What's the Best Radiator Flush?


Dec 07th, 2021

What's the Best Radiator Flush?

Every component in your car requires a unique maintenance task that you can order at your local workshop. When it comes to your radiator, that task is called a radiator flush, and there are several approaches to get it done.

A radiator flush is a method of thoroughly cleaning the inside of your radiator of any dirt, rust, and impurities by using a liquid flush, powder flush, or pressure-based flush. This allows the coolant to flow more freely and without restrictions and blockages that cause the engine to overheat.

Keep reading as we explore what a radiator flush is, why it matters, and the best methods for doing it.

What Is Involved in a Radiator Flush?

So, let’s begin by exploring what a radiator flush is all about. Firstly, the radiator is the central part of your engine’s cooling system. It measures your engine temperature and circulates coolant to prevent the engine from overheating. That coolant absorbs heat from the engine, then flows throughout the radiator. 

You’ll find the radiator towards the front of the engine bay, where there’s the most airflow. As the car moves forward, air will flow through the radiator’s fins and carry away all that heat from the coolant.

A radiator flush is precisely as the name suggests. The process involves draining the coolant already inside, then using another liquid to flush the entire radiator clean. In doing so, the process flushes out any build-up of dirt, rust, scale deposits, and anything else that reduces the radiator’s efficiency.

What’s the Difference Between a Coolant Flush and a Radiator Flush?

Now, don’t worry about these two different terms. Coolant flush and radiator flush are the same thing. Like many other things in the automotive world, different people and places will use one term over the other.

Regardless of what anyone calls it, the process is the same: flushing your radiator to clean it out from the inside and get it back to maximum efficiency.

Is a Radiator Flush Necessary?

Yes, a radiator flush is necessary at some point.

As you can imagine, the radiator will only do its job effectively as long as there’s nothing that prevents the coolant from flowing. Unfortunately, even though the system is sealed with a cap, things can still get into the radiator and lead to a partial or total blockage.

What can cause such a problem? Well, impurities like dirt, leaves, bugs, or anything else that shouldn’t be in the coolant can get trapped inside and stop the liquid from flowing. Typically, those impurities find their way into the radiator as you open the cap when pouring in the coolant.

How Do You Know Your Radiator Needs Flushing?

Now we know what radiator flushing is and why it matters. So how do you know when to do it?

Well, for starters, radiator flushing should be done as part of your vehicle’s scheduled maintenance. Your car user manual will have recommendations from the manufacturer on the frequency of doing it for your car.

As a rule of thumb, you should get a coolant flush done every two years or after every 30,000 kilometres, whichever one comes first.

A radiator flush also becomes necessary when there’s a problem with your car’s cooling system. Get a flush done if you notice these symptoms:

  • Car Overheats - This is the first and most obvious sign you need a coolant flush. If your car is overheating even if you have enough coolant and none is leaking out, that means something’s clogging up that radiator.
  • Noises (Grinding or Knocking) - Weird noises happen when the radiator is blocked, and coolant flows backwards into the heater. 
  • Coolant Leak - Tip: Yellowish, sweet-smelling stains under your car are likely signs of leaking coolant.

What Types of Radiator Flush Products Are There?

Now that we know the why's and how's of radiator flushing, let's talk about the best types of radiator flush products you can use. This section will help you compare liquid, powder, and pressure-based radiator flushes.

Liquid Radiator Flush

When you first heard or saw the term ‘radiator flush’, you likely imagined flushing that part out with a liquid. Well, that’s just one type of radiator flush that you can choose from.

This type of flush is the most common and straightforward approach. That means it requires very little specialised skill to do, and it's easy enough for you to do yourself at home.

A liquid radiator flush comes in either concentrated form or ready-to-pour versions. They're made primarily of sodium citrate and mild corrosives and catalysts. Together, these ingredients remove rust, residue, and other impurities from your radiator.

Powder Flushing Solutions

Powder flushing solutions are less common than the liquid ones described above. Still, they’re known for being much more powerful when it comes to getting rid of the grease and rust inside your radiator.

Better yet, since you’re free to decide how much powder to use, you can control precisely how strong you want the flushing solution to be. But, of course, there’s a little bit of know-how and careful handling necessary here, so this isn’t for the average car owner to do by themselves. That’s especially true, considering these powders will hurt your skin if you get any on you.

As a small side bonus, powder solutions also have a longer shelf life than liquid solutions. So, you can buy these and keep them away on a shelf for a much longer time.

Pressure-Based Flushing

Last but not least, we have pressure-based radiator flushing. This approach consists of using pressurised air and water to force debris and other impurities out of your radiator. In simpler terms, you're using brute force to clear your radiator instead of chemicals.

Since there are no harsh chemicals involved, you can flush your radiator this way more often without damaging it on the inside.

As you might imagine, this approach requires equipment to shoot that pressurised air and water through the radiator. So, perhaps this is less suited for home DIY radiator flushing.

Bottom Line: What’s the Best Radiator Flush to Use?

So, what’s the best radiator flush to use? Well, we’re going to say “it depends”:

  • Best For Being Gentle & Chemical-Free: Pressure-Based Flushing – Understandably, some car owners prefer treating their vehicles and their radiators gently by avoiding chemical solutions wherever possible. If that sounds like you, then you’ll appreciate pressure-based flushing. It gets the job done without using harsh corrosives.
  • Best For Custom Use: Powder Flushing Solution – Some people want to have more control over how intensely they flush their radiators. So, if you prefer the flexibility to tweak the flushing solution as you please, then a powder-based product is ideal.
  • Best For General Use: Liquid Radiator Flush – Drivers who just want a straightforward solution to their radiator problems are best served by a conventional, no-fuss liquid radiator flush. That's especially true since these products are available at pretty much all workshops around.

Looking for a place to get a radiator flush done? Check out the Directory at CarPart AU. Use the drop-down menu to narrow down automotive workshops in your area and find their contact details!

By Ray Hasbollah