The seal of the head is the seal between the motor block and the head. It is not subject to periodic maintenance, so it should only be replaced when it is needed.
In practice, the only time to replace it is to develop leaks that allow the engine coolant to penetrate internally or externally where it should be visible. Internal leaks allow the cooling liquid to be burnt in the combustion chambers.
A “head” head seal can cause a number of different symptoms: engine oil cooler, engine ignition or engine leakage, low level of coolant, a motor that runs at a higher temperature high above or overheat, and steam that appears as white smoke coming out of the exhaust gas.
It is easy to fall into error when trying to diagnose a “gone” head seal. Symptoms often vary greatly, depending on how the gasket abandons you. To make the diagnosis if possible even more confused, other things can cause the same symptoms as a “gone” head gasket.
For example, a narrow radiator may cause engine overheating, much like a head seal. The longer we drive the vehicle, the more it may overheat. Often, the suction gaskets make the coolant go into the oil, which is often mistaken as a problem with the head gaskets.
Each of these symptoms may suggest a problem with the head gasket, but may also have another explanation. Diagnosing the problem therefore requires experience and a logical approach. Because of the difficulty in diagnosing and repairing a head seal, we may be tempted to let go of it. This is a big mistake.
In fact, depending on the type of failure, there will be many more damages. If refrigerant enters the exhaust gas through the combustion chamber, the catalytic converter often becomes damaged. Coolant in engine oil could destroy the engine by cutting off the lubrication. Combustion gases that end up in the refrigerant usually result in constant overheating and more damage: for corrosion, in fact, you could easily destroy the radiator, heater core and other expensive components.