Head gasket sealers can temporarily stop or slow down leaks due to a blown head gasket. In some cases, a gasket sealer can stop the leak indefinitely. The only sure way to permanently repair a leaking head gasket is to replace it.
The head gasket forms a seal between the engine block and the cylinder head. It acts to prevent coolant and oil from leaking into the cylinders. It is one of the more critical parts of an internal combustion engine.
If a head gasket blows, often the first sign is engine overheating due to loss of the leaking coolant. Coolant leaking into the cylinders can cause excessive wear and damage. If the coolant levels are dropping without any visible signs of leaking coolant, a blown head gasket may be the problem.