What are the hazards of leaving a car running for a whole day without turning it off?

[MacHarmony]

Here are the hazards of leaving a car running for a whole day without turning it off: 1. Carbon buildup: If the car remains idling for a long time, the engine will take longer to reach its normal operating temperature. The improper air-fuel mixture ratio in the engine leads to incomplete combustion, resulting in carbon buildup. Normally, cars will have some carbon buildup, which doesn't significantly affect the vehicle. However, excessive carbon buildup can cause the driver to feel a decrease in the car's power. 2. Increased fuel consumption: Idling causes carbon buildup, and excessive carbon buildup can further lead to increased fuel consumption. Besides the impact of carbon buildup, since the engine runs all night, it will consume fuel from the tank. If there isn't much fuel left in the tank, after a night of consumption, the car might even experience malfunctions. 3. Engine damage: Running the engine all night can cause significant damage. The engine contains many components that experience wear during normal driving. Continuous operation will undoubtedly worsen this wear and affect the oil pump, pistons, and even the connecting rods in the car.

[ReeseLynn]

I enjoy tinkering with cars, but leaving the engine running without shutting it off for a whole day can cause significant damage. Prolonged high-temperature operation of engine components can lead to lubricant failure, increasing friction and wear. Scratches may form on pistons and cylinders, and aging parts can result in costly repairs. It gets worse in summer—excessive radiator pressure can cause cooling system issues, and overheating might even destroy the engine. Carbon deposits build up rapidly, reducing fuel efficiency and compromising combustion chamber cleanliness. The fuel pump works nonstop, wasting gasoline; idling all day is equivalent to burning dozens of liters of fuel for nothing. Additionally, the battery drains heavily, making it prone to low charge during startup, and repeated instances like this drastically shorten its lifespan. Overall, it increases maintenance costs and requires frequent servicing, which is too much hassle. I recommend shutting off the engine when parked to protect your car.