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Dirt and deposits in the cooling system can have fatal consequences. The fact that ‘only’ the coolant pump stops working is probably the least of the problems. It is much more unpleasant when more and more loose particles ‘vagabond’ through the cooling system and cause temporary blockages that are difficult to localize, which can lead to localized or even large-scale overheating, which in turn can cause expensive and ‘downtime-intensive’ consequential damage.

This is because modern cooling systems, due to the downsizing of commercial vehicles and the increasing use of lightweight
modern cooling systems have hardly any reserves left to cushion extreme thermal situations.

Radiator Flushes and Cleaner Best Choice

Best choice

Royal Purple Ice Super-Coolant Radiator Additive

It reduces engine heat by reducing the surface tension of the radiator fluids for improved heat transfer. Purple Ice fosters optimum coolant flow by helping to prevent formation of scale deposits in the radiator. It also lubricates the water pump seals.

5,0 Rating
optimizes protection
prevents erosion and electrolysis
compatible with all coolants types
up to 22°f reduction of coolant temperature
superior corrosion protection

How to Choose Radiator Flushes & Cleaner?

Radiator Flushes & Cleaners

Best 5 Radiator Flushes and Cleaner


Royal Purple Ice Super-Coolant Radiator Additive

  • provides year-round defense against corrosion
  • help to reduce engine temperatures

4,9 Rating

Check Best Price


Prestone Radiator Flush and Cleaner

  • 2-in-1 formula designed for light flushing and heavy-duty cleaning
  • removes heavy deposits by drawing metal oxides into the solution

4,9 Rating

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Hy-Per Lube Cool Radiator Cleaner & Super Flush

  • neutralizes acids that cause corrosion
  • helps to prevent formation of scales/deposits

4,8 Rating

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Permatex Heavy Duty Radiator Cleaner

  • removes rust and scale
  • cleans and unclogs stream cleaner coils and broiler tubes

4,5 Rating

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Liqui Moly Radiator Cleaner

  • removes deposits containing oil and lime
  • does not contain aggressive acids or alkalis

4,5 Rating

Check Best Price

We have tested the radiator flushes and cleaner and selected the best products for you.

How to choose a radiator cleaner?

Cleaning and flushing the system, which is responsible for cooling the heart of the car – the engine, is an extremely important procedure. The operating condition of the car directly depends on the condition of the radiator. If you allow excessive contamination, the consequences may be very deplorable: the radiator may be contaminated to the extent that there will be no fresh air flow to the engine, that is, it will simply overheat.

Choosing a radiator cleaner

Using a radiator cleaner

Due to too much rust, grease, and oil deposits, products of antifreeze decomposition, scale, which is formed during the washing of the system with non-distilled water, the radiator performance will be greatly reduced, and this will have an extremely negative effect on the condition of the engine.

Choosing a radiator cleaner

The car radiator is designed so that, being in front of the engine, it supplies cooled air to the working unit. In doing so, the radiator picks up all the dirt, dust, sand, and insects that move toward the car. This is called external contamination. There is also such a thing as internal contamination. The radiator cells are filled with scale, rust, products of decomposition of the coolant, engine oil. If you clean the radiator well, all these contaminants will be successfully removed. Now let’s talk more specifically about what radiator cleaners there are.

Radiator Cleaner

In order to clean the radiator, car owners use ordinary water, water with acid, as well as auto chemicals. Water is the least suitable for removing dirt and other compounds from the radiator. But due to limited choices, many people use water. Distilled water is ideal, but boiled water will do. However, due to the fact that the water is run through the system several times, a scale can form inside, and the method of cleaning itself is not particularly effective. Even boiling water will not remove most of the compounds. Acid water is used when the water you’ve distilled through the system has left scale in it. This indicates that the entire system is not working properly.

The best way to do your job is to use auto chemicals made specifically for this purpose. The cleaners include all kinds of compounds that can remove deposits of different nature. All car radiator contaminants can be divided into two types:

  • Scale – to remove it, you will need an acid;
  • Grease, organics – only alkali will remove them.

But you should remember a couple of nuances. For example, acid and alkali are incompatible with each other, because they neutralize each other, that is, you can not mix them. Also, these compounds can negatively affect the elements of the system.

Based on this, all cleaners can be divided into 4 categories:

  1. Acidic.
  2. Alkaline.
  3. Two-component cleaners.
  4. Neutral.


Means on the basis of one component, that is, acidic and alkaline, are not particularly popular, and in pure form they are extremely difficult to find. There are several reasons for this: the effect of such compounds on the entire system is extremely negative – the hoses, rubber pipes, plastic products will simply melt. That is, after using alkali or acid in the system, you will need to neutralize. Two-component cleaners are popular. The components of such cleaners are two solutions – an acidic and an alkaline one, which must be poured into the system one after the other.

A neutral cleaner does not have any aggressive compounds in its composition. The input components can be different, which will determine what the product can be applied to. Some cleaners can only be used for prevention, while others are able to dissolve even significant deposits.

In the composition of such a solution can be found:

  • The base of the cleanerю
  • Dispersants (preventing particles that have already “come off” the surface to be cleaned from sticking back).
  • Сorrosion inhibitors;
  • Protective agents (needed to protect system components from acid and alkali attack).
  • Solutions that are not harmful to plastic and rubber elements.

Radiator cleaner application


Special radiator cleaners are good in that they do not damage the internal elements of the system. Otherwise, every gasket would have to be replaced, and that would cost a lot of money. Any cleaner contains substances that can dissolve deposits of different nature. This greatly reduces the amount of time you have to spend cleaning the engine cooling system.

How often to flush

It is important to do regular flushing of the cooling system of the car. The fact is that depending on the coolant used, rust, oil deposits, antifreeze decomposition products, and scale accumulate on the walls of the tubes that make up the radiator, and this always has a bad effect on the engine performance and increases the wear of its individual parts with the risk of their premature failure.

It is worth noting that flushing the system can be both internal and external (external cleaning implies washing the radiator from the outside from particles of dirt, dust, insects on its surface). It is recommended to do internal flushing of the cooling system at least once a year. It is best to do it in spring when there is no more frost and hot summer is ahead.

On some cars there is a radiator lamp on the dashboard, the light of which may tell not only about low antifreeze, but also about the fact that it is time to change it. It can also be a signal that it is time to clean the cooling system. There are also a number of indirect signs of the necessity of such cleaning:

  • the radiator indicator on the dashboard
  • a radiator icon that signals a malfunction in the cooling system
  • frequent engine overheating;
  • problems in operation of the pump;
  • slow response to rheostat signals (inertia);
  • high temperature readings from corresponding sensor;
  • problems in “heater” operation;
  • fan is always running at high rpm.
David Muench (Carnes Mechanical)

David Muench (Carnes Mechanical)

Hey, I’m David. I’ve worked in a cars store for 6 years. I write reviews and guides, helping people to choose the most suitable technicals and best product for them. I’m happy to finally share my knowledge of the industry here, on CarnesMechanical.

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