How to Check & Change Engine Coolant

Steps on replacing Engine Coolant

Engines get hot. Like, really hot. It’s the radiator’s job to regulate the engine’s temperature and act as a cooling system to keep it from overheating, but it can’t do its job without engine coolant. Vehicle coolant is also known as antifreeze because it keeps the liquid in the radiator from freezing once the temperature gets down to a freezing point. Just like you need to check and refill your motor oil to prevent corrosion, you'll want to make sure your coolant level is always good to go too. Check out the following tips for checking and refilling your car’s coolant.

Check Your Coolant Level

Locate the coolant reservoir under the hood of your vehicle. It should be a transparent little tank with minimum and maximum lines shown on the side. If the level is below the minimum line, you will need to add coolant to keep your car and radiator happy. If your engine is starved of coolant it will overheat in a matter of minutes, which usually causes irreversible and expensive damage.

Running low on coolant is a problem.

Pick the Right Kind

Like an assortment of delicious popsicles, engine coolant comes in several different colors and types (oat antifreeze, coolants with acid technology, dex cool, coolant antifreeze with and without silicates or propylene glycol, etc.). Unlike an assortment of delicious popsicles, you should never taste test engine coolant. That’s a horrible idea. Keep it out of reach of children and pets, too. Antifreeze or performance coolant is made of a substance called ethylene glycol that has a sweet taste to it. The Humane Society warns that the smell and taste of antifreeze are appealing to cats and dogs, so it’s important to store coolant properly and clean up any spills.

With that public service announcement out of the way, let’s talk about choosing your coolant. It’s important to check which kind is currently in your vehicle so that you can refill it with the same formula. Mixing different types can damage your engine, so be careful. It’s even worse than that time a waiter came and topped off your Coca Cola with iced tea on accident.

Wait for Your Engine to Cool Down

Refilling the fluid antifreeze or coolant is something you should only do when the engine is cool. Don’t attempt to handle this right after the vehicle has been driven. Coolant systems are pressurized, which means the reservoir is very dangerous to open while it’s hot. Just wait until the engine is cool. Carefully open the reservoir cap and add the coolant until it reaches the fill line. Many coolant solutions are ready to use, but check the bottle in case it’s a concentrated formula that must be mixed with distilled water first. On that note, never put plain water in your coolant reservoir unless it’s an emergency.

If you check your coolant reservoir while the engine is hot, it could explode.


Check your owner’s manual to find out how often you should get your engine coolant flushed and replaced. If it seems like you have to refill your coolant often, there may be a problem with your vehicle. Take it to the mechanic for servicing as soon as possible. If there is a leak somewhere, you want to know about it and get it fixed.

Remember the importance of a reputable mechanic.

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