So, you know that traditional holiday song that plays during winter claiming it’s the most wonderful time of the year? Yeah, well, I say, ba-humbug. Winter is one of my least favorite times of the year. The warm sun dips below the horizon well before the workday is over. Ever-changing snow forecasts make transportation more complicated. And my personal favorite, the air hurts my face — why do I live in a place where the air hurts my face? Anyway, winter is brutal for many reasons, but it’s also just part of the arrangement when you live anywhere in our nation’s northern half. It’s not only trying for us; it can get pretty harsh for our vehicles, too. If you own a diesel truck, you’re a leg up on being prepared for the inclement months. However, you’re not entirely in the clear.
There are all sorts of things that need to be functioning correctly throughout the bitter season to take full advantage of your truck. Which means right about now, you need to be checking those parameters before it’s too late. We’ve got a list of twelve tips from our friends at Mishimoto that’s sure to help keep your diesel truck adequately outfitted in the upcoming harsh winter. We stopped by R/T Tuning in Montgomeryville, PA, while they worked on winterizing a 2007 Chevy Silverado Classic Duramax so that we could record some of the steps. Read along and save this list for any future winters, too!
Test Your Battery
This one seems like a no-brainer, but it’s not. When was the last time you checked your battery and tested its output? Likely never, until your truck clicks instead of turning over. That’s what makes this step so crucial.
But why does the cold weather impact the battery? Batteries use chemical reactions to produce essential electrons for power. Once the ambient temperatures drop, the speed of the reactions inside the battery slows down. The slower reactions result in less output. If your battery is on the edge of barely having enough current to crank over, it’s going to be an issue.
Think about this, too. As the weather gets colder, your engine’s oil thickens and causes more resistance while starting. Along with that, freezing temperatures can reduce your battery’s capacity by up to 20-percent. So, go to a local auto parts store and test it before the cold weather begins, and you’ll save yourself from the dreaded no-start. R/T Tuning had its own Battery Load Tester on-site, which made checking output a breeze.
Check/Replace Your Belts, Boots, and Hoses
Most of the belts, boots, or hoses in your truck’s engine bay are rubber. What does weathered rubber do in cold weather? It becomes brittle, and it breaks, leaving you stranded on the side of the road waiting for a service vehicle while you freeze — sounds terrible. Prevent this scenario by checking your belts for any cracking or torn strands around the edges. R/T Tuning elected to switch out the serpentine belt and tensioner for this vehicle, as prolonged use had worn the current setup, and it’s a reasonably straightforward job to replace both.
That takes care of the belt, but the rubber boots, lines, and hoses occupying the engine bay needed some attention, too. Check if any of these show any signs of leaking, cracking, or if they’re no longer flexible. These clues indicate that it’s either time for a replacement piece or a new fastener/clamp. Give these items a good squeeze and inspection. Each should be slightly spongy and return to its shape quickly. If you’re unsure about it, replace it.
In this instance, the truck was still utilizing the OE coolant hoses and intercooler tubes with somewhere around 125,000 miles of use. To remedy this, the Silverado received an update to one of Mishimoto’s Silicone Coolant Hose Kits and Hot Side Intercooler Pipe and Boot Kit.
The silicone coolant hose kit is a direct-fit for any 6.6-liter Duramax-equipped 2006–2010 Chevy or GMC. It is made of four different layers of heat-resistant fibers and silicone, reduces heat in the engine bay, and increases the system’s pressure tolerance — especially when compared to OE pieces.
As a precaution, a Mishimoto solution for the intercooler pipe replaced the OE unit. This replacement killed two birds with one stone by ridding the bay of a failure-prone factory piece and correcting the brittle rubber boots. This upgrade will ensure no boost leaks present themselves throughout the bitter cold months and improves airflow to the engine.
Test/Change Your Coolant
This step is more important than you may think. Coolant is always meant to be liquid. If it freezes, you can bank on some severe damage happening to your engine. There are preventative measures in place like press-fit plugs — or freeze plugs — that are made to rupture if internal fluid freezes. However, after a failure, the leaking coolant system that these produce is the best-case scenario. Harsher results include damage to the engine block or cylinder liners. The remedy for these, of course, is a new engine.
You can prevent any of those listed failures by ensuring your truck’s cooling system has the correct antifreeze and water mixture. If the coolant hasn’t been changed in a while, now is a good time to do so. The fluid can become heavily saturated with sediment and particulates, which reduce its thermal efficiency. Mishimoto even offers direct-fit coolant filtration kits if you want to get down with some preventative maintenance to help future you.
While R/T Tuning navigated the hose replacement and the coolant flush, they also opted to check/change the radiator itself. If the vehicle’s stock unit shows any signs of wear or leaks on the end tanks, or if the fins on the core are damaged, changing out the cooling system’s most influential component is not a bad idea. It is significantly easier to switch while the coolant system is empty and the hoses are detached. For this Silverado, Mishimoto’s full aluminum, two-row radiator was the upgrade of choice. The new unit will prevent any faults that may have arisen on the old OE radiator and dissipate heat better during the warmer seasons’ higher temperatures.
Proper cooling and protection of internal passages from freezing requires a 50/50 mix of water and antifreeze. Although coolant testers do exist, we found it easier in this instance to replace the coolant as the hose upgrade mentioned above required the draining of the system anyway. The replacement for the system’s antifreeze was Mishimoto’s Liquid Chill synthetic engine coolant. Available in both full strength and 50/50 premixed, this fluid is formulated to operate in varying extreme conditions and proven to get your vehicle up to temperature quickly.
Inspect/Boil Your Thermostat
The thermostat is such a small aspect of an engine, but another piece of the cooling system that should be functioning correctly before winter approaches. Keep in mind that this component is in direct contact with engine coolant, and it frequently experiences substantial temperature fluctuations. Unfortunately, your truck’s thermostat can fail in two different ways. It can fail open, which will continuously circulate antifreeze through your entire cooling system. While this might not harm any components, it sure will take a lot longer for your heat to get warm inside the cabin. The thermostat can also fail closed, which will prevent your engine’s coolant mixture from circulating into the radiator. It will create overheating issues at a minimum but will more likely cause engine damage or a blown head gasket if not treated.
If your thermostat has failed, you’ll know it, but if you want to inspect it for yourself, there are a few ways to do so. Once your vehicle is warm, you can use gloves to touch the upper and lower radiator hoses to ensure they are both warm. If one is cold, the thermostat might not be opening, but you will feel extra hot hoses if the thermostat is stuck closed.
To check your thermostat’s functionality, you can visually inspect it for faults — like if it’s stuck open or has damaged sealing materials — or you can boil it. Once you’ve performed an initial check, add your thermostat to a pot of boiling water, give it a quick stir and watch to ensure it opens. Similar to cooking clams and mussels, if it doesn’t open, it’s trash.
Age plays a role in the wear and tear on your thermostat. If you have a lot of mileage on your truck and have never replaced the thermostat, consider doing so before winter strikes.
Check Glow Plugs/Intake Grid Heaters
A glow plug’s function is to heat the combustion chamber for cold starts. It is a plug that threads directly into the cylinder head with its tip inside the combustion (or pre-combustion chamber). When it is energized, the plug itself can heat up to over 1,800ºF. This temperature spike helps your diesel engine’s combustion along in a cold-start situation.
If it’s summer, you probably won’t even know your glow plug failed. However, once those temperatures start to dip, your truck may have trouble starting or not start at all. Like any lightbulb, it’s damage to the heating element that usually causes a failure. This heating rod is exposed to high temperatures during combustion and can melt and degrade over time. Don’t cheap out, either. The tips of some low-quality plugs can also swell inside the head, leading to unwanted and costly repairs.
Testing your glow plugs can seem intimidating, especially since you will have six to eight plugs, but it’s worth it. Trust us.
One of the best ways to test glow plugs is by using a testing device, which provides a definitive answer of whether or not you will need to replace one or more plugs.
Change Your Oil
It’s fundamental to automotive ownership, yes, but it’s so crucial for correct winterization, too. As we mentioned in the battery section above, your oil thickens in the cold, creates more resistance to engine operation, and makes starting difficult. Cold oil has trouble circulating through passages and galleys to lubricate the engine components. To alleviate this issue, you need to increase the oil flow when cold to eliminate the possibility of dry-running engine wear.
Although all vehicles will differ, many recommend switching from a 15W-40 to 5W-40 during the winter months. Check your owner’s manual before making this switch, but switching to a thinner oil can reduce wear on your starter, battery, and injection system. This oil weight will provide greater flow during cold temperatures yet retain the same viscosity properties once warmed. If you live in the tundra and will never look at a wood chipper the same way again, 0W-40 might be recommended for your climate.
In our case, the crew at R/T Tuning preventatively installed a Mishimoto Oil Catch Can to deal with any oil blow-by issues — and a Mishimoto Transmission Cooler — so they switched out the fluids while it was still hot on their brain.
Wash The Undercarriage
Regular washing should already be part of your routine vehicle care regimen. However, many areas will spread rock salt or brine across popular roadways in the winter to prevent falling snow from freezing. While the salt might contain excellent properties to prevent freezing, it also expedites corrosion on any metal surfaces — your truck’s undercarriage included. Leave crusty salt on for prolonged periods, or continuously add to it without washing away old evidence, and you’ll be dealing with plentiful rust issues in no time. Try to wash away the salt regularly after snowstorms throughout winter, and you might combat those issues before they begin. A good underside coating probably isn’t a bad idea either.
Prevent Fuel Filter Gelling
Diesel fuel contains kinds of paraffin with a high freezing temperature that can cause a gelling symptom of your fuel, making it a solid material. Gelling can result in a clogged fuel filter, clogged lines, and likely an engine shut-down situation. Besides, diesel fuel systems are also susceptible to water and moisture buildup that, too, can freeze, clogging the lines and the filter. There are a few steps you can take to prevent any of this from happening:
• Dry Your System: Before winter, ensure that all water is removed from your fuel system. Several additives are available that utilize isopropanol to remove existing water. Numerous companies offer separator kits that are easy to install and work well, one of which is already installed on this very Duramax. These products are generally inexpensive, so treating your system is recommended.
• Change Your Fuel Filter: A dirty fuel filter will clog much quicker than a clean one. If you have not serviced this filter in some time, you should replace it before the winter season.
• Use a Winter Additive: You can treat your fuel tanks with additives that prevent both water and wax issues for additional protection. These additives are inexpensive and certainly worth the small investment.
Mishimoto Fuel Relief Diesel is the company’s own diesel fuel additive, though it’s not quite meant for improving conditions while driving during the winter. It is intended more for, say, a race truck that is being stored away during the colder period. Mishimoto’s additive helps with cleaning and stabilizing. It will prevent glow plug carbon buildup, reduce soot, and improve fuel economy and fuel delivery performance.
Ensure Proper Tire Tread Depth
We feel like we say this in so many of our articles, but it’s just because we’re such firm believers. There is only one item that separates your vehicle from the road, and that’s its tires. So they should be in good nick, then, right? Well, similar to your battery, how frequently do you inspect and test your tires? The answer is: not frequent enough.
Before the winter months, visually inspect each tire for rotting, cracks, bubbles, gashes, or damage. While you’re at it, check for any debris lodged in the tread that could cause damage later down the road. Last but not least, test and inspect the tread depth to ensure it’s well above the safety regulation lines. If the tread is bald, too close to judge, or past the limit, it would be wise to replace the tires before risking it in a handful of inclement storms.
Tires will be more prone to aging if a vehicle sits for an extended period. Typical tire compound life lasts from 6–10 years, depending upon storage conditions. Chemical reactions within the tire compound will degrade the rubber, resulting in reduced grip and an increased chance of failure.
For those facing extreme winters or planning to tow anything, an upgrade to snow tires will significantly differentiate grip and vehicle control. If you expect only a small snowstorm or two, you can likely press on with all-season tires, assuming you take it slow and drive respectably.
Check Your Windshield
Possibly the most effortless check on the whole list, your windshield is an item that impacts your truck’s ability to conquer the winter. Before winter hits, you’ll want to make sure your view isn’t obstructed with cracks that compromise the integrity of your windshield. It gets more challenging to check for tiny cracks and chips that could lead to that big crack. These small nicks are tiny and hard to see, but they only need a quick temperature change to spread. We’re sure you can imagine a cold winter day where you blast your defrosters to get warm. This moment is precisely when that crack will spread and ruin your day.
While you’re looking at your windshield, check your wiper blades to see that they’re in good condition. Rough looking wipers don’t clean snow, slush, or salt-laden water off your glass very well, and the replacement’s cost will range from $12-$30, so it’s an inexpensive switch.
Block Heater/Grille Cover
These two upgrades can make life so much better in the winter.
A block heater’s function is to keep the engine block and coolant warm during overnight parking. Just plug your block heater in a few hours before you start your truck. Then, when you are ready to drive, your truck’s engine is already warmed up. This heating makes starting more manageable and reduces the fuel consumption associated with cold starts. Block heaters are relatively inexpensive and typically pay for themselves in the form of comfort and convenience. If you are using an extension cord to reach your truck, make sure that you use one rated for your heater’s required wattage. Also, check your heater’s wiring to be sure it won’t cause a fire when left unattended.
A grille cover is another great way to rapidly warm your truck to operating temperature and keep those temperatures from over-cooling during idle conditions. Suppose your diesel truck struggles to stay warm. In that case, a grille cover is an inexpensive way to block airflow and improve interior heat capability.
First Aid Emergency Kit
While this list will help limit the failures you could experience during winter, it will not eliminate all possibilities, so we recommend outfitting your truck with some emergency supplies. This kit is especially important if you are traveling through extreme terrain or remote areas. Many people toss a bag of items in their backseat for year-round use; however, your winter kit should include items you will need in a cold-weather emergency. Below is a list of items you should consider stocking for emergencies. You can get pre-made kits that contain a majority of these necessities, or you can piece it together with what you own currently and make additions when needed.
- Small shovel
- Windshield scraper and brush
- Flashlight with extra batteries
- Several water bottles
- Snack food (energy bars, raisins, nuts, candy bars)
- Waterproof matches and small candles
- Hats, socks, and gloves
- First-aid kit
- Small knife
- Any medications you usually take (small portion)
- Blankets or sleeping bag
- Tow chain or rope
- Small bag of cat litter: for wheel traction in case you become stuck
- Jumper cables or a portable jump starter
- Emergency flares
That about does it for our suggestions to properly winterizing your diesel truck. We listed all twelve tips again below without any descriptions, so it’s easily transferrable and referenced on your phone. As always, if you have anything you think we need to add, drop us a line using our contact form, and we’ll gladly hear you out. Thanks for reading.
Photography by Brandon Cody
12 Tips To Help Successfully Winterize Your Diesel Truck
- Test Your Battery
- Check/Replace Your Belts, Boots, and Hoses
- Test/Change Your Coolant
- Inspect/Boil Your Thermostat
- Check Glow Plugs/Intake Grid Heaters
- Change Your Oil
- Wash The Undercarriage
- Prevent Fuel Filter Gelling
- Ensure Proper Tire Tread Depth
- Check Your Windshield
- Block Heater/Grille Cover
- First Aid Emergency Kit