Can You Put Water Instead of Coolant

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If you’re a normal person like me and most other folk, you probably don’t have coolant at hand very time when your car’s radiator has low levels or the engine has been running hot for elongated levels of time and just simply needs a top off. In such cases, you must have wondered to yourself, can You put water instead of coolant. 

The answer to that is a resounding yes, you can put water in your car’s radiator instead of coolant and it will work fine – for a while, at least. Ideally, you’ll want to replace the water with coolant as soon as possible, but if you’re in a bind or just forgetful like me, know that water will do the job in a pinch. Just be careful not to let the engine overheat too much or you might have bigger problems on your hands!

In this article, we will explore the reasons why we use coolant instead of water in the first place and different types available too so you can make an informed decision next time you find yourself in this situation. 

Can You Put Water Instead Of Coolant?

As mentioned above, you can put water in your car’s radiator instead of coolant, but it’s not recommended to do so for long-term use. The main reason for this is that water doesn’t have the same cooling or antifreeze properties as coolant, which is specially formulated to protect your engine from damage. In a worst-case scenario, if your engine overheats with water in the radiator instead of coolant, you could end up with a seized engine.

However, if you’re just topping off your car’s radiator and don’t have any coolant on hand, water will do the job in a pinch. Just make sure to replace the water when you can. 

Coolant vs. Water – What’s the Differences?

Valvoline Multi-Vehicle 50/50 Prediluted Ready-to-Use Antifreeze/Coolant 1 GA

CRYSTAL GEYSER SINCE 1977 Purified Water 1 Gallon, 25.4 Fl Oz, (Pack of 2)

The differences between the two are mainly in terms of cooling and antifreeze properties. Coolant has been specifically formulated to protect your engine from damage due to extreme temperatures, whether that be hot or cold. It also helps to keep the system clean and prevents corrosion. Water, on the other hand, doesn’t have these same properties and can actually cause faster wear and tear to your engine.

That being said, water is still an effective coolant as long as it’s not left in the system for too long. In a bind, it’s better to put water in your car’s radiator than no fluid at all. So, you most certainly can put water instead of coolant if needed. The following is more detailed information on the differences between coolant and water. 

1. Boiling Point

Water has a boiling point of 100 degrees Celsius, while coolant has a boiling point higher than that – typically around 110-120 degrees Celsius. This is important because it means that water will start to boil and turn to steam much sooner than the coolant, which can cause the engine to overheat.

2. Freezing Point

The freezing point of water is 0 degrees Celsius, while the freezing point of the coolant is much lower – typically around -35 to -40 degrees Celsius. This means that water will freeze faster than the coolant, which could potentially damage your engine if it’s left in the system for too long as ice can cause blockages inflow leading to overheating.

3. Corrosion Protection

A unique and special property of coolant is that it contains inhibitors that help to protect the engine from corrosion. Water doesn’t have this same property and can actually cause accelerated corrosion to metal parts in the engine. Coolant also helps to keep the system clean, while water can cause build-up and deposits over time as the water evaporates.

Also Read: How to tell if your Coolant Temp Sensor is Bad

What is Coolant or Antifreeze?

Valvoline Multi-Vehicle 50/50 Prediluted Ready-to-Use Antifreeze/Coolant 1 GA

Antifreeze is a specialized type of coolant that contains additives that help to protect the engine from damage due to extremely cold temperatures. Without antifreeze, water can freeze in the system and cause serious damage to your engine. It is known to be a colorless, odorless liquid that helps to lower the freezing point of water. 

Antifreeze is typically a mixture of propylene glycol and water, and is available in both pre-mixed and concentrate forms. It can withstand temperatures as low as -60 degrees Celsius without freezing and is often used in cars, trucks, motorcycles, boats, and other vehicles. 

Different Types of Coolant

The following are some of the most common types of coolant:

1. Inorganic Acid Technology (IAT)

As it sounds, this type of coolant uses inorganic acids (such as phosphates) as the main ingredient. It’s popular because it has a long life and is effective at both high and low temperatures. It is most commonly used in older vehicles and has a green color. Should be changed every 2 years or 30,000 miles.

2. Organic Acid Technology (OAT)

This is a newer type of coolant that uses organic acids (such as esters) as the main ingredient. It’s also popular because it has a long life and is effective at both high and low temperatures. It is most commonly used in newer vehicles and has an orange or even dark green color. Should be changed every 5 years or 100,000 miles.

3. Hybrid Organic Acid Technology (HOAT)

A more recent development, HOAT is often orange or yellow. It’s a unique formulation that’s made specifically for new cars and includes additions to enhance aluminum corrosion resistance and prevent rust. Like OAT coolants, HOATs have a lifespan of 150,000 miles or 5 years.

Benefits of Using Water Instead of Antifreeze

The only few benefits of using water instead of antifreeze are the following: 

1. It’s readily available and easy to find – you can get water almost anywhere.

2. It’s cheap – you can usually get a gallon of water for less than a dollar.

3. It doesn’t contain any harmful chemicals or additives.

Bad Effects of Using Water Instead of Antifreeze

The cons of using water instead of antifreeze are as follows: 

1. It doesn’t have the same cooling properties as antifreeze, so it can’t cool the engine as effectively.

2. It has a lower boiling point than antifreeze, so it can cause the engine to overheat more quickly.

3. It can freeze faster than antifreeze, leading to engine damage.

4. It doesn’t contain any inhibitors to protect the engine from corrosion like antifreeze does.

5. Water can cause build-up and deposits over time as it evaporates, while antifreeze helps to keep the system clean.

FAQ

Will a car overheat with just water?

In comparison to coolant, water does not have the same cooling properties and if used in a car without antifreeze in below zero temperatures, can cause the engine to overheat more quickly.

Does coolant stop rust?

Rust can form on the metal parts of an engine whether or not coolant is used, but the inhibitors in coolant help to prevent it from spreading and becoming more severe. Without these inhibitors, corrosion will be more likely to occur and can cause serious damage over time.

Why is my coolant orange?

Coolants can come in a variety of colors, but the most common are orange and green. The color usually indicates the type of coolant – IAT (green), OAT (orange), or HOAT (yellow). Each type has a different lifespan and needs to be replaced at different intervals.

Conclusion 

So there ya have it – the pros and cons of using water instead of coolant in a car. In the end, it’s up to the individual to decide what’s best for their vehicle. While water may be cheaper and more readily available, coolant has a number of benefits that make it a better choice for most drivers.

This is mainly due to its ability to cool the engine more effectively, as well as its anti-freeze and inhibitor properties. As always, it’s important to consult with a mechanic if you’re not sure which type of coolant is right for your car. Thanks for reading!

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