Is it normal to hear ticking sounds after the car is turned off?

[VanKingston]

This is a normal phenomenon caused by thermal expansion and contraction of some components in the engine compartment. Here is a detailed explanation of the ticking sounds after turning off the car: 1. When the car's engine is running, some components reach high temperatures. When the engine is turned off, these components cool down and undergo thermal contraction, producing audible sounds. 2. The exhaust manifold contains a catalytic converter, which reduces pollutants in the exhaust. This component operates at high temperatures during engine operation and produces noticeable sounds when cooling down after shutdown. This is completely normal and nothing to worry about. 3. For turbocharged engines, if you've just completed a long-distance drive, it's recommended not to turn off the engine immediately. Instead, let it idle for 2-3 minutes to help cool the turbocharger. After long drives, turbochargers can reach extremely high temperatures (some even glow red). The exhaust turbine is connected to the exhaust manifold, which also operates at very high temperatures.

[MacMichael]

I've been repairing cars for over twenty years, and those ticking sounds after the engine is turned off are all too common. It's the sound of metal parts like the exhaust pipe and engine contracting as they cool down. The longer and hotter the car has been running, the louder the noise. It's especially noticeable around the metal joints of the exhaust pipe as they cool. The catalytic converter also makes similar noises as it cools down. I always tell car owners that if the sound gradually fades as the temperature drops and disappears within a few minutes, there's absolutely no need to worry. But if it's still ticking after half an hour, or if there's fluid leakage or smoke, then it's time to get it checked immediately—it could be a crack in the exhaust manifold.

[HarleyFitz]

A new discovery two months after picking up the car: Every time I drive home from the elevated highway and turn off the engine, I can always hear a ticking sound like a clock coming from under the car. I asked my car-savvy childhood friend about it, and he said it's a normal operation of the exhaust pipe cooling down, just like how a red-hot iron block makes noise when water is poured on it. It's especially noticeable in summer, and I've recorded it lasting up to 8 minutes at its longest. However, if I hear a sound similar to a rolling screw, then I need to check for loose chassis components. Now, when I hear this sound in the garage, it actually makes me feel particularly at ease, as it means my new car's heat dissipation is working properly.