Winter is coming, and that means cold starts and potential issues for your diesel vehicle. But with some preparation and maintenance, you can keep your diesel engine humming along all season long. In this complete guide, as a professional diesel engine parts supplier, I’ll share my top tips for keeping your diesel warm and happy when Old Man Winter comes knocking.
Why Keep Diesel Engine Warm in Winter
It is important to keep a diesel engine warm in winter for several reasons:
Prevent Fuel Gelling: Diesel fuel can gel or solidify at low temperatures, making it hard for the fuel to flow properly. Warming the engine and fuel system prevents gelling.
Easier Cold Starting: Diesel engines need high compression temperatures to ignite the fuel-air mixture. It’s hard to get high compression temperatures in cold weather, making cold starts difficult. A warm engine is easier to start in cold weather.
Maintain Proper Lubrication: Cold temperatures cause engine oil to thicken, reducing its ability to properly lubricate the engine’s moving parts during startup and operation. A warm engine allows the oil to flow more easily.
Prevent Condensation: Fuel tanks can get condensation, which can freeze and cause problems. Keep the tank full and the system warm to prevent condensation.
Extend Battery Life: Cold temperatures reduce a battery’s cranking power. A warm engine requires less cranking effort from the battery to start.
How to Keep Diesel Engine Warm in Winter
Use the Right Engine Oil
Let’s start with one of the easiest things you can do – swap out your engine oil. Most mechanics recommend switching to lighter synthetic oils in winter. Why? Because traditional heavier oils thicken up and don’t flow as well in cold weather.
That thick, sluggish oil makes it harder for your engine to turn over. It’s also tough on critical components like fuel injectors and pumps. No bueno!
Synthetic oils have improved cold weather performance and flow characteristics. I suggest using 5W-30 or even 0W-30 oil for max cold protection. Just be sure to check your owner’s manual – some modern diesel engines recommend surprisingly light oils.
Pro Tip: While you’re down there, replace the oil filter as well. A fresh filter ensures contaminants don’t clog up the system.
Give Your Battery a Checkup
Cranky cold weather is hard on batteries too. Low temps hinder chemical reactions, reducing available cranking power. Not exactly what you want on a frosty winter morning!
Pop your battery cables and give the posts and connectors a good scrubbing to eliminate corrosion. Check fluid levels if applicable. Consider having the battery load tested at your local auto parts shop too.
If your battery is more than 3 years old, it might be time for replacement. The newest AGM and gel cell batteries work great in winter. And don’t forget the battery warmer if you live where it gets super cold!
Love Your Glow Plugs
Time to show your glow plugs some love! Those unsung heroes are critical for cold starting diesels. Give the plugs a few seconds to heat up the combustion chamber before cranking.
Inspect plugs and wiring yearly – they can fail over time. Replacement only takes an hour or so. While you’re there, a new set of high temperature plugs never hurts. I run Bosch Duraterms in my rig all winter long.
Hot Tip: Consider adding an aftermarket glow plug controller. It precisely controls current flow for faster, more consistent heating. No more guessing if 10 seconds is long enough!
Flush Your Cooling System
Don’t neglect that cooling system either. Flush the radiator and swap coolant every fall. New extended life coolants have exceptional cold weather additives to prevent gelling and corrosion.
I’m a big fan of Final Charge GlobalMAX for my diesel. It’s organic acid-free, won’t damage gaskets, and tested to -84F!
While you’re at it, check your thermostat and radiator cap too. These inexpensive parts wear out over time, and the last thing you need is a stuck thermostat or coolant leak when Arctic air comes calling.
Give Fuel Filters Extra Love
We all know diesel fuel can gel up when it gets super chilly outside. The number one sign of fuel gelling? A clogged fuel filter shutting off the flow.
Before winter, inspect and change fuel filters if needed. Keep extras on hand just in case. Some mechanics recommend lightly spraying the new element with WD40 to help repel moisture.
You can also add an aftermarket fuel heater inline to warm things up. Or install a coolant-heated fuel filter that uses engine coolant to keep fuel from gelling. Just be sure NOT to leave it on all the time – it’s only intended for cold starting.
Use Winter Diesel Additives
Another tip is adding winter fuel additives and anti-gels to diesel. These magical fluids modify wax crystal formation so fuel keeps flowing. Brands like Howes Diesel Treat prevent filter clogging down to -40F!
I recommend adding additive with each fill up once temps drop below freezing. Dosing rates are based on ambient temperature and fuel tank volume. Most bottles have charts on the back.
A note of caution: don’t overdo it! Too much additive can damage fuel pumps and injectors. More is NOT better when dosing.
Install a Block Heater
As the name suggests, block heaters heat the engine block itself. Just plug it into 120v power to keep the engine warm overnight or during long downtime.
Block heaters slowly raise coolant temperature, circulating warmth throughout the block and cylinder head. It takes very little power but makes a huge difference in how your engine cranks over in the morning.
Many trucks come with block heaters already installed. Ask your mechanic to set one up if you don’t already have one!
Slow and Low is the Tempo
We talked about engine fluids and fuel already. Now it’s time to chat about THE most crucial fluid of all – you, the operator!
It’s essential not to push your engine hard until completely warmed up. I know it’s tempting to rush off to work with toast in one hand and coffee in the other. Resist the urge!
Cold engines struggle to generate heat. Pushing them too hard too fast increases wear dramatically.
Instead, heat up slowly and gently before working your rig. Let fluids circulate completely for 5 minutes of easy idling before pulling out. Remember – slow and low is the tempo when coaxing your diesel to life!
Wrap Up Your Radiator
If you don’t have a block heater, another tip is to insulate your radiator and charge air cooler. Protective wraps trap engine heat instead of letting precious warmth escape into the cold night air.
The nicest wraps have a waterproof reflective layer facing inwards. Some even have a plug-in battery warmer! I installed a Frost Shield wrap on my truck 4 years ago and it’s still going strong. Well worth the 1 hour DIY install.
In Conclusion
So there you have it – my top tips for keeping diesel engines happy in harsh winter weather. With a little planning and TLC, your truck will be ready to conquer whatever Old Man Winter dishes out!
Stay warm out there and let me know if you have any other cold weather diesel tips in the comments. I’m always looking to keep my rig happy when the mercury plunges!