Does Long-Term Idling with Air Conditioning On Damage a Truck?

[StReese]

Idling refers to parking the vehicle in place without pressing the accelerator pedal, allowing the engine to operate continuously at approximately 800 RPM for an extended period. Short-term idling has little impact on the vehicle, while prolonged idling, such as over an hour, is also not very harmful. However, idling can cause the following issues: 1. Idling may lead to oil burning: During idling, the throttle valve opening is small, and the intake manifold has a high vacuum level, which can draw oil vapor into the intake manifold. Some of this oil may deposit inside the intake manifold, forming carbon-like substances or coking. Prolonged low-speed or idling operation, especially in turbocharged models, may result in a pool of oil behind the throttle valve in the intake manifold, though this oil usually disappears after high-speed driving. 2. Idling promotes carbon buildup: During idling, the air-fuel mixture tends to be richer. Extended idling with a richer mixture can lead to carbon deposits in the engine. Similarly, low-speed driving with frequent stops and starts, such as 'accelerating and braking repeatedly,' where the engine alternates between fuel enrichment and reduced fuel injection, also contributes to carbon buildup in the engine.

[MacTalia]

As someone who's been driving trucks for over twenty years, I've seen too many messes caused by idling with the AC on. Last summer, a buddy of mine left his truck idling for three hours at a construction site, and the engine started burning oil afterward. The inspection revealed carbon buildup clogging the pipes, costing over a thousand bucks to fix. At idle, the low RPM leads to poor combustion, and the AC saps engine power, accelerating part wear. There's also the issue of fuel line blockages, especially with older trucks. My advice is to keep it under fifteen minutes or turn off the engine and use a fan instead, saving you the hassle and expense of a trip to the repair shop. Regular maintenance, like cleaning the throttle body, can extend engine life. Bottom line, it's not a good habit for the lazy—changing it will do your vehicle good.

[VanNatalie]

I believe the core of vehicle maintenance lies in preventing problems. Prolonged idling with the air conditioning on is definitely harmful to the car, as it causes incomplete engine combustion, leading to increased carbon deposits that affect performance. Truck engines are prone to overheating under heavy loads, and the additional strain from the air conditioning compressor makes matters worse. I've personally dealt with such cases where idling for an hour caused the engine temperature to spike rapidly, and the battery might also drain. It's advisable not to exceed 20 minutes, promptly turn off the engine, and check the coolant level. Develop a habit in daily driving—park in the shade, turn off the engine, and open the windows for ventilation. During regular maintenance, test the oil quality and check the air filter. These small preventive steps can save on major repair costs and keep the car running longer and more reliably.

[DeRicardo]

From both environmental and economic perspectives, this practice is too costly. Idling for one hour consumes fuel comparable to driving 50 kilometers, wasting money and polluting the environment. Diesel for trucks is extremely expensive, and doing this continuously for several days would skyrocket fuel costs. I've calculated that a single vehicle could spend hundreds more annually because of this. Increased engine wear leads to even scarier future repair bills. It's better to turn off the engine when parked and use an electric fan, or rest in the shade of a tree, saving money and reducing emissions. A simple change not only protects the vehicle but also benefits oneself.