Freeze Plug Leak (Causes & Fix)

Do you have a freeze plug leak and want to know why and how to fix it? Look no further because we have got you covered.

This article provides you with the common reasons why your car is experiencing a freeze plug leak, how to get it fixed, how much it will cost to fix a freeze plug leak and how to save on a freeze plug replacement.

Let’s get into it!

When freeze plugs are installed in your car engine block, they are intended to slow down any freezing water that may accidentally mix with the engine’s lubrication oil.

Water in the cooling jacket can exert approximately 100,000 PSI on the engine blocks without adequate antifreeze protection. This pressure can easily crack aluminum and cast iron used to make the engine. An engine block that is cracked not only renders your car engine useless but is also very difficult to fix.

If you experience a freeze plug leak in your vehicle, it could mean that your vehicle’s cooling system froze or ran dangerously close to its freezing point.

If this happens, check your car’s engine for any damages and check the antifreeze to ensure the mixture is in check and that its freezing point is below 0 degrees Fahrenheit.

A freeze plug can also become loose over time, and you have a freeze plug leak due to the heating and cooling cycles that occur while driving your vehicle!

A water-cooled engine inside your car can present problems if your vehicle is operated in freezing weather. When water freezes, it expands as it changes from a liquid to a solid form.

There are many issues today caused by the expansion of water as it changes form, such as things on the road breaking due to frost heaves or pipes in houses getting burst due to water expanding when it freezes!

The same thing happens in your car’s cooling system as well, since it is filled with only pure water – so it is best to put more stop freeze into the water to lower the freezing point of the water.

Also Read: How to Remove O2 Sensor without Socket

Freeze Plug Leak Symptoms

Freeze Plug Leak Symptoms

If you are experiencing any of these symptoms below, it most likely means that your car has a freeze plug leak.

  1. Your engine has coolant leaking down the side.
  2. Water leaks from the engine to the transmission due to a hole in the bell housing.
  3. When you smell heated coolant, and there is coolant leaking from your engine, this might indicate that you have a freeze plug leak.
  4. An engine that constantly overheats might indicate that almost all of the coolant in the vehicle’s engine has probably leaked out. This might also indicate a freeze plug leak.

How to Fix a Freeze Plug Leak

A freeze plug leak is a type of leak that can either be fixed or stopped by using a stop leak. Because of the freeze plug location and the hassle, they require to install, Replacing it with a new metal freeze plug is mostly not an option.

Rubber expandable freeze plugs are available from a few manufacturers, but you shouldn’t use them because they usually end up protruding into the engine’s cooling jacket and could create a hotspot. Also, rubber freeze plugs typically do not hold up for too long, resulting in you having to deal with another freeze plug leak.

You can repair a freeze plug leak by following the steps below.

  1. To start, cover the entire freeze plug with a sealant. The sealant only prevents leakage while you wait for replacement parts because it is not meant to be a permanent fix.
  2. After getting the replacement parts, hit the freeze plug continuously until it pops out entirely, then pull it out using pliers.
  3. Use sandpaper to remove old sealants and rust from the inside of the hole. Additionally, you may see some signs of corrosion, so make sure you clean them out. If you don’t, you will almost certainly experience another freeze plug leak in the future.
  4. Install the new freeze plug. Once the plug is in place, use a screwdriver or pliers to drive it in. Use a sealant to surround the plug after this is done to secure it into position further.

Check out this video for tips on how to replace a leaking freeze plug

Also Read: How to Put a Car in Neutral Without a Key

Frequently Asked Questions About Freeze plug Leak

Do Freeze Plugs Leak Oil?

No, freeze plugs do not leak oil. Freeze plugs are used to keep in the coolant and not oil. What you are

How Do You Stop a Freeze Plug From Leaking?

A sealant can temporarily be used to stop a freeze plug or seal its cracks. However, a complete replacement is necessary if the freeze plug is damaged. The sealant only provides a temporary solution until you get the necessary replacement parts.

Can You Drive With a Leaking Freeze Plug?

You could drive with a freeze plug leak if you are left with no choice. In theory, if you can maintain the engine coolant level of your car and ensure that the car’s engine doesn’t get too hot, you might be able to drive with a freeze plug leak, though you shouldn’t do so. It gets messy, and the freeze plug leak might increase the chance of your car engine overheating.

Can a Bad Freeze Plug Cause Overheating?

Yes, a bad freeze plug can cause overheating. A freeze plug that is malfunctioning on the engine block could cause a leak in your car’s cooling system. Coolant Leaks can also develop due to a malfunctioning or loose engine gasket, thereby causing the engine to overheat.

How Long Does It Take to Change a Freeze Plug?

A total of about 6 hours of labor time is required to change freeze plugs in a vehicle, including any other parts or fluids needed. 4.5 hours is needed to remove and replace the transmission in the car. Then, an hour’s work is required to install the freeze plugs at the rear of the car, and another 1/2 hour to install each additional one.


A Freeze plug is a vital component in your car’s engine because it helps prevent your car’s coolant from leaking out of your car. If you ignore them, in time, they may cause the coolant level in your engine to drop so much that it is unable to cool your car’s engine effectively.

This can lead to overheating of the engine, and if not fixed quickly, it could potentially cause extensive damage. The minute you suspect your car might be experiencing a freeze plug leak, have it inspected immediately by a Certified Auto Repair specialist.

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