Why Diesel Engine Starting in Cold Weather Doesn’t Have to Be a Problem

If you own a bus fleet or truck, you’ll know that cold weather and diesel engines sometimes don’t go well together. If you find it agonising to even think about starting a diesel car or truck in cold weather, don’t worry – we’ve put together this guide on top tips for diesel engine starting so you can keep your engine in good condition.

By following the tips below, you’ll soon discover that finding it impossible to start a diesel truck in cold weather is actually a myth!

1. Use fuel additives

Fuel additives can be added to your fuel in order to boost its performance. Diesel fuel often gels when the temperature plummets, which is where additives come in to help tackle any associated issues. For example, cetane boosters can enhance fuel ignition quality, improving combustion and resulting in quicker starts.

2. Change your oil

Cold temperatures can cause diesel engine oil to go thicker and flow slowly, placing pressure on your engine and affecting its overall health. Therefore, we recommend changing your oil regularly to keep your engine’s internal components fully lubricated.

Top tip: Once the cold weather hits, use lighter engine oil, which can flow more easily at lower temperatures.

If you’re having oil trouble, read our guide on what causes high oil consumption in diesel engines.

3. Try a winter blend fuel

Winter blend fuel is less viscous and less likely to gel in cold weather than summer blend fuel. This makes it perfect for starting diesel engines from a wide range of brands, such as Cummins and Mercedes, in cold weather.

4. Change your fuel filter

Before the cold weather has even fully set in, we recommend changing your fuel filter, reducing the likelihood that it freezes. A plus to doing this early is that you won’t have to tackle the chore in cold weather.

Top tip: You may also want to keep a spare fuel filter just in case your original one does freeze – after all, it’s usually much more straightforward to swap out a frozen one than it is to defrost one!

5. Follow best practices for storage

If you haven’t thought of this one already, make sure you store your diesel vehicles in a warm location – if you can! For example, heated garages, barns, or bus bases will do the job.

If you don’t like the idea of warming the room 24/7 or are worried about your vehicle overheating, put the heater on a timer to ensure the vehicles are warmed a couple of hours before you intend to use them. This could be the difference between successfully starting a diesel truck in cold weather or sitting frustrated in one which won’t work, which could make or break your company’s time efficiency.

6. Use glow plugs

If you’ve not already invested in glow plugs, now is the time to do so! Glow plugs heat your vehicle’s combustion chamber, enabling your diesel engine to start. Warming up your diesel vehicle’s combustion chamber in winter is integral because when the engine is cold, the diesel fuel fails to vaporise fully, resulting in incomplete combustion. Warming up this component can ensure your fuel mixes with air efficiently to burn completely.

Top tip: Remember to prepare ahead of time by inspecting your glow plugs before the temperatures start to drop – if they’re showing signs of wear and tear, be sure to invest in replacements that are up for the job so you’re fleet is always prepared.

7. Turn off non-essentials

A handy tip for maximising the chance of starting your diesel engine in cold weather is to turn off your non-essential components when possible. You have limited battery power – especially on a cold winter’s day – so avoiding using phone chargers, air conditioners, the radio, and more accessories might just help maintain your vehicle battery’s overall power.

Using less power can also keep your fleet clean to minimise emissions.

8. Warm up the batteries

Speaking of batteries, you’ll want to keep them warm. When the temperature drops, your battery can lose power, which can cause the engine to struggle. If you have the time, remove the batteries and bring them into a warmer space overnight so they can maintain a good temperature. If you’re willing to invest in a more convenient alternative, purchase a battery warmer to maintain the batteries’ temperature during nighttime.

9. Check your coolant

Coolant is made up of antifreeze properties, making it vital for your diesel engine in winter. It’s worth checking your coolant frequently, as cold temperatures can trigger the coolant to contract and possibly reduce its level. Ensuring it’s at the proper coolant level can prevent engine damage in winter.

Top tip: Don’t top your coolant off with normal water, as this could freeze in your engine. Always use a suitable water/glycol mix for maximum results!

10. Keep the tank full

By keeping your tank full, you can avoid the formation of condensation and reduce the risk of dreaded fuel gelling. Moreover, a full fuel tank can contribute to enhanced fuel pressure, which can often help you more effectively start your diesel engine in cold weather.

Top tip: Fill your tanks in the evening; a full tank won’t leave much room for water to condense in the night! You could also store portable fuel cans in a warm space overnight to avoid condensation.

11. Install another battery

As we’ve already mentioned, batteries can lose power during winter, so why not invest in a second battery just in case? Your glow plugs won’t work properly without the assistance of some proper battery power, so you’ll want to maximise your power where you can. Plus, as cold weather decreases a battery’s ability to crank an engine, a second battery can be a lifesaver. 

12. Invest in maintenance checks

Finally, you should never overlook regular maintenance check-ups. Here at Foxwood Diesel, our team offers repair and maintenance services to help ensure your diesel engine stays up and running. Regularly inspecting different components, from pistons to fuel filters, can help us uncover and resolve any common diesel engine problems. In turn, this can ensure your car, bus, truck, or other diesel vehicle can start in cold weather.

We can also offer high-quality new and reconditioned parts to maximise your vehicle’s performance.

You may cause damage to your diesel engine if you attempt to continuously start it in the cold without our recommended precautions. However, if you follow our best practices above, there’s no reason you can’t safely start your diesel engine in cold weather!

You may struggle to start your engine once the temperature drops below -12°C, as this is when your diesel fuel starts to gel. Employ our top 12 tips to help minimise gelling and ice problems!

Hopefully, you now have a better idea about starting a diesel truck in cold weather. Whether you own a bus fleet or agricultural equipment or simply want to become a pro at starting a diesel car or truck in cold weather, we have your back.

If you have any questions or are still experiencing engine trouble, don’t hesitate to contact us. Our team is very knowledgeable on new and reconditioned engine solutions and will be able to provide a service to help get your vehicle back on the road in no time.