How to Remove a Frost Plug

Frost plugs, also called freeze plugs or expansion plugs, are supposed to protect the engine block if the coolant in the block freezes---which happens rarely among engines with the proper mixture of coolant and water. If the coolant freezes, the expanding liquid should push out the plug, providing additional expansion space for the freezing coolant and easing pressure on the block. Frost plugs are made of steel and will eventually rust out and leak.

Instructions

1

Locate the frost plug you want to remove. Depending on your particular engine and the location of the plug, you may have to raise the vehicle with a jack and support it with jack stands to approach it from underneath the vehicle. You may also have to remove a component that is in the way.

2

Place a punch against one edge of the frost plug and strike the punch with a hammer. You want to tap that edge of the plug into the engine block and pivot the opposite edge out of the block.

3

Grab the edge of the plug that is sticking out with a pair of pliers and work it out of the engine block.