It is easy to be misleading when trying to diagnose a bad/ blown head gasket. Symptoms will often vary considerably, depending on how the gasket fails. The term “blown head gasket” does NOT necessarily describe a single thing. Head gaskets may fail in several different ways. With each failure type, different symptoms may result. The symptoms each person sees depend on how and where the head gasket fails.
To make diagnosis even more confusing, other things may cause the same symptoms as a head gasket failure. Another issue may be multiple failures which can cause more than one symptom. For example, a restricted radiator may cause an engine to overheat, very much the same as a head gasket failure. The farther we drive the vehicle, the more it may overheat. Often, intake gaskets cause coolant in the oil. Coolant in the oil is often mistaken as a head gasket. Each of these symptoms may suggest a head gasket problem but may have another explanation. Diagnosing the problem requires experience and a logical approach.
Consequences of not replacing a bad head gasket
Because of the difficulty in diagnosing and the expense of repairing a head gasket, we may be tempted to let it go. This is a big mistake. Depending on the type of failure, far more damage will soon occur.
If coolant enters the exhaust, through the combustion chamber, the catalytic converter(s) is often damaged. Coolant in the engine oil may destroy the engine, by breaking down lubrication. Combustion gases that leaks into the coolant usually results in continued overheating and more damage. Hydrocarbons entering the coolant will also greatly increase corrosion. This may destroy the radiator, heater core and other expensive components.