If your car's engine is overheating and you notice a blue-green fluid pooling underneath your car or in the engine bay, you most likely have a leak in your radiator. Coolant flows through the radiator in order to shed the heat it picked up while flowing through the engine, and this circulation is how it keeps your car's engine cool. Radiators often start leaking as they age when the aluminum corrodes. High-pressure coolant flowing through the radiator pushes through the weak, corroded area and causes a pinhole leak.

One method of plugging a pinhole leak is to put a stop leak additive in your coolant. However, this usually isn't the best choice for repair. Read on to learn more about how stop leak additives work and why they might not always be the best choice to fix a leaking radiator.

How Do Stop Leak Additives Work?

Stop leak additives are made of solids like aluminum or ceramic that are suspended in a solution. You add them to your car's coolant, and they'll circulate through the radiator along with the other parts of your car's cooling system like the water pump and heater core. Stop leak additives will harden quickly when they encounter air. As they circulate through the radiator, they'll harden as soon as they start to flow out the leak, which will plug it.

Should You Use a Stop Leak Product to Fix a Leaking Radiator?

While stop leak additives can be effective at plugging a leak, they carry some serious risks. The primary problem is that coolant is constantly flowing through the radiator at high speeds. The coolant may break off a chunk of the hardened stop leak product, which will continue flowing through your car's entire cooling system. This can happen repeatedly — the leak may reopen, causing more of the additive to harden and plug it, and then the hardened additive will break off and continue to circulate around in your coolant.

Unfortunately, this can lead to accumulated bits of hardened stop leak additive building up and forming a clog in your car's coolant system. Coolant will no longer be able to circulate, which means that your engine will quickly overheat — with no circulation, the coolant can't shed the heat it picks up from the engine. In addition, fixing this problem is much more expensive than replacing a leaking radiator, since an auto repair shop will need to carefully inspect all of your coolant tubes and pipes in order to find out where the clog is located. If the clog is in a component like the heater core (which is the source of heat for your car's heater), it will need to be replaced, which adds to the cost of repairs.

It's much better to have your radiator replaced at an auto repair service instead of using a stop leak additive to plug the leak in your radiator. While these products may be an inexpensive way to plug a pinhole leak, they carry unacceptable risks. Replacing your leaking radiator is a risk-free way to stop the leak and allow your engine to cool properly again.

To learn more about this, reach out to an auto repair shop.