Cars are an indispensable part of our lives and require constant care and attention. A well-maintained car can last a lifetime!
For a car to be healthy, its engine and radiator should be in top shape. One DIY car maintenance project you can do is flush out the radiator using a radiator flush.
A radiator flush is designed to drain oils, debris, dust, contaminants and pollutants trapped within your car’s radiator. These can damage your car in the long run and should be cleaned out regularly!
In this article, we will count down 10 of the best radiator flush cleaners you can order for your car.
In hurry! Then here is our top 3 radiator flush for you.
- Irontite ThoroFlush – Best Radiator Flush 2021
- BlueDevil Products Radiator Flush – BEST OVERALL
- Design Engineering 040200 Radiator Relief – BEST VALUE
The Best Radiator Flush Reviews
Now that you know what a radiator flush can do, it is time to get one for your car, but not before looking at our top radiator flush picks for 2021!
BlueDevil Radiator Flush – BEST OVERALL
The Bluedevil radiator flush can flush out engines by removing rust, gunk, oil and grime. It is a good flush suited for a variety of engines. It is especially recommended for high mileage engines that tend to clog up faster.
Flushing your system using the Bluedevil radiator flush can help your engine function well for years. This flush has advanced cleaning powers designed to cut through the toughest of pollutants and contaminants.
It is a concentrated formula meant to clear out years of build-up and restores your engine. 16 quarts of this can be used in one go. You can use more if the build-up is too rigid.
- This flush is specially formulated for high mileage vehicles
- Will also do well with regular engines
- Improve the performance of the vehicle
- Designed to clear the engine within five minutes
- Helps to extend engine longevity
- Advanced cleaning powers and a concentrated formula
Irontite ThoroFlush 468-9110-16- Best Radiator flush Cleaner – Best Radiator Flush 2021
The Irontite Thoroflush is a great option for those looking to clean out old, rusty radiators. It is a powerful flush that removes hard residues and completely clears out the flush system. A lot of debris and contaminants get trapped in the fuel tank over a period of time and end up as fine particles that are tough to dislodge.
This flush will help you remove these particles and clear out the radiator. It can save you a lot of money, as getting it professionally cleaned out can cost a bomb! A single pint of this flush will remove scale, rust and ethanol gel and other residues.
Let the flush sit for less than five minutes and watch all the contaminants dissolve and flush out of the system.
- Powerful, concentrated radiator flush ideal for high mileage engines
- Can also be used with regular engines
- Quickly loosens rust, oil, sludge and grease
- Best suited for high density vehicles such as trucks
- Safe to use with plastic, aluminum and iron
Our next pick is the Zerex super radiator flush, designed for HD diesels. These engines tend to clog up easily and require flushing systems that can cut through thick deposits of engine oil.
This flush will do a good job and get through such deposits. Coolant systems tend to mix with engine oils and turn muddy. These should be flushed out for the engine to function optimally. The Zerex radiator flush will drain all of it out within five minutes.
The flush is used to clean out plugged heater cores and also removes coolants in a single flush. It is safe to use with aluminum, iron, plastic and brass radiators. This flush is one of the most powerful in the market, so make sure you do not allow it to sit in for more than five minutes, as otherwise it can damage your car.
- Works superfast and flushes out built up gunk and oils from radiators
- Ideal for a variety of cooling systems including plastic and brass
- Radiator flush for rust, as it removes rust and scale
- Used to remove light corrosion
Next up is the Design Engineering radiator coolant that is designed to help your cooling system distribute heat evenly. This coolant is added to maintain the operating temperature at 30 degrees, so that engine wear is reduced during regular use.
This coolant is used to tackle rust and corrosion and ensures the two are kept at bay. It is also ideal to tackle mineral deposits and keep them from affecting the health of the car. This coolant is added to maintain a pH level, which is extremely important for cars, as otherwise it can lead to damages.
It is ideal for small and big cars as well as regular and high mileage cars. The coolant is simple to use and there is no mixing needed. Simply, add it to the cooler and it will bring the temperature down to 30 degrees. Anybody can do it without a hassle.
- Special formula prevents corrosion and reduces rust and scale
- Ideal for water cooled engines
- Can be used with anti-freeze mixes
- Biodegradable and does not contain toxins
- Can safely be used with alloys and is non-corrosive
The gunk motor medic radiator flush is ideal for those who like to flush out radiators regularly. It is mild yet effective. This flush is perfect to ensure rust and scale does not build up. It is compatible with most engines and does a good job of eliminating contaminants.
This flush is made from high-quality detergents and salts that slide away build-up easily. It is safe to use and does not contain any harmful chemicals that can damage engine parts. This flush has good ratings and is popular among professionals.
It will flush out debris and pollutants within 5 to 10 minutes and effectively remove by-products of combustion. Although it is a little expensive, it is great for those looking for an effective flush that takes good care of their car.
- Reliable and gets the job done
- One of the oldest and trusted brands in the market
- Easy to use and should be used regularly to flush out engines
- Great for people looking for a quick fix
- Does not affect non-metallic parts of the radiators, engines and tubes
- Will keep seals and gaskets in good shape
If you have a radiator with lots of rust and scale build-up, then the Bar’s Leaks flush can help flush it out. The flush works on fixing the cooling system and ensures it is well maintained for a long time. It takes just 10 minutes for this flush to completely flush out all the pollutants and restore your car’s health.
This flush is easy and safe to use and should be used regularly to keep your car in top shape. It does not contain acids and will not require neutralizing. It is ideal to use with a number of high mileage engines. This flush is compatible with a range of cooling systems as well as aluminum and plastic radiators.
It is economically priced making it a great option for those on a budget. This flush delivers on its promise and makes sure your radiator is completely flushed out and restored within a matter of minutes. It should be used regularly to maintain engine and radiator health.
Add this product to your list of car maintenance inventory, and keep your engine running smoothly or years!
- Cleans the engine, radiator and cooling system
- Gets rid of oil and other pollutants
- Easy to use and works fast
- Safe to use and doesn’t contain acids and harsh chemicals
The last of our picks is the Permatex heavy duty radiator cleaner, which has great reviews to its credit. This engine cleaner is used by professionals to clean out oil and residue from engines. This tells you how good it is and must be used regularly to flush out contaminants.
Although this flush is a heavy-duty cleaner, it is quite gentle on your car and will not be too abrasive. This flush can be used to remove rust and build up from engines and radiators. It is ideal to clean out boiler tubes, coils and water jackets, making it a versatile flush to clean your car.
It easily dissolves rust, loosens gum and dirt and eliminates deposits. This flush offers complete care and protection so that your engine can run longer without any issues. Keep in mind that it cannot be used with aluminum parts.
- Easily removes rust and scales from radiators, boiler tubes and engines
- Can melt gunk and build up oils
- Quite effective and used in garages by professionals
Prestone AS105-6PK is a 2-in-1 formula designed for light flushing and heavy-duty cleaning of your cooling system, helping prevent overheat which is one of the top causes of engine failure.
It’s also formulated to remove any scale and heavy-duty rust deposits that might have grown on your cooling system due to neglect. With these deposits gone, coolant flow will become unobstructed and smoother and heat transfer will get better, so you’ll be saying goodbye to overheating, breakdowns, and costly repairs.
Note that this formula is 100% free of toxins and acid, making it SAFE for all the metallic parts of your cooling system. You can rest assured that it won’t cause corrosion or any form of damage to your cooling systems. Also, the absence of toxins and acid makes the product safer to use and easier to handle.
- 2-in-1 radiator flush formula
- Compatible with all cooling system metals
- Super-chelating additive removes heavy deposits
- Great for cleaning neglected coolant systems not only cleans but also removes grime and substantial rust
This particular radiator flush is a proudly made by Liquid Moly, a highly respected motor oil brand in Germany. Like any other high-quality radiator flush featured on this list, this product helps you clean and protect your vehicle’s entire cooling system.
The formula is fully compatible with metals, plastics, rubbers and antifreezes, which increases its versatility in terms of the types of radiators it can work with. With just a single flush of this radiator cleaning solution, you’ll be able to dissolve all the contaminants containing oil and lime…and even neutralize any harmful acids inside your cooling system.
This formula is known for its unparalleled performance when it comes to dispersing the icky sludge that tends to cause higher heat levels in your car. Its complete formula features no aggressive alkalis or acids, making it compatible with pretty much all types of antifreeze. Using this cleaner on your cooling system is easy as pie.
- High-quality, research-based product
- Hacilitates optimal engine temperature
- Compatible with rubbers and plastics
- Free of aggressive alkalis and acids
- Dissolves oil, grease, and sludge in your engine
- Compatible with all types of antifreezes
The first best radiator cleaner to try out is the Niteo motor Medic MF3. If you have a turbocharged engine then this is the best option for you. The formula is meant for diesel, turbo, and gas engines.
Although most engine flushes are safe to use with turbocharged engines, they will not do a great job of flushing out contaminants. Thus, going for one that is specifically designed for such engines can help you clean them out better.
This flush comes in a 32-ounce bottle size and can be used two times to flush out dirt, debris and oil build-up. If you think your engine is too clogged up then consider using the entire bottle at once.
Your engine will be as good as new in less than five minutes. This oil can increase engine longevity and be the perfect solution for old and rusty engines. It is best to use this flush just before an oil change. Keep in mind that the flush should only be poured when the engine is cool. It will work best with a cool engine.
- Flushes out sludge caused by slow driving
- Removes varnishes, gums, and oils
- Frees valves and pistons, and helps oils move freely
Best Radiator Cleaner Buying Guide
Choosing the right radiator cleaner is no rocket science. Following some easy to remember facts, you can differentiate between the bad and good. So, here are a few things to bear in mind.
Motor Flush Vs. Synthetic Motor Flush
Before buying a radiator flush, you must understand the difference between a synthetic motor flush and a regular motor flush. The former consists of extreme anti-wear additives that lend extra lubrication, while the engine is being cleaned out.
They are designed to flush out pollutants faster. These should be used with premium and diesel engines. Regular motor flush will not contain these chemicals and is recommended to use with regular engines.
Make sure to check if the flush will suit your engine. Although most oils are suitable for regular radiators, some should only be used with specific engines. Do not let the flush sit in the engine for more than five minutes as it can lead to damage.
Drain it out along with the oil and replace with new oil. Remember that motor flush should only go into the radiator and not any other system, as the chemicals can damage the parts. Follow label instructions.
How much flush you need will depend on the size of your car’s engine. For regular engines, six to seven quarts of oil can be flushed out using a bottle of radiator flush.
If you have a bigger car or an engine with a higher capacity then you might have to order a bigger bottle of flush. If you add in too little, then it might not completely flush out the system. So, make sure to add in the right quantity.
Lastly, choose a motor flush based on your budget. High end ones will do a better job at flushing out the engine compared to lower priced flushes.
Frequently Asked Questions
There’s not many queries you will find about radiator flush. However, we have answered a few FAQs for your reference.
1. What do motor flushes contain?
Motor flushes contain a mix of solvents and detergents dissolved in a petroleum-based carrier used to clean out the engine and radiator.
2. I use synthetic oils with cleansing properties, do I need a flush?
Yes. Although synthetic oils do a fairly good job of flushing out radiators, they do not break down some extreme debris that require heavy duty chemicals such as the ones contained in a radiator flush. Despite regular oil changes, a motor flush can do a better job at cleaning out the radiator.
3. Can the flush stay in my radiator?
No. The flush should be flushed out before driving. The motor flush is designed to drain out old oil from the radiator. It should only be used before an oil change and fully drained out before fresh oil is added in.
4. Can it be left in for 10 minutes?
No! That can damage your engine! Motor flushes should not be left in the radiator for more than 5 minutes unless the label instruction mentions otherwise.
5. Can I use it with a diesel engine car?
Yes. Most motor flushes are ideal for both gas and diesel engines. You can also look for flushes that are specifically designed for diesel engines, as they will contain special anti-wear additives designed specifically for diesel engines.
Radiators need to be flushed regularly to keep them in top shape. We have done our duty and given you our top 10 best radiator flush reviews. Now, it is up to you to choose the best one and order right away!