How Are Snowmobiles Cooled?


You likely start off feeling pretty chilly at the beginning of your snowmobile rides, only to become warm and insulated the longer you’re at it. Internally, your sled does the same. Components such as the engine must stay cool, but how?

Snowmobile coolant flows within your sled’s system to keep the engine at the appropriate temperature when riding. These sleds are known as liquid-cooled snowmobiles. Some sleds are fan-cooled, which means fans redirect cool air to the engine to keep it from overheating.

In this article, we’ll discuss more about the differences between liquid cooling and fan cooling for your snowmobile. We’ll also talk about maintaining your sled’s cooling system and what to do if your snowmobile overheats. You’re not going to want to miss it! 

Liquid-Cooled vs. Fan-Cooled Snowmobiles: Which Is Better?

Between liquid cooling and fan cooling sleds, you’re far more likely to come across a liquid-cooled snowmobile. Both cooling options have their perks though, so we figured we’d start off with an explanation and then comparison.

What Is Liquid Cooling?

Like many everyday vehicles, the source of liquid cooling that snowmobiles utilize is coolant. You add this chemical to your engine’s reservoir, sometimes its expansion tank. Coolant, as the name suggests, can regulate or lessen the temperature of your engine. This happens when the coolant drops the freezing point of the engine fluid. 

At the same time, the coolant increases your snowmobile cooling system’s liquid boiling point.  In doing this, the cooling system liquid is less likely to evaporate. Now it can stick around longer and provide more cooling to the internal components of your sled. 

You shouldn’t use the same type of car or truck coolant as you would for your snowmobile. The chemical composition of sled coolant is different than that for everyday vehicles. It contains a part of water and a part of antifreeze combined. You can buy the stuff premixed or even get the parts separately and make your own snowmobile coolant if you’re up to the challenge.

If you go that route, you want to be especially careful when shopping around. You’ll notice there are two kinds of snowmobile coolant. The first is made with propylene glycol and the second has ethylene glycol. 

Propylene glycol is a type of synthetic liquid that’s especially adept at water absorption. Ethylene glycol has no color nor smell, but it’s described as having a sweet taste (not like you should ever eat it!). Besides its role in coolants, ethylene glycol is also found in manufactured polyester fibers.

You can typically tell the two types of coolants apart by the color. Most propylene glycol snowmobile coolant is orange while most ethylene glycol is green. Still, that may not always be the case, so read the label. You’re never supposed to combine polypropylene glycol with ethylene glycol. Use them separately with water only. 

What Is Fan Cooling?

Your snowmobile may have fan cooling as part of its cooling system. This is a fluid-less way to keep your engine and related components cool. As the name tells you, fan cooling uses fans within to provide consistently cool air to the motor. 

Snowmobiles equipped with fan cooling have been declared second-rate by some, but many popular sled models offer this cooling system. These include some versions of the Polaris SuperSport, the Ski-Doo MX Z 550 X, and the Arctic Cat F570. 

Which Cooling Option Is Better?

Both liquid and fan cooling snowmobile cooling systems have their advantages. A fan-cooled sled tends to cost less than one that uses liquid cooling. If your snowmobile takes coolant, then we recommend buying the separate components and mixing your own, as this is less costly than buying premixed. 

Some sled owners have also said fan cooling doesn’t need as much maintenance. Indeed, since the fans are the only part of the cooling system, you have just those to manage. With liquid cooling, the coolant could travel and get gunked up. That’s why we’ll share some liquid-cooled sled maintenance tips in the next section.

If the weather is warmer but you still want to ride your snowmobile because all the snow hasn’t yet melted, then a fan-cooled system is ideal in this scenario. Also, you may have an easier time with a fan-cooled system when you’re riding in especially hard and chunky snow, as the fans keep chugging along.

If you want torque right off the bat though, liquid cooling is the way to go. 

Maintaining a Liquid-Cooled Snowmobile

After doing a bit of investigating, you now know your snowmobile is equipped with a liquid cooling system. The sooner you become familiar with the aspects of liquid cooling care and maintenance, the better. 

Here’s what you need to do. 

Filling the Sled with Coolant

Coolant doesn’t last forever. Whether yours is made primarily with ethylene glycol or polypropylene glycol, you’ll have to fill your sled with coolant every now and again. If you’re not careful, you can make a big mess, so go slow.

Let’s say your snowmobile has next to no coolant. If so, then first, check that you mixed your coolant correctly. If you bought premixed coolant, then you can skip this step. 

Next, you want to access your sled’s coolant tank. Add a funnel or hose to the tank. Holding one hand firmly on the funnel or hose, use the other hand to pour the coolant through the funnel or hose and into your sled’s coolant tank. If you have an especially large and unwieldy jug of coolant, you might want to ask a buddy to help you with this job.

Pouring the coolant straight into the coolant system isn’t as highly recommended as using a funnel or hose. Not only can this reduce messes, but the method will parse through the air bubbles in the system so they don’t stay within. 

Next, sit on your snowmobile and run the engine. As the engine warms up, go back to the coolant tank and see if the coolant level is topped off or just a little under. Pour more coolant if the coolant tank needs it, but be careful not to overfill. 

Draining Coolant

At the end of the snowmobiling season, you’ll likely have to drain the coolant from your sled. The same can be true if you want to add new coolant and not mix it with old stuff. 

You have two ways to go about draining the snowmobile coolant. First, you can suck up the fluid with a portable vacuum that’s aimed at your sled’s cooling tank. This is efficient, although not necessarily quick.

Otherwise, you can raise your snowmobile from the front with a winch or an option of your choosing. Lifting your snowmobile like this and then accessing the cooling system from its lowest hose will allow you to use gravity to drain the old coolant. 

This option is handy, but do know you’ll never remove all traces of coolant this way. You might want to combine both methods then to fully get rid of all coolant within your sled. 

Burping the Coolant

You’re still not quite done. Some situations will call for bleeding or burping your snowmobile coolant. When you do this, you send air out of the cooling system, as too much air can cause hot spots to develop. These hot spots will keep parts of the engine particularly warm and thus make the engine prone to overheating. 

Okay, so how do you burp the coolant? First, you want to pour some coolant into your sled’s cooling tank, again with a funnel or hose. Then, as you did before, raise your snowmobile’s front end. Now, the coolant within will move, hitting the entirety of the cooling system. Any air that might be within the cooling system will be removed, although you might have to repeat this a few times.  

What to Do if Your Snowmobile Engine Overheats

Old fans or an insufficient quantity of coolant can cause your sled’s engine to overheat, as can the hot spots described above. In some cases, the problem has nothing to do with a faulty cooling system, but rather, you’ve ridden your snowmobile for hours at a time without stopping. 

In the latter situation, all you need to do is take a break for a while so your snowmobile’s engine can cool down. Outside of a long ride though, your sled’s engine should not overheat often. This is not a normal feature of a well-performing sled, and you shouldn’t treat it as such.

Continuing to ride your snowmobile when it’s overheated could cause the engine to fail if the problem is severe enough. Thus, when you feel your sled giving off more heat than it should be, you need to stop. That’s true even if you’ve only ridden for 30 minutes.

Take a look at your snowmobile’s cooling system. Are the coolant levels lower than they should be? Does your motor have enough fuel? Is the compressor in good shape? If you answered no to these questions, that’s not a great sign. 

Some snowmobilers will install a rear fan at the radiator to regulate the temperature of their sled over longer rides. You can try this or bring your sled into your favorite repairperson to get it assessed and possibly fixed. 

Final Thoughts 

Snowmobiles are cooled one of two ways: with a fan system or through coolant, a type of liquid cooling agent. Both are great ways to prevent your sled from overheating, but if that happens, you can’t ignore the issue. For the sake of your engine’s longevity, it’s best if you stop riding right away, see a repairperson, and get the issue taken care of. Good luck! 

Geoff Southworth

I am a California native and I enjoy all the outdoors has to offer. My latest adventures have been taking the family camping, hiking and surfing.

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