What are the hazards of prolonged warm-up?
2 Answers
Prolonged warm-up can exacerbate carbon buildup. The correct warm-up method is: after starting the vehicle, let it idle for 2 to 3 minutes until the engine coolant reaches normal operating temperature, then you can drive. Not warming up the car can cause engine wear, as the engine oil settles at the bottom when the engine is cold, leaving the internal components in a state of dry friction. The purposes of warming up are: 1. After prolonged parking, the engine oil flows back into the oil pan, leaving the upper part of the engine without proper lubrication—warming up helps lubricate these parts; 2. When the engine hasn't reached operating temperature, the fuel system cannot effectively vaporize gasoline due to low temperatures—warming up improves efficiency; 3. It helps distribute transmission fluid to lubricate the upper part of the transmission.
Prolonged idling to warm up the engine is not a good habit. Having worked in auto repair shops for over a decade, I've seen too many vehicles develop issues due to excessive idling. While engines require lubrication during cold starts, prolonged stationary warm-up reduces oil fluidity, increasing friction between piston rings and cylinder walls—leading to premature wear. Incomplete fuel combustion also causes carbon buildup, clogging fuel injectors or spark plugs. Worse yet, it wastes gasoline, burning money needlessly while harming the environment. Modern engines aren't that delicate; gently driving for half a minute after startup allows natural temperature rise without pointless waiting. Persistent idling only increases maintenance costs, drastically shortens engine lifespan, and leads to expensive repairs.
