2016 Ford Focus - Freeze Plug/Kit

What Are Engine Expansion Plugs?

An engine expansion plug, also known as an engine freeze plug, seals off openings in the engine block or cylinder head that are necessary during the manufacturing process, but are not intended to be permanent. During the manufacturing of the engine, these plugs are installed in various locations that were originally intended to facilitate the casting process. Engine freeze plugs are also designed to help prevent damage to the engine block caused by coolant freezing inside the engine. If the coolant-to-water ratio in your engine is incorrect, it is possible that water can freeze inside the engine block's water jackets during cold weather. When water freezes, it expands, which can crack or otherwise damage your engine block and require a costly repair. Freeze plugs are made to allow for this expansion, and often pop out of the engine block or cylinder head when water freezes inside the water channel. Expansion plugs can also suffer from corrosion that can lead to pinholes and allow coolant to leak. Engine expansion plug kits are available for engine repair or rebuilding purposes, and usually include multiple plugs of different sizes to accommodate various openings in the engine. When replacing an engine expansion plug, the old plug is typically removed by prying it out with a suitable tool. The new plug is then inserted into the hole and tapped into place using a rubber mallet or a specially designed installation tool. If you are repairing or rebuilding an engine, O'Reilly Auto Parts carries freeze plug sets with the correct sizes for many engine types to help you make a confident, lasting repair.