5 Negative Impacts of Excessively Idling Diesel Engines

Excessive idling can be more harmful to diesel engines than many operators realize. While it may seem like a harmless way to keep a construction machine ready for use, extended periods of idling can lead to long-term damage and inefficiencies that impact both the performance of your heavy equipment and your bottom line.

Here are 5 ways too much idling can be bad for a diesel engine:

1. Carbon Buildup: Prolonged idling can lead to incomplete combustion, which causes carbon to build up in the engine — especially in the exhaust system, turbocharger and cylinders. This can reduce engine performance and efficiency over time.
2. Fuel Contamination: When a diesel engine idles for long periods of time, it doesn’t reach its optimal operating temperature. This can cause unburned fuel to dilute the engine oil, leading to increased wear and tear on engine components.
3. Increased Engine Wear: Diesel engines are designed to operate under load, and idling can create conditions of low cylinder pressure and reduced lubrication which can lead to increased wear and tear on your engine. Over time, these service costs can really add up.
4. Increased Fuel Consumption: Unnecessary idling wastes fuel without doing any productive work, which can hurt overall fuel economy and increase your operating costs.
5. Emissions and Environmental Impact: Idling increases harmful emissions such as nitrogen oxides (NOx) and particulate matter, which contribute to air pollution.

It’s important to note too that unnecessary idling will rack up hours on your machine while it’s just sitting there. It’s more of a business consideration than a maintenance one, but when you go to trade in your machine, those extra hours could come back to bite you on the resale value.

The good news is there are some simple things heavy equipment operators and fleet managers can do to reduce idle times and their negative impacts:

• Warm up under load: Try to avoid extended idling during warm-up. Instead, allow the equipment to warm up by gradually increasing the load during the first few minutes of operation. This helps the engine reach its optimal operating temperature more efficiently.
• Cool down after heavy use: Before shutting off the engine, especially after heavy use, allow the equipment to idle for 3-5 minutes to cool down the turbocharger. This prevents overheating and prolongs the life of the turbo.
• Set an idle time limit and use an automatic engine shutoff: Many machines will idle for as much as 40 to 60% of their operating time. And while some idling is necessary, excessive idling can become a costly habit. To lower idle times, use an automatic idling system where engine speed is reduced to idle when the controls are inactive for a pre-set amount of time. You should also look for an engine auto shut down feature that can shut down the engine if it’s stationary, not in gear, and has been idling for more than a pre-set amount of time.

• Consider using telematics programs: Many construction equipment fleets use telematics systems that track and report on idle times. You can regularly review this data to adjust your machine operating cycles to increase productivity while limiting excessive idling. Plus, it can also help you identify if any operators need additional training.
• Avoid idling for temperature control: Instead of running the engine solely to control cab temperature, equip machines with auxiliary power units (APUs) or use battery-powered climate control systems. This can drastically reduce fuel consumption during breaks or while waiting.
• Keep filters clean: Regular maintenance, including changing air and fuel filters, ensures that idling periods cause less damage, as the engine will perform more efficiently.

• Be sure your operators understand the impacts of idling: Ensure all operators are trained on the risks of excessive idling including its effects on engine performance, fuel efficiency and emissions. Reinforce the importance of shutting down engines when their equipment is not in use.
• Reduce warm-up idling in cold weather: In cold weather, use block heaters to pre-warm the engine coolant, reducing the need for extended idling. This allows for a quicker and more efficient warm-up.
• In colder climates, use a low-temperature diesel: In cold environments, use winter-grade diesel or fuel additives that prevent gelling, reducing the need for long warm-up idling.

Use these tips to not only extend the life of your equipment but also improve fuel efficiency, lower operating costs and reduce your environmental footprint. And if you’re an operator, here are some additional ways you can improve your company’s operating costs.