormal noises after the engine is turned off: 1. Abnormal noise caused by uneven engine cooling: After the car has been driven for a period of time, the engine temperature is very high. After turning off the engine, the temperature of various components decreases, and thermal expansion and contraction cannot occur at a completely uniform rate. This inevitably leads to friction between the internal metal components of the engine due to cooling contraction, resulting in abnormal noises. 2. Turbo cooling sound: Under normal circumstances, the exhaust gas temperature reaches 600-700°C, accelerating the temperature generated by the rapid rotation and friction of the turbo. After turning off the engine, the thermal expansion and contraction will be very noticeable, thus producing abnormal noises. 3. Exhaust pipe cooling sound: Generally, the exhaust pipe can reach a temperature of over 200°C when the car is idling cold. If the car is under high load or there is a mixture of gases burning in the exhaust pipe, the temperature will be even higher.