How to Properly Clean a Clogged Radiator


Just like any other car part, radiators are subject to the ‘ol wear and tear. Over time, debris, such as “black magnetite sludge” (caused by the rusting of components) may become lodged in the pipes, clogging it and causing symptoms such as overheating, interior heating, obvious coolant leaks below the car, and so on.

Before you take your car to the nearest auto repair shop and spend a lot of dough, take a look on ways you can properly clean that clogged radiator first.

Let the engine cool

In cleaning straight fin radiators, never ever attempt to clean a car before turning off the engine and letting it cool down first. To begin with, when a car’s engine is operational, the coolant circulates from the engine to the cooling system, passing through the tubes before going back to the engine again.

The circulation of the coolant will interfere with the cleaning process, deeming it a necessity for you to make sure that the engine is no longer hot when you start cleaning. Also, the pressure inside the engine compartment could force the coolant to spray out of the radiator cap when you attempt to clean it while still hot, so there’s that, too.

Put a bucket underneath the radiator

While letting the engine cool, place a small bucket at the bottom of the radiator. This serves as a catch basin for all the debris that will be flushed out.

Remove the cap and fill the tubes with radiator flush

Once the car has cooled down, take off the radiator cap. Take a bottle filled with radiator flush solution and pour out as much as you like. According to our friends at Cars Direct, radiator flush is beneficial to your car for a number of reasons:

1) Rust, black magnetite sludge, and other debris stuck inside the radiator pipes are removed, immediately solving the symptoms mentioned at the start of this article.

2) The flush lubricates the water pump, lengthening its life.

3) Radiator flush also takes out any remaining residue of the coolant within the tubes. This prevents any further buildup that leads to clogging or underperformance.

4) Aside from taking out debris caused by rust or buildup, flush solutions also protect the radiator’s interior from rust and clogging, making sure its performance remains optimal.

Let flush solution simmer in the radiator

Allow for about 5 to 10 minutes for the flush solution to work its way through the radiator piping system. This guarantees a thorough cleansing process inside so that.

Flush out the solution with water

…the next and final step is an easy and painless process. You can either use a hose connected to a water source or a dipper filled with water to rinse the radiator’s interior pipes. Then observe bucket you placed beneath it, which should be filling up with the debris and other contaminants that were causing the blockages in the first place.

The reason why Step #4 is necessary is because if the flushing is done hurriedly, not all the rubble inside the radiator will be cleaned, hence the need to start over.