No Antifreeze in Car Just Water: Is That OK? (Explained!)

You might be driving down the road, and you notice that your temperature gauge is starting to shoot up, and in this case, you will need antifreeze. But will water do? Let us find out. 

So is it okay to have water in your car and no antifreeze? The answer is that it depends on the vehicle and the scenarios. 

Many owners have been asking this question. Let us learn more, so keep reading. 

No Antifreeze in Car Just Water

Can I Run A Car With Just Water?

Way back, vehicles are still simple. Years ago, vehicles could run with just water on their radiators. People will add antifreeze if it gets cold. 

If you run water in your car’s radiator, it can now cause overheating and damage. Tap water has minerals, and these minerals will leave deposits inside the radiator. It can cause corrosion, and it will then shorten the life and lower the ability of the vehicle to cool down. 

Coolant has a protective coating on your radiator, and this will inhibit corrosion. A 50/50 mix of coolant and water will also lessen the freezing temperature and raise the boiling point of the water in your vehicle’s radiator. So if you find yourself in a situation where you do not have antifreeze and only have water, make sure that it is for a short distance only. 

Can I Use Water If I Have No Coolant?

Yes, you can use water if you do not have coolant. Make sure that it is for emergencies only. Just know that this is not recommended. 

This is because the water will not work very well if it is beyond freezing and boiling point. It can also result in considerable damages to your engine. 

So make sure to do so in emergencies. Make it a habit and check the coolant level and cooling fan to avoid problems in the future. 

Will A Car Overheat With Just Water?

If you run your vehicle with just water in the radiator of your vehicle, it will guarantee overheating and engine damage. This will include the cylinder heads of your vehicle and engine block. 

Most of the tap water also has minerals, and it can leave deposits in your radiator. It will create corrosion and will shorten the life of your cooling system. 

Can You Drive A Car With Just Water In The Radiator?

Water can put contaminants in your radiator system. This is much better for your engine because it has water and it can drive low coolant. You must also replace the water with the proper coolant for your vehicle as soon as possible. 

If you add water to your radiator, you will dilute any coolant that is still in the radiator. Coolant has so many vital functions. It can prevent corrosion, increase the boiling point of the water, and lower the freezing point of the water. 

If you drive for only a short time with water, then it may do, but it will not protect your engine. That means that you have to know the problem causing a low coolant level and fix it as soon as possible. 

Why Should You Not Top-Up Coolant With Just Water?

You can top up your coolant with water, but you should only do it during emergencies, and you are in a situation where you have no choice. The engine coolant has antifreeze, and so diluting water will then lessen and lower the boiling point. The coolant will then stop working. 

car with just water and no antifreeze

Can You Use Water Instead Of Coolant In The Summer?

You can use plain water in your cooling system, but it is not recommended for a long-term solution. It is also not recommended for extreme weather conditions. If you use water in your cooling system, the water will then freeze in 0 degrees celsius. 

In winter conditions, the water will be untreated. In the summer, if you do not put antifreeze, your coolant system will decline and have bad results for your engine. 

What Happens If You Put Water Instead Of Coolant?

Putting water instead of coolant can cause you problems. The job of the coolant is to remove any heat away from your engine. 

This is a product of a combustion process. This is natural for the coolant to heat up during the process. 

Can Using Water Instead Of Coolant Cause Overheating?

Yes. It can also deliver a lot of severe damages to your engine. If you use water instead of coolant, the high temperatures inside your motor will boil quickly and cause evaporation. 

This means that you will quickly have no coolant at all. The engine will also overheat quickly. 

Why Do We Use Coolant Instead Of Water?

If you use coolant in your vehicle’s engine, it can increase the boiling point of the water. This means that your vehicle will not run any longer without overheating. 

This can also work to lower the temperature, and the water will freeze. The coolant will keep the liquid cool inside your engine. 

Can I Use Water Instead Of Coolant In An Emergency?

Using water instead of coolant will not do the job of the coolant. It has no boiling point or freezing point range. Therefore, it cannot protect the engine of your vehicle. 

It will also not absorb heat effectively. If you are in an emergency, you can use water in your coolant rank. 

Disadvantages Of Using Water As Coolant

These are the disadvantages of using water as a coolant.

1. There Will Be Cavitation And Erosion.

There will be vapor bubble formation, and it is known as cavitation. The cavitation will happen if there is a pressure drop, and this can lead to overheating. It can also lead to damages. 

2. There Will Be Compromised Combustion.

The engine will suffer from overheating around the combustion zone. As a result, there will be a compromise in the combustion. 

The fuel-air mixture will then detonate or pre-ignite. The detonation will reduce the power as the charge and then ignite while the piston rises in the cylinder. 

3. There Will Be Pressure Stresses.

The water-based antifreeze will cause a high vapor pressure. This will create corrosion over time. 


In summary, antifreeze is essential to the engine. Every vehicle needs antifreeze. It can prevent overheating and prevent wear and tear in your engine. 

There are times where you do not have antifreeze, and you only have water in you. That is okay if it is an emergency. Otherwise, do not do it.



Image credits – Canva

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My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more