How to Start a Diesel Truck in Cold Weather: Top Tips

Cold weather can be a problem for businesses with diesel truck fleets. As temperatures fall and snow covers the roads, you may face trucks that won’t start. Whether you manage a fleet of diesel trucks or are an owner-operator, knowing how to start a diesel truck in cold conditions is vital. You also must take proactive steps to prepare your diesel truck for winter driving. Doing so will help avoid disruptions and keep business operations running smoothly all winter.

Why a Diesel Truck Won’t Start in Cold Weather

Diesel engines are generally harder to start in cold weather than gasoline engines. This is because they need high compression-generated temperatures to ignite the diesel fuel. Below -15°C, starting a diesel engine is five times harder than at 25°C. Besides, diesel fuel is harder to ignite in the cold because it can gel, starting at about -9°C. This can lead to various problems, including forming wax crystals and clogging the fuel filter.

Understanding Why Diesel Truck Engines Struggle in the Cold

So, understanding how to start diesel truck in cold weather is based on the physical properties of fuel, which becomes thick in low temperatures. It occurs because there is paraffin wax and water in the formula. Both components change their structure when the temperature goes down, which results in fuel gelling and clogged fuel injectors. The engine does not receive the fuel, and the diesel truck won’t start in cold weather.

The engine oil thickens too and creates resistance to a diesel cold start. Moreover, when freezing, condensed water in the fuel system clogs filters and prevents fuel from flowing into the engine. Also, the constructional reasons, explained above, like low compression, glow plug malfunction, and grid heater issues, make things more difficult. In the cold, even a strong accumulator can lose up to 60% of its starting power and, as a result, its efficiency decreases. Our logbook service allows truck owners to track vehicle performance and ensure that the cranking system is serviceable under any temperature conditions.

How to Start a Diesel Truck in Cold Weather

So, how to start diesel truck in cold weather? The key to diesel cold start and providing the necessary cold cranking amps to start your diesel engine is heating the engine so that the fuel can ignite. You can do several things to warm your diesel engine and avoid frustration efficiently. The next sections will discuss the three main engine heating methods to start your diesel truck in cold weather.

Heating Methods When You Have Trouble Starting a Diesel Truck

To help diesel engines start in cold weather, these three engine heating methods can make a difference:

Glow Plugs

Glow plugs generate heat to help power the diesel engine, drawing energy from the truck’s battery. They are used to start diesel engines by increasing the air temperature in the combustion chamber. The air in the chamber must be compressed to a small fraction of its original volume to reach a temperature of 400 degrees, which is necessary for igniting the engine.

The time glow plugs take to warm up varies from a few seconds to a minute, depending on the external air temperature. When the glow plugs reach the right temperature, the glow plug warning light will turn off, signaling you can try to start the engine. If the engine doesn’t start within 30 seconds, turn the key until the light comes back on, allowing the glow plugs to warm up again for another minute. Avoid flooding your engine in this process.

Block Heater

If the glow plug methods fail, a block heater can help start a diesel in cold weather by warming the engine block, which houses all internal engine components. To use a block heater, you need an outlet plug. Connect the block heater to the plug extending out of the vehicle. Use an extension cord to connect the cable to an outlet.

Keep your truck plugged in for at least two hours before starting the diesel to allow the block heater to warm the coolant inside the engine block. Once adequate time has passed, attempt to start the diesel engine. This process still involves waiting for the glow plugs to warm. Proceed to turn the key and start the engine.

Intake Heater

Another method of diesel cold start involves using the intake heater located in the intake manifold. This heater warms the air entering the engine cylinders. To use this method, first turn the key in the ignition to start warming the glow plugs. Once they are warm, start the engine. The intake heater will then use battery power to warm the air in the pipe, ensuring the air entering the combustion chamber is already warm. This allows the chamber to heat up faster, helping the diesel start faster in cold weather.

11 Tips for Diesel Truck Starting in Cold Weather

If you want to know how to start a diesel in cold weather without a block heater, you should try the following recommendations:

1. Prefer winter-grade diesel fuel with supplements that prevent gelling.
2. Or add supplements to a fuel tank when the temperature goes down.
3. Ensure that the tank is always full (at least 50% full) to avoid fuel line freezing.
4. Use synthetic oil intended in particular for cold weather.
5. Ensure that there are no failing glow plugs and replace those if any.
6. Let a vehicle’s engine run in neutral for about 5 minutes to warm up the systems.
7. Regularly test your accumulator and replace it if it is degraded.
8. Avoid skipping replacement intervals for fuel filters.
9. Park a vehicle in warm places.
10. Use a blanket to warm up an accumulator.
11. Disable all accessories (the radio, fan).

You can reduce cold weather struggles by various methods, but taking preventative measures will definitely help your diesel engine operate flawlessly without interference. Also, if you use our dispatch services, you can contact our dispatchers and say, “My diesel truck won’t start in the cold.” Our technicians consult you by phone about what should be done.

Conclusion

Cold weather causes many problems for diesel engines, from gelling fuels to drained batteries. However, you can overcome winter operational issues with diligent preparation and maintenance. Performing preventative maintenance can help your diesel truck start a lot better during winter driving! Still, if you face challenges, now you know how to start a diesel in cold weather without a block heater or using the heating methods.