Skip to content
  • Home
  • Autos
  • Audio
  • Bikes
  • Batteries
  • Detailing
  • Oils
  • Parts
  • Questions
  • Roof Boxes
  • Scanners

Can You Put Water in The Car Radiator?

Written BySteve Riley
Can you put tap water into a car radiator
Photo by Nathan Marquardt

Is It Safe To Put Normal Tap Water Into The Car Radiator

Yes it is safe. This should only be done in an emergency when you are low on water and a light has come on telling you so.

Table of Contents
  • Is It Safe To Put Normal Tap Water Into The Car Radiator
  • How the radiator works
  • Benefits of using a coolant for your car
    • Heat absorption
    • Freeze protection
    • Prevent engine rust
    • Signs that your radiator is failing
    • Engine overheating
    • Low coolant levels
    • Sludge buildup in the radiator
    • Contaminated coolant
  • Conclusion

NEVER open a hot radiator cap. It lets off steam and could cause you serious burns from coolant blowback. ALWAYS wait until the engine has cooled down, at least 200 minutes before you release the radiator cap.

Your car’s radiator is one of the most important components of your car. The normal internal combustion engine produces a lot of heat which when not controlled can cause serious damage to your engine's internal components. The radiator plays an important role of heat dissipation.

03/10/2023 9:31 am
  • Valvoline Multi-Vehicle 50/50 Prediluted Ready-to-Use Antifreeze/Coolant 1 GA, Light Yellow/Green.
    Valvoline Multi-Vehicle 50/50 Prediluted Ready-to-Use Antifreeze/Coolant 1 GA, Light Yellow/Green.
    • CONTAINS ALUGARD PLUS FOR COMPATIBLITY WITH ALL ETHYLNE GLYCOL-BASED COOLANTS in automobiles and light duty trucks.Fit Type: Universal
    • FIGHTS CORROSION, SCALING AND RUST while protecting all cooling system metals (including aluminum)
    • HIGH-QUALITY ADDITIVES PROTECT AGAINST LEAKS and won’t harm gaskets, hoses, plastics or original vehicle finish
    • PRE-MIXED YELLOW
    $ 14.83 -7%
  • PEAK OET Extended Life Violet 50/50 Prediluted Antifreeze/Coolant for European
    PEAK OET Extended Life Violet 50/50 Prediluted Antifreeze/Coolant for European Vehicles, 1 Gal.
    • 1 GALLON ENGINE ANTIFREEZE/COOLANT: Fully compatible with other extended life antifreeze/coolants. This item contains a bittering agent called Denatonium Benzoate.
    • PROTECTS: Advanced formulation prevents rust & corrosion protecting all cooling system components
    • DESIGNED FOR EUROPEAN VEHICLES: Recommended for use with certain years of Audi, Mercedes, Porsche, VW, and
    $ 18.95

When your radiator fails, your engine starts overheating. You will notice that the temperature dials on your dashboard rise up. If you do not stop the car at this moment it will shut off itself further causing more damage.

How the radiator works

Part of the radiator system is a thermostat that constantly checks the coolant temperature. The combustion process is intensive, coupled with the constant friction of metallic elements a lot of heat is generated.

The thermostat will be constantly monitoring the engine's internal temperature. The moment it notices a peak, it allows the flow of water and the coolant to the engine parts. The coolant will pick the heat from the engine hence cooling it. This hot coolant is passed to the radiator where it is later cooled.

The radiator has some air vents which cools the hot coolant as it passes by. This process of cooling the hot engine is constant but there moments the process fails.

Firstly, if your thermostat fails, it will not release the coolant at the right time, leading to the engine overheating. There are also cases when the coolant system develops leaks or becomes clogged, preventing the efficient flow of coolant along the engine system.

Benefits of using a coolant for your car

The coolant is an essential component for efficient engine performance. At its basic level, most coolants are made from a mixture of ethylene glycol and distilled water. You will also have motorists referring it as an anti-freeze agent.

The color varies depending on the manufacturer with most of the coolants being either green or orange. You will find the coolant container near the radiator block. The coolant container has minimum and maximum levels.

The radiator has grills at the front that are used for heat dissipation, it also works together with the car fan. When you start driving the internal combustion starts generating heat in the engine.

The coolant and distilled water circulate through the engine block hence helping in heat dissipation. This hot coolant is then passed to the radiator where the air vents cool it and it is re-circulated to the engine block again.

Heat absorption

The first task of the coolant is heat dissipation. Since it has a high boiling point, it works better in heat dissipation than normal water. The internal combustion engine ignition of the air/fuel produces much heat.

This heat when not transferred from the engine block can cause further problems. The thermostat is the one responsible for heat regulation in the radiator.

Freeze protection

Coolant is used instead of water because it has a low freezing point. This is handy for people living in places with extreme winter temperatures. Water would solidify making it useless in engine heat dissipation.

This would cause further damage to your engine block as water turns into ice. Solidified water puts more pressure on your engine block as it expands. The coolant does not suffer from this problem and maintains its viscosity regardless of engine temperature.

Prevent engine rust

Water can cause corrosion on the various metallic components in your engine. But, the coolant won’t hence its preference to water for engine heat dissipation. You should change your coolant regularly as it succumbs to electrolysis and becomes acidic.

When this happens the acidity starts interacting with your engine metallic parts causing further problems. You should check the coolant container to know how frequent you should change your coolant. Most motorists flush out the coolant after every 50,000 miles. Also, know that the coolant is extremely poisonous and should not be swallowed.

Signs that your radiator is failing

The radiator is an important component for efficient engine performance. It helps in heat dissipation. But, how does one tell that the radiator has stopped working or the coolant is leaking.

Engine overheating

Under normal conditions, your engine cooling system will keep your engine cool but when it fails it your engine overheats. This is a clear sign that your radiator is failing.

This is often accompanied by the engine temperature gauges on the dashboard going up. Sometimes the solution can be as simple as refilling your coolant but if the gauge continues going up it means that the radiator is not cooling your engine.

The normal operating temperature for the engine is usually 195 to 220 degrees. Anything higher than this is a symptom of engine trouble. However, do not worry so much if it rises during extremely hot summers.

Low coolant levels

Once you notice that the temperature gauge keeps rising, the next step is to check your coolant levels. There is an indication of maximum and minimum levels. If you notice that every time you add the coolant it keeps going to minimum levels then you could be experiencing a leak. You can check underneath your car engine for signs of leaks. A leaking coolant is identified by its bright color mostly a green or orange color.

Sludge buildup in the radiator

The radiator system is run through several pipes that help push hot coolant from the engine to the cooler radiator parts. When these pipes become clogged then the safe passage of the coolant is hindered.

One of the reasons for a clogged radiator system is when you use a cheap coolant. The radiator fins are metallic in nature and with time they develop rust. This rust coupled up with a cheap coolant leads to clogging of your radiator. Rust will also develop when you use normal tap water instead of distilled water for your radiator.

When you have a clogged radiator system the only solution is to flush out the cheap coolant and normal water. This will take care of the impurities in the system.

Contaminated coolant

Most coolants have a bright green or yellow color. It also has a high viscosity and flows freely through the radiator system. However, the engine has many deposits, which contaminate the coolant. This makes it less fluid and changes its color to a darker one.

If you do not replace the coolant at this point, it will clog up your radiator system, leading to the engine overheating. The radiator fins are small and subject to more frequent clogging.

Since the fins are the ones that bring in cool air to the radiator they are subject to contamination by dirt, leaves and other airborne materials. To clean the fins you may need to dismantle the radiator system and clean it with a spray nozzle. Other times the radiator fins are bent and in need of re-alignment.

Conclusion

The radiator is one of the most vital components in cooling your engine. The enormous amounts of heat generated through the internal combustion process is very high and if the engine is not cooled in time it will lead to further damage to the engine components.

Coolant is used instead of water in the radiator due to its high boiling point and low freezing point. You identify the coolant by its bright green or orange color.

03/10/2023 9:31 am
  • PEAK OET Extended Life Orange 50/50 Prediluted Antifreeze/Coolant for North
    PEAK OET Extended Life Orange 50/50 Prediluted Antifreeze/Coolant for North American Vehicles, 1 Gal.
    • 1 GALLON ENGINE ANTIFREEZE/COOLANT: Fully compatible with other extended life antifreeze/coolants. This item contains a bittering agent called Denatonium Benzoate.
    • PROTECTS: Advanced formulation prevents rust & corrosion protecting all engine cooling system components
    • DESIGNED FOR NORTH AMERICAN VEHICLES: Recommended for use with Ford, Chrysler, and GM vehicles that
    $ 18.95
  • Mopar 10 Year/150,000 Mile Coolant 50/50 Premixed
    Mopar 10 Year/150,000 Mile Coolant 50/50 Premixed
    • Package Weight: 4.227 kg
    • Product Type: Auto Part
    • Package Quantity: 1
    • No Batteries Required
    • Embittered - Contains Bittering Agent
    $ 22.75

Related posts:

Default ThumbnailCar cooling system: Which is better – coolant or water? Engine coolant issuesDisposing of Engine Coolant – How To Dispose Appropriately how-to-mix-concentrated-antifreeze-with-water-2How to mix concentrated antifreeze with water
Post Tags: #Car Cooling
engine-oil-check-proper-way-to-check-oil-how-often-to-check-oil
Oils

Motor Oil Precautions, Safety Measures and Handling

Motor oil precautions, safety and handling. Clean motor oil ensures your engine runs smoothly and efficiently. Always discard safely, and handle...
Read More Motor Oil Precautions, Safety Measures and Handling
14/03/2020
Categories Oils
foxwell-nt630-vs-nt644-finding-the-right-tool-for-your-automotive-diagnostic-solutions-2
Scanners

Foxwell NT630 vs. NT644 – Finding the right tool for your automotive diagnostic solutions

Foxwell NT630 vs. NT644 Owning a car can be stressful especially when you don’t know why...
Read More Foxwell NT630 vs. NT644 – Finding the right tool for your automotive diagnostic solutions
25/07/2022
Categories Scanners
TagsFoxwell, OBD Scanners
Maximizing Storage for Your BMW 5 Series: A Roof Box and Rack Buying Guide
Roof Boxes

Maximizing Storage for Your BMW 5 Series: A Roof Box and Rack Buying Guide

If you own a BMW 5 Series and are planning to take a road trip, you may need some extra...
Read More Maximizing Storage for Your BMW 5 Series: A Roof Box and Rack Buying Guide
10/03/2023
Categories Roof Boxes
TagsBMW
Clutch adjustment and biting point
Questions

High Clutch vs Low Clutch Understanding How Clutch Adjustment Works

High Clutch vs Low Clutch. A high clutch normally indicates that your clutch plate is on its last legs. Learn...
Read More High Clutch vs Low Clutch Understanding How Clutch Adjustment Works
13/09/2021
Categories Questions
TagsClutch
Autos

What Are The Most Common Jeep Problems?

While Jeeps are popular vehicles, they are not exactly perfect. Take a look at common complaints...
Read More What Are The Most Common Jeep Problems?
23/02/2021
Categories Autos
TagsJeeps
driving-an-old-car-what-are-the-risks-and-challenges-involved
Autos

Driving an old car: What are the risks and challenges involved

What Are The Riska Of Driving An Old Car Vehicle safety is a crucial factor when...
Read More Driving an old car: What are the risks and challenges involved
24/05/2022
Categories Autos
TagsCar Tips

Affiliate Disclosure

We are an affiliate. We hope you like our recommendations! Just so you know, we may collect a share of sales or other compensation from the links on this website. Thank you for using our links, it helps to grow our website.

  • Privacy Policy
  • Affiliate Disclosure
  • Contact Us
  • About Us
  • Cookie Policy
  • Privacy Statement

© 2023 MotorBeast Motorbeast.Org

Manage your privacy

To provide the best experiences, we and our partners use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us and our partners to process personal data such as browsing behavior or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.

Click below to consent to the above or make granular choices. Your choices will be applied to this site only. You can change your settings at any time, including withdrawing your consent, by using the toggles on the Cookie Policy, or by clicking on the manage consent button at the bottom of the screen.

Functional Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
Statistics

Marketing

Features
Always active

Always active
Manage options Manage services Manage vendors Read more about these purposes
Manage options
{title} {title} {title}
Manage your privacy
To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behavior or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Functional Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
Manage options Manage services Manage vendors Read more about these purposes
Manage options
{title} {title} {title}
Scroll to top
  • Home
  • Autos
  • Audio
  • Bikes
  • Batteries
  • Detailing
  • Oils
  • Parts
  • Questions
  • Roof Boxes
  • Scanners
Search