What Causes the Sound of Water Boiling After the Car is Turned Off?

[MatthewLynn]

Here are the specific reasons for the sound of water boiling after the car is turned off: 1. Uneven engine cooling: After driving for a period of time, the engine temperature is very high. Turning off the engine causes the gaps between various metal components inside the engine to cool and contract, resulting in friction and unusual noises. 2. Turbocharger cooling: Under normal circumstances, the exhaust gas temperature can reach 600-700°C, accelerating the heat generated by the rapid rotation and friction of the turbocharger. After turning off the engine, thermal expansion and contraction produce unusual noises. 3. Exhaust pipe cooling: When the car is under high load or there is a mixture of gases burning in the exhaust pipe, the exhaust pipe will also expand and contract due to heat, causing unusual noises, typically originating from the front end of the exhaust pipe and the flexible joint.