Will leaving the car running for 8 hours without turning it off cause any damage?
2 Answers
This won't cause any significant damage to the car, but it will increase carbon deposits in the engine. When the car's engine is idling, the combustible air-fuel mixture cannot burn completely, so prolonged idling will lead to increased carbon buildup in the engine. Here are the reasons why the car might not start with one push of the button: 1. Excessive carbon deposits: This could be caused by too much carbon buildup in the idle speed control valve, intake tract, intake valves, or combustion chamber. 2. Too rich or too lean air-fuel mixture: Due to excessive carbon deposits or dirt in the intake tract, the cross-sectional area of the air passage changes, resulting in an overly rich or lean mixture, causing abnormal combustion or engine shaking after startup, or even failure to start. Alternatively, it could be due to issues with the fuel injectors, such as leaks or excessive carbon deposits, leading to a lean mixture during startup and difficulty starting. 3. Faulty carbon canister or carbon canister solenoid valve: Malfunctions in the carbon canister or its solenoid valve can also cause difficulty starting.
I've been driving for twenty years, and in the early years, I also experienced forgetting to turn off the engine. Once, I parked in the company parking lot in the morning without shutting off the engine, and when I got off work in the evening, I found the car was still running—a full eight hours without stopping. The most direct impact was a sudden surge in fuel consumption. Idling for an hour wastes about a liter of fuel, so I estimated I burned through ten liters unnecessarily, costing over a hundred yuan. Prolonged engine idling also increases component wear, such as more intense friction between piston rings and cylinder walls, faster degradation of lubricating oil, and potential buildup of more carbon deposits that affect performance. Although modern cars are designed to be sturdy and generally won’t break down immediately, frequent idling like this can shorten the vehicle’s lifespan. After that incident, I developed a habit of turning off the engine as soon as I exit the car and confirming the dashboard lights are off before locking the door. Additionally, safety is a concern, especially in garages or enclosed spaces, where excessive carbon monoxide from exhaust fumes can pose a poisoning risk.
