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How to Check Coolant Level: A Simple Guide 

How to Check Coolant Level: A Simple Guide 

Checking the coolant in your vehicle can save you a lot of money and problems in the long run. If your car overheats, the number of components that can break down on you can be pretty staggering. Keeping your coolant levels topped up and working properly means you're going to avoid all that and you'll be able to enjoy your vehicle much longer. 


 

Checking your coolant only takes a few moments of your time, so there's no reason not to get this done considering all the potential benefits. We recommend checking your coolant levels every time you stop to gas up. If that seems excessive, just think of how excessive a repair bill is when you need to get a cracked cylinder head replaced because your engine overheated. That kind of repair bill is going to cost you around $500 to $1,000. So what seems worse to you, spending that money on engine repairs, or just checking your coolant levels on a regular basis? It's a pretty easy call.

 

If that’s just too excessive for you then having a regular schedule for checking your coolant is a good idea as long as you stick to it. Some mechanics recommend checking your coolant before seasonal extremes. That means before it gets hot and before it gets cold or at the beginning of summer and winter. Others recommend at the beginning of every season so four times a year at the beginning of fall, spring, winter, and summer. Whether you want to check it very frequently or semi-regularly, you still should be doing it at least several times a year at a bare minimum.

 

What Does Coolant Do in My Car?

 

The name coolant makes it seem pretty obvious exactly what coolant does in your vehicle. It keeps things cool. Ironically, it also does the exact opposite as well. It stops things from freezing which is why coolant is also known as antifreeze. It's a dual-purpose chemical that essentially balances the temperature in your vehicle between two extremes.

 

Coolant travels from your radiator through the engine once your engine heats up and absorbs the excess heat so that it can stay within an optimal temperature range. An overheated engine could potentially cause catastrophic failures for your car. And, though this is far less common, a vehicle that is too cool can also cause some issues as well by not being able to get up to operating temperatures. You need to stay in the exact range your vehicle was designed for in terms of temperature. Keeping your coolant levels topped up ensures that happens.

 

Checking Coolant Levels the Right Way

 

One thing you never want to do is check your coolant when your car is running. Although you can look at the overflow tank in your engine when your vehicle is still warm and get an idea for the levels, you never want to open your radiator when your vehicle is running or has recently been operating. Coolant, because of the temperatures that it operates at, is very dangerous. If you were to open your coolant tank when your engine was still hot you could potentially cause a very serious burn. So, keep that in mind. Anytime you are going to take the cap off to top up your coolant levels or you don't have an overflow tank because you have an older vehicle and you need to actually look inside the radiator, only do it when your engine is cold.

 

The easiest way to check coolant, as we just mentioned, is to check the plastic overflow container that is connected to the cooling system. It's translucent white plastic and will have a brightly coloured cap of some kind on top of it. You can see from the outside the markings on the side of the bottle. These indicate the maximum and minimum fill levels. The shadow of the coolant should be visible inside the bottle and ideally is going to fall in between the maximum and minimum levels. This is a safe and easy way to check the coolant and doesn't even require you to open anything. However, if you're seeing that your levels are below the minimum, then you're definitely going to need to add some more coolant to the system.

 

The only issue with doing a quick visual check out of the overflow tank in this way is that you're not able to determine the quality of the fluid just the volume. If you're looking to determine whether or not you have any kind of contamination in your coolant then you're going to actually need to open the tank and take a look. Again, this can only be done with a cold engine in order to prevent serious injury. Additionally, if you have an older vehicle that doesn't have that coolant reservoir, you need to remove the cap to take a look at not just quality but quantity.

 

Signs That the Coolant Level is Low

 

If you're not checking your coolant very regularly, there are some signs that can let you know you need to get it checked out sooner rather than later.

 

 High Temperatures

 

Obviously if your engine is running hot then that's a sign you have a problem with your cooling system. If the temperature gauge on your instrument console is constantly running into the red, then your first order of business should be to check out your coolant levels to see if that's the problem. Your engine can only run hot for so long before serious damage occurs.

 

Coolant Smell

 

One of the easiest ways to notice a coolant leak in your system somewhere is because of the smell it produces. Antifreeze has a very distinctive sweet odour that is hard to mistake for everything else that you use in your car. That's part of the reason why coolant is so dangerous as animals and sometimes people will be tempted to drink it. However, antifreeze is extremely toxic which is why it needs to be handled with care and if you have a leak you need to get it fixed as soon as you can. If you're noticing that sweet smell in the cabin of your vehicle, you likely have a leak in the line somewhere that you're going to need to get fixed.

 

Poor Gas Mileage

 

As unexpected as it may be, your gas mileage may suffer if your coolant levels are low. This is because when your engine runs hot you start burning fuel much less efficiently. As a result, you're going to have to head to the gas pumps more often even though you're not seeing any boost in performance.

 

 Coolant Light

 

If the coolant light on your dashboard pops on, then that's obviously a sign that you have a problem with your cooling system in some way. The coolant light looks a bit like an old-school thermometer with some wavy lines around it. It's there to alert you to the fact that your engine is hitting a critical temperature and you need to shut it down as soon as you can. If this were to happen while you were driving on the highway, then your first course of action should be to safely get off the road and pull over as soon as possible. Generally speaking, this indicates a leak somewhere in your system.

 

 

Does My Coolant Reservoir Need to be Full?

 

 While having a low coolant level is obviously a danger for your vehicle, when we talked about having a full coolant reservoir it should be made clear that doesn't mean that your coolant levels have to rise to overflowing. Remember that your coolant is subject to high pressure and high heat and it will expand considerably when your car is running. At a standstill, when your car is cool, your coolant reservoir is probably only going to be about 30% full. That's exactly what you want. If you overfill it, it could cause some serious damage.

 

 Can You Mix Coolant Colors?

 

It's a very bad idea to mix different kinds of coolant in your vehicle. Typically, coolant comes in two different colours. There is green coolant which is your traditional glycol-based antifreeze and there is also an orange coolant which is also made from ethylene glycol but there are additives in it that increases its lifespan in your vehicle.

 

Typical green antifreeze is usually mixed 50/50 with water in your radiator. This kind of coolant has a lifespan of around 3 years or 36,000 miles or so before you'll need to replace it. Orange antifreeze, sometimes known as Dexcool, has a lifespan of 150,000 miles or so.

 

Aside from these two most common coolant colors there are actually an entire rainbow of other colours available on the market. You can get antifreeze in blue, yellow, pink, gold, and so on. Many of these are formulated for specific vehicle types. For instance, yellow antifreeze has been formulated to work with Kia and Hyundai vehicles. One kind of blue antifreeze is designed for Acura, Honda, and Subaru vehicles. Some of these are meant to last up to about five years as well.

 

The problem with mixing colours of antifreeze in your vehicle is that the formulations will not be the same. That can cause some major problems in how your vehicle operates. For instance, if you mix the most common types, the green and the orange, what you're going to do is create a gel in your radiator. It will thicken up and not flow properly. This can cause severe overheating of your engine and require a complete radiator flush to clean out. For that reason, you want to make sure you know exactly what kind of coolant you have in your engine before buying new stuff and adding it. 

 

 How Do You Refill Coolant?

 

The process of adding new coolant to your vehicle is not very hard at all. Just remember to make sure you know exactly what kind of coolant you should be using before you add any to the tank to prevent damages. And of course, you need to do this with a cold engine and not a running or still hot engine.

 

Step 1: Locate the coolant reservoir that we mentioned earlier and check the level of your fluid. If you're needing to refill it, it's obviously going to be somewhere below the cold fill line.

 

Step 2: Loosen the cap on the reservoir a small bit. The system is likely under a bit of pressure so, just like when you take the cap off of a bottle of soda, you might get a hiss of pressure release when you loosen this. That's why you loosen it just a bit and let the pressure release. Once that's done you can remove the cap.

 

Step 3: Add the coolant to the tank. How you add this depends in some way on what kind of coolant your engine requires. If you have a pre-mixed coolant already then you can just pour it into the reservoir until you reach the max fill line. If you're just using something like antifreeze, then you're going to need to mix it 50/50 with distilled water. Make sure it's distilled water you're using, not bottled water or tap water. Those can cause buildup and contamination in your system.

 

Step 4: Once you reach the maximum fill line you just need to replace the cap and tighten it again. That's all there is to it and your coolant is now refilled.

 

The Bottom Line

 

Checking the coolant levels in your vehicle is a simple job that really requires no more than a moment to observe the tank and see where the fluid level is. Doing so can very much help to ensure that your car stays working at the optimal temperature it should be at and avoiding serious damages and repairs that can come from an overheating vehicle. Once you get in the habit of checking your coolant levels on a regular basis, it shouldn't be a problem at all and will give you the peace of mind of knowing that you're not going to have an overheating engine sneaking up on you anytime soon.