Here's How You'll Know If Your Radiator Needs To Be Flushed

A car's cooling system is like a linebacker — it's the most important component in a car engine's defense system. It ensures the engine runs at optimal temperatures and prevents it from overheating. Yet the cooling system is one of the most neglected systems when it comes to car maintenance, often dealt with a fill it, shut it, forget it attitude. Ignoring your cooling assembly and avoiding a simple preventive maintenance step such as a coolant flush can lead to a cascading series of catastrophic failures. 

However, there are a few indicators that'll tell you it's time to flush your radiator. Like if your car overheats despite the coolant level in your car being full. Or if you hear a grinding or knocking noise from your engine or smell something sweet under your car's hood. (Electrolysis is another silent coolant system killer, and a good reason to check your coolant from time to time.) 

Let's first understand how your car's cooling system works. It's obvious that a cooling system keeps the engine cool, but it also needs to ensure the engine is running at an optimal temperature range for best performance, efficiency, and longevity. For most vehicles, this temperature range is between 195 and 220 degrees. In most cars' cooling systems, a liquid coolant, propelled by a water pump, flows through hoses inside the engine to the thermostat and radiator before moving back to the water pump. This takes heat away from the engine and disperses it into the air.

In older times water was used as a heat-transfer medium instead of coolant. In modern times, a mix of 50% water and 50% coolant (or antifreeze) is used. If you live in colder regions where temperatures regularly drop below the freezing point, a mix of 60% antifreeze and 40% water is preferred.

It is imperative to replace your coolant periodically as over time, coolant in a car system deteriorates. This can lead to the formation of rust, scaling, and debris inside the cooling system, affecting coolant flow or blocking it. This could cause the engine to overheat and suffer irreversible damage. Coolant also loses its antifreeze properties over time which, if you live in a region with harsh winters, can cause water in the coolant mix to freeze and expand, damaging engine components.

There are ways to identify if your engine needs a coolant flush. The most common one is the engine overheating even while driving on open roads, despite the coolant level showing full. This is due to debris blocking coolant flow and reducing cooling efficiency. Your engine bay smelling sweet is an indicator of overheating coolant. This is due to burning ethylene glycol present in coolant. Other identification factors are visible contamination in coolant, leaks, and knocking or grinding noise in the engine.

Generally, you should flush your car's radiator every two years or 30,000 miles, but this guideline can vary according to the car model. Check your owner's manual for the manufacturer's recommended schedule.  Replacing your coolant removes contaminants, and a fresh coolant will do a better job of keeping your engine cool. A coolant flush is like a deep cleaning of your car's cooling system. It ensures that the new coolant remains uncontaminated by debris in the coolant system and prevents debris buildup as well .

While you might call coolant flushing a DIY job, it is not recommended, as coolant is toxic to both people and animals, and should be disposed of properly. A coolant flush at a dealership will cost between $200 to $250, but might run as low as $40 at an independent mechanic. While there are worse things you can do to your car, ignoring coolant system maintenance is a definite no-no. Proper maintenance of the coolant system will ensure a cool engine and prevent potentially expensive engine failure.