The head gasket in your engine has one of the toughest jobs in the engine dealing with both very low and very high pressures and a wide range of temperatures, so it’s not surprising that they do end up failing from time to time. When someone says a car has a blown head gasket, they mean the head gasket has developed a leak. It can often be difficult to tell if you have a blown or leaky head gasket. We have seen many cars drive for many miles before they start showing symptoms.
As you drive with a blown or leaking head gasket, the cooling water and exhaust gases are entering places they were never designed to be and can cause severe temperature fluctuation across the mating surface of the block and the head. These fluctuations over time can cause the metal to wear or even warp significantly. If not fixed quickly the areas on the engine will warp and cause a poor seal even with an installation of a new head gasket. In order to fix a leaking head gasket the heads and block will most likely need to be machined flat again.