Is it harmful to leave the car running for three hours without turning it off?

[VonBriella]

Leaving the car running for three hours without turning it off can lead to engine carbon buildup and fuel consumption. Here are the relevant details: 1. Engine carbon buildup: Prolonged idling of the vehicle will not cause fatal damage, but it can result in engine carbon buildup. Carbon buildup occurs when the vehicle operates at low speeds, and when it accumulates to a certain extent, the vehicle's power will weaken, and fuel consumption will increase. If your car's power weakens after prolonged idling, you can take it to a professional auto repair shop to clean the carbon buildup. After cleaning, the vehicle's power will improve significantly. 2. Fuel consumption: The vehicle also consumes fuel while idling. Therefore, after three hours of idling, you should check whether the car still has enough fuel. If the fuel level is low, it should be refilled as soon as possible.