Will leaving the car running for several hours have any impact?
2 Answers
Leaving the car running for several hours will have an impact, primarily on the engine. If the vehicle remains in a parked but running state for an extended period, the engine will operate at low RPM for a prolonged time, increasing carbon buildup on the piston valves, leading to unstable idling or other adverse effects. In severe cases, it may even affect the engine's lifespan. When the engine operates at low RPM, the leakage between the valves and piston rings increases, while the intake vortex weakens, resulting in poor fuel atomization and incomplete combustion. The combustion gases inside the cylinder will have prolonged contact with the cylinder walls, increasing heat loss and making it difficult to disperse oil mist, significantly raising the engine's fuel consumption.
I'm the most qualified to speak on this matter. Just last week, I left my car running at a gas station for two hours and came back to find the fuel gauge had dropped significantly. Actually, prolonged engine idling is particularly harmful to vehicles, with the most obvious issue being oil consumption. At low RPMs, the piston rings don't seal well, allowing engine oil to seep into the combustion chamber and form carbon deposits. The mechanic showed me the piston tops, which were completely black. Another major problem is the emission system - the catalytic converter doesn't reach optimal temperature and becomes more prone to clogging, which is why the exhaust smells bad. But the most concerning aspect is the safety risk. What if someone gets in and drives away? Not only could valuables be stolen, but in an enclosed garage, there's also the risk of carbon monoxide poisoning. Now I've developed the habit of always checking the dashboard when exiting the car - if the hazard lights are blinking, I know the engine is still running.
