It’s okay when it’s freezing – but it’s not okay when your diesel won’t start up, you’re not only losing comfort. Time and appointment slots are being lost, and so is your money. The operational issue with cold-start failures is that it results in missed pickups, late delivery risk, and unnecessary downtimes.

Most winter no-start problems are preventable with appropriate preparation — fuel, batteries, heaters, maintenance — but when they do occur, a clear troubleshooting protocol is imperative to overcome the situation without potentially harming the engine.

Why a Diesel Truck Won’t Start in Cold Weather

The key difference between diesel and gasoline engines makes it more challenging to start the diesel on cold days. Diego Engines differ from gas-burning engines because they are made to be “lit by the compression of air in the cylinder. The air needs to be squeezed down to 16% of its original volume, bringing the fuel temperature up to 400 degrees, for it to burn when injected into the chamber. As you can imagine, this process can be somewhat hindered by cooler weather, which is why a diesel truck won’t necessarily start up in cold weather. Spark plugs, of course, are used to start the gas in gasoline engines. What is the lowest temperature that is too cold for a diesel engine?

In cold weather, particularly with №2 diesel and not using additives, diesel fuel can turn to gel. Then, depending on blend, additives, and exposure, many operators begin to have problems somewhere in the mid-teens °F or so, which is why the fuel in winter prep. is important.

How to Start a Diesel Truck in Cold Weather

The key in terms of how to start a diesel truck in cold weather and provide cold cranking amps to start your diesel engine is being able to heat up the engine in order for the fuel to ignite. When it comes to making sure you can get your diesel engine to temp quickly and save yourself some time and aggravation, here are a few things to try: We will start with the three main engine heating methods, but also include a list of things to keep in mind – reduce downtime and restart risk, or have discovered during our years in business helping owner-operators of trucking businesses.

Heating Methods When You Have Trouble Starting a Diesel Truck

Glow plugs, block heater, and intake heater are the three major ways to get it hot when it is too cold for a diesel engine, and you are facing problems starting your diesel truck. It’s wise to have an idea of exactly what equipment you’ve got, and if you do have to embark on a lengthy road trip with the temperature plunging, have alternatives in place.

Glow Plugs

Glow plugs resemble the spark plugs of a gas-powered engine and are powered by the truck’s battery. Turn the key to run, but not start. Glow plugs can take a few seconds to a full minute to get to temperature, at which point, the “Glow Plug Wait to Start” indicator light will turn off. Repeat the following steps if the ignition fails to turn over in 30 seconds or less: re-ignition, turn the ignition key to the start position, and then to run for a second time. Afterward, turn the warm-up plugs on and repeat the process.

Block Heater

This is a more complex and time-consuming process — and is typically done in conjunction with glow plugs. It will reduce the temperature of the truck’s engine block and coolant. The block heater plug is similar to an extension cord and extends toward the bottom of the engine, typically in the vicinity of the battery, headlight, or grill. The block heater is plugged into an outlet plug, and the plug is placed in the truck’s grill. It is possible to require an extension cable. Keep in mind that some trucks have the ability to run the plug through the front of the truck. Once things are plugged in, leave them alone for two to three hours prior to starting the truck — more (six hours to overnight) when the temps are below 10.

Intake Heater

Quickest and non-smoking intake heater method. Residing in the intake manifold, the intake heater heats the air that is sucked into the cylinders. It is energized from the truck battery, similar to the glow plugs. Rotate the ignition key and wait for the glow plugs to heat up; start the engine. This intake heater will perform its function, heating up the air entering the combustion chamber and thus increasing the rate at which the engine temperature rises.

Winter delays also shorten your legal driving window, and when you’re busy enough to begin with, it would be nice to know what driving times a truck driver has legally between HOS violations before planning cold-weather legs.

Tips to Avoid Trouble Starting Diesel Engine in Cold Weather

However, just like any other vehicle, it’s important to plan trips and take care of the truck to prevent excessive problems with cold starts. Become familiar with your trucks and what is in them, and make your plans for long, cold vehicle trips in advance. The more work that you get done ahead of your trip, the quicker you can get some prep underway and hit the road.

• Be aware of the contents of the tank. Was the diesel truck full of #1, #2, or a combination of diesel fuel when it was parked? #1 is less viscous and has a higher concentration of cetane, making it more volatile and thus easier to ignite. It may also be laced with additives. #2 Diesel fuel has a higher viscosity and is less volatile, which makes it more fuel efficient and suited to warm weather conditions. Using #1 fuel during the winter may feel like more of a hit to the pocketbook, but it may allow your truck to warm up and get on the road faster.
• Consider using a winter fuel additive. The “Cold Filter Plugging Point” is reduced so that the fuel doesn’t gel or freeze in the engine or tank. The important thing is that the additives must be injected at slightly elevated temperatures (e.g., immediately after filling with #1 diesel) to ensure proper mixing of #1 diesel with additives. Be sure to use an additive that rates 10 degrees or more below the lowest temperature you may encounter. Most importantly, never put additives in fuel that was already “winterised”, since additives may not be compatible and negate previous benefits.
• Regularly change the oil. High-quality, fresh oil maintains alignment and lubrication of parts, and influences the ignition time as well. Older, thicker oil makes an engine two or three times harder to start at 0 degrees and below. If you change the oil in your diesel truck, you’re going to enjoy better performance not only in the winter season, but year-round.
• Warm up the oil. The heated dipstick that fits into an oil outlet port can be used to heat the oil in the crankcase. If you’re careful and desperate, as some drivers have done, you can plug in a hair-dryer (with a long extension cord), insert the nozzle into the air inlet duct, and slowly warm up.
• Have a battery just for glow plugs. A lot of electricity goes into powering the Glow plugs, and they use your truck’s battery to operate. Also, a battery’s ability to hold its charge decreases in colder weather — it may be capable of holding 100% when it is 75 degrees, but only 50% at 0. Running the glow plugs off another battery will help you avoid draining the other battery as well as charging the glow plugs sufficiently. If you have enough room under the hood, you could consider getting a greater-capacity battery instead.
• Or purchase a battery warmer. The two most popular battery warmers, either of which can be plugged into a 110-volt power source, are called the “hot plate” and the “electric blanket.” This “hot plate” is similar to a pan stand that you would place your battery on. The “electric blanket” is not only useful when the temperatures really plummet, but it can also use more electricity than the “hot plate”. This is a warmer, as the name suggests, and it’s wrapped around the battery.
• The fuel tank must be kept full. A full fuel tank helps to prevent condensation from occurring and stops your fuel from freezing. Also, change your fuel filters regularly.
• Keep your diesel truck warm when you want to start it in cold weather. Putting your diesel truck to bed in a heated garage may head off a great deal of headaches if you need to make preparations to get ready for a cold winter road trip. The same can be said about any equipment that you will use to help heat your diesel engine.
• Allow sufficient time for your diesel engine to warm up. There are situations in which it will be better to take a few minutes to ensure the heater cools your engine, rather than rush the process and cause problems later.
• Avoid using “engine-starting fluids”. The containers may have instructions on them, but it is very difficult to accurately measure safe proportions, and the ether in “engine-starting fluids” burns at much lower temperatures. The last thing you want is to start an explosion or fire, which could result in serious damage to your diesel truck – and you, of course. If you’re adamant on using an “engine-starting fluid,” have the starting-fluid injection kit installed (and stay away from starting-fluid sprays).

Cold start problems can cause roadside incidents and breakdowns, as well as heighten the inspection profile – particularly during a FMCSA safety audit process.

When you can’t find the answer, seek assistance. Don’t hesitate to have a certified diesel mechanic give you professional advice and service to discover the source of the cold temperature issues. A diesel professional can help ensure that your company’s efforts to increase your truck don’t backfire and, in the long run, do harm to your primary asset—the operator! Take note that, in the long run, you do not want to start using the try-and-fail strategy, but prefer paying the right amount for proper diagnosis and recommendations. As appropriate, always use the expertise and knowledge of professionals. Driving is more valuable than your time is worth!

Keep Moving in Winter Without Losing Revenue

Cold-start failures not only waste a morning – they waste a schedule! None of the operators that continue to earn a profit in the winter do that by incurring downtime, buffer times, or wasting driving time.

When you’re working under your own auspices, and you want little or no “fire drills” this winter, Arrow dispatch services helps with:

• Weather risk + HOS aware load planning
• Together with the protection of the margin, there is also rate negotiation in place, which protects the margin in case delays occur.
• Clean compliant operation support
• Billing + document flow – no admin theft of drive time
• Call in the arrow dispatch services for more predictable weekly operation, even in cold weather.