Ways to Start a Diesel in the Cold

January 16, 2024

How to Start a Diesel in the Cold

Since diesel engines need high temperatures to ignite their fuel, starting a diesel in the cold, known as a cold start, can be challenging. Thankfully, you can take some actions to make starting your vehicle easier. 

Understanding how to start a diesel in the cold can help you reduce stress when you drive and give you peace of mind that your vehicle is in good shape.

Why Is It Hard to Start a Diesel in the Cold?

Starting a diesel in cold weather can be challenging because this fuel requires high temperatures to ignite. An engine uses compression to create the heat necessary to ignite diesel fuel, and low outdoor temperatures can hinder this process. Additionally, diesel fuel can start to gel when temperatures drop below 30 degrees Fahrenheit or lower. If fuel begins to thicken, it can clog the fuel filter or form wax crystals.

Cold temperatures also affect vehicle batteries. When temperatures drop, the chemical reaction within a battery slows down, reducing its efficiency.

9 Tips for Starting Your Diesel in the Winter

Knowing how to start a diesel in the cold can help you avoid challenging hassles and interruptions. Having peace of mind that your vehicle will operate properly can help the winter months pass smoothly, so consider these tips to start your engine more easily this winter:

1. Warm Your Vehicle Before Starting

Warming your vehicle before starting it can help your diesel engine start easier. Most diesels have a block heater to pre-heat the engine and oil, helping to reduce the viscosity of the oil and improve the overall starting performance in cold weather. This process ensures easier cranking and faster warm-up, promoting efficient combustion and minimizing wear on engine components. The colder the outdoor temperature is, the longer your engine will need to warm up before it can start. Running the block heater for two to three hours before starting your engine may suffice on a moderately cold day, but you will need to run it overnight on frigid days.

2. Ensure Your Fuel tank Is Full

Fuel is less likely to ice in a full fuel tank because a full tank leaves little room for condensation to form and freeze. Avoid waiting until your tank is almost empty to refill it. Instead, try to fill it more often throughout the winter.

3. Change Your Oil

Changing your diesel vehicle’s oil regularly is crucial to ensure its weight or viscosity is correct below zero even when colder temperatures settle in. Oil adds resistance to a vehicle’s moving parts when it thickens. A diesel vehicle is easier to start and creates less wear when it is the correct weight or viscosity.  Hot Shot’s Secret offers engine oils and oil additives such as Stiction Eliminator to keep your engine running smoothly in warm or cold.

4. Replace Your Filter

Your fuel may have gelled if you struggle to start your engine on a cold day. Replacing your fuel filter can make it easier to start your engine and protect your engine for greater longevity. Purchasing a new fuel filter is more cost-effective than getting a new engine, so checking your filter periodically and replacing it if you notice any clogging is vital.

5. Change Your Vehicle’s Batteries

Replacing your batteries can help your vehicle start easier if you have trouble starting it. During the pre-start process, many diesel engines use glow-plugs or a grid heater to warm the engine and aid in starting. This strains the batteries during this heavy load process. Older batteries are likely to struggle to crank the engine after the pre-heat process.

Batteries lose a significant amount of their capacity when temperatures lower, so it’s essential to change them before winter arrives if you notice them under-performing in the summer. You should typically change a vehicle’s batteries at least every  years, but you may need to change them more frequently.

6. Avoid Using Non-Essential Accessories

Non-essential accessories such as phone chargers, radios and heaters use battery power, reducing the amount of energy provided to your engine. Limiting the devices you use allows your engine to access the battery power it needs to operate effectively.

7. Warm Your Engine With a Block Heater

A block heater warms your engine’s internal combustion chamber. It has a cord you can connect to your engine block and contains an element that heats your engine’s coolant to keep the oil warm. Connecting a block heater to your engine overnight can make it significantly easier to start in the morning.

8. Use Winter Diesel Fuel

Diesel #2 and Diesel #1 are two different fuel grades you can choose for your vehicle. Since Diesel #1 contains less wax, it more resistance to gelling than #2. Many people use #2, but blending #2 with #1 can help prevent or reduce fuel gelling. 

9. Prepare Your Vehicle With Fuel Additives

Winter diesel fuel additives can help you prepare or winterize your vehicle before the temperatures begin to fall. Using fuel additives can achieve:

  • Fuel gelling prevention
  • Clean injectors
  • A cetane boost for faster diesel cold starts

Additives help lower an engine’s cold filter plugging point (CFPP). The CFPP is a standard test that determines a diesel engine’s fuel flow rate through filtration devices in cold temperatures. Hot Shot’s Secret offers high-quality diesel fuel additives such as EDT+ Winter Defense to keep your engine running smoothly in the cold.

How to Prepare Your Diesel Vehicle for Winter

Since fuel additives help winterize your vehicle, choosing the right product as you prepare your vehicle for the cold season is essential. If you use winter fuel, make sure you add the correct amount of additives to avoid over-winterizing your vehicle. 

It’s also important to add fuel additives when temperatures exceed the CFPP mentioned above. Using them at warmer temperatures above the CFPP allows them to mix with your vehicle’s fuel properly. The best time to add fuel additives is directly after filling your tank with diesel #1D fuel. The fuel from the pump is typically warm enough for the additives to mix correctly.

Prepare Your Diesel Engine for Winter With Quality Additives From Hot Shot’s Secret

Hot Shot’s Secret offers EDT+ Winter Defense and Diesel Winter Anti Gel to help you lower your diesel fuel’s cold filter plugging point. With this fuel additive, you can prevent clogged fuel lines and filters when winter temperatures arrive. In addition to lowering your fuel’s CFPP, you can use our winter additives to improve your fuel’s stability, detergency, winter operability, lubricity and cetane number to improve cold starts.

We also offer Diesel Winter Rescue, an emergency product you can keep on hand in case your diesel freezes. This product includes a lubricity additive and a military-grade de-icer to re-liquefy gelled fuel and de-ice frozen filters. You can use Diesel Winter Rescue to restore your diesel engine’s power and fuel flow if the cold temperatures cause complications.

Choose Hot Shot’s Secret Products

Hot Shot’s Secret is dedicated to helping customers fix diesel engine complications. You can use our products to resolve issues without making expensive repairs, and our highly concentrated formulas are more reliable and impactful than the diluted solutions retail stores typically offer. When you use Hot Shot’s Secret products, you can expect them to resolve your engine’s problems and improve its performance. 

Purchasing Hot Shot’s Secret Diesel Winter Anti Gel and Diesel Winter Rescue can help you prepare your vehicle for the winter months. Browse our fuel additives or locate a store near you to start getting ready for colder temperatures.