An engine's head gasket serves the purpose of sealing the automobile's engine cylinders against water or coolant from elsewhere in the engine. A blown head gasket can allow water or coolant to infiltrate an automobile's oil supply; this can, in turn, cause a whole host of expensive problems for your automobile. As such, it is important that you remedy a blown head gasket as quickly as possible. While it is important that you eventually seek a replacement head gasket, there are ways you can temporarily seal the gasket.
Read your automobile's user manual; note any instructions it may have regarding sealing broken head gaskets and keep these in mind throughout this process. Defer to the information in the user manual in all cases; what is listed here is a general, not product-specific, process.
Drain the antifreeze in the radiator. Check your auto's user manual for the location of your engine's radiator; most user manuals will also have a schematic of the radiator itself. Use this schematic to locate the valve at the bottom of the radiator (in lieu of this schematic, the location of the valve is still fairly evident). Place the drainage pan under the valve. Open the valve and allow the antifreeze to drain. Pour the antifreeze into a covered container. Close the drainage valve.
Read the instructions on the engine sealant bottle. Prepare it as instructed and in the quantity instructed. In the case of a disagreement between the instructions listed here and the instructions listed in the sealant bottle, adhere to the instructions of the brand specific sealant.
Locate the intake into your automobile's radiator. Open the radiator cap and pour in the engine sealant as directed by the instructions on the sealant bottle, in the quantity specified by the instructions. Close and seal the radiator cap.
Turn on your engine. Allow it to idle for 30 minutes or more. This will allow the engine sealant to spread to the rest of the radiator.
Allow a day's driving for the engine sealant to fully take effect.
Turn your engine off and place a radiator drainage pan under the radiator. Drain the radiator, using the instructions specified in Steps 2 and 3. Place the radiator fluid in a closed container.
Replace your automobile's antifreeze, using the antifreeze type and quantity specified in your automobile's user manual.
Seek instructions at your local auto parts store regarding the proper way to dispose of radiator fluid in your state.
