4 Key Points About Freeze Plugs

You probably already know that a coolant leak in your car can cause rapid overheating, potentially doing catastrophic damage to the engine. However, you might not realize that the cause of your coolant leak and engine overheating may stem from small, cylindrical plugs in your engine block known as freeze plugs or core plugs.

Since freeze plugs typically last for the life of an engine, you might never hear about the need to repair or replace them. You might not even understand what these inconspicuous little items do for your vehicle or how you can keep them in good working order. The following four key points should enlighten you on the subject.

1. Why and How Your Car Uses Freeze Plugs

Freeze plugs stop up the holes left behind by the sand casting process for manufacturing engine blocks. These plugs play an important role in protecting the finished engine block against cold-weather damage by popping out if ice inside the engine presses against the block's walls, releasing the pressure before the block can crack.

Freeze plugs proved especially critical in the days when drivers used plain water as their coolant during the warmer months of the year, then forgot to swap out that plain water for a water and antifreeze mix once temperatures cooled. Even today, they protect engines against coolant leakage and compromised, ineffective antifreeze mixtures.

2. What Can Go Wrong With Freeze Plugs

As noted above, freeze plugs can pop out in response to the pressures of expanding ice in an engine's coolant. Even if your freeze plugs never actually pop out, however, they can still go bad for a variety of reasons. For instance, the galvanized steel that makes up the freeze plugs can rust over time, promoting leaks.

Leaky freeze plugs can lead to serious problems. Even a slow, pinhole-size leak will allow your coolant levels to drop, making your vehicle chronically vulnerable to overheating that can destroy the engine. The escaped water or coolant will also run down the engine, potentially causing trouble for other parts of the block.

3. When to Suspect a Freeze Plug Problem

A failed freeze plug can produce some telltale symptoms that should alert you to the need to check your engine. For instance, you may smell burning coolant or see white smoke pouring from your exhaust pipe. You may also encounter performance problems when idling or accelerating, including engine misfires.

Not all freeze plug problems call attention to themselves through such dramatic symptoms. Your first inkling of a bad freeze plug may come when you see a milky discoloration in your engine oil or when your car seems to overheat more quickly and easily than usual.

4. How to Cope With (and Prevent) Freeze Plug Failure

Resist the temptation to fill a freeze plug leak with an over-the-counter leak stopper product. This measure will only work temporarily and only for the smallest leaks. Skilled automotive technicians know how to provide more effective and lasting solutions by replacing the failed freeze plug with a fresh new one.

In many cars, the freeze plugs occupy easy-to-reach areas of the engine block, making their replacement a relatively quick and simple matter. If your engine's freeze plugs don't lend themselves to easy access, your mechanic may need to remove the entire engine to perform the replacement.

The easiest way to avoid freeze plug problems involves staying on top of your engine coolant status. Schedule regular preventative maintenance inspections so your automotive technicians can catch low coolant levels, old antifreeze that needs replacing, and obvious freeze plug corrosion or leaks.

When your car suffers from coolant system trouble such as a freeze plug failure, rely on Kell Radiator Service for the solution. Our skilled technicians can check the system's various components, repair or replace faulty parts, and refill your coolant so you can drive your car with confidence again. Contact us to request an estimate.