Quickly Distinguish between Cylinder Gasket And Cylinder Body Cracking

Both the cylinder gasket and the cylinder block cracking can cause engine coolant leakage, power drop, abnormal water temperature and other faults, and the symptoms of the two faults are highly similar, but the repair methods and costs are vastly different. The cylinder gasket is a vulnerable component with low repair difficulty; The cracking of the cylinder block belongs to the damage of the engine body, and the repair cost is high, even requiring the replacement of the cylinder block. Therefore, quickly and accurately distinguishing between the two is the key to subsequent repairs.

1、 Preliminary distinction of intuitive representation

From the development of the fault and external traces, a quick preliminary judgment can be made. The failure of the cylinder gasket is mostly gradual, with only slight idle shaking and a slight decrease in coolant in the initial stage. As the fault worsens, there is a sudden increase in water temperature and oil emulsification; The leakage traces are mostly concentrated on the joint surface between the cylinder head and the cylinder block, appearing in a linear or point shape, and will reappear shortly after wiping.

The cracking failure of the cylinder block is mostly sudden, often caused by high temperature, impact or cold shock of the engine. When the fault occurs, it is directly manifested as a sudden increase in water temperature, a large amount of coolant leakage, and even accompanied by abnormal engine noise; The leakage marks have no fixed location and can appear on the side walls of the cylinder body, water channel interfaces, and other parts. Some cracks may also be accompanied by metal scratches or damage, and the leakage marks will quickly spread after being erased.

2、 Accurate determination of core detection

1. Oil and coolant status detection

The most typical feature of the cylinder washer is oil emulsification, coolant enters the oil pan, milky white foam like mixture will appear on the oil dipstick, and oil may float in the coolant pot; If the cylinder block cracks without penetrating the oil passage, only coolant leakage will occur, and the oil condition is basically normal. If it penetrates the oil passage, although the oil will also emulsify, the emulsification speed is much faster than that of flushing the cylinder gasket, and the oil will completely deteriorate in a short period of time.

2. Cylinder pressure and airtightness testing

By using a cylinder pressure gauge to detect the pressure of each cylinder, the flushing gasket often shows that the pressure of adjacent cylinders is too low at the same time, and the two cylinders are interconnected due to damaged cylinder gaskets; Cracks in the cylinder body are often caused by a significant decrease or even zero pressure in a single cylinder, which can directly lead to the failure of the cylinder seal. In addition, when pressurizing the coolant system, the cylinder head gasket only leaks air at the joint surface of the cylinder head. If the cylinder block cracks, bubbles will appear at the crack location of the cylinder block, and the leakage location is independent of the joint surface.

3、 Auxiliary feature supplementary identification

The malfunction of the cylinder gasket will be accompanied by white smoke from the exhaust pipe. As the coolant enters the cylinder to participate in combustion, the white smoke is light and continuous, and the higher the water temperature, the more obvious the white smoke becomes; If the crack in the cylinder body leads to the cylinder, the white smoke in the exhaust pipe will be more intense, even mixed with water droplets. If it is only a water channel crack, there will be no white smoke emission, only rapid loss of coolant.

In addition, before the occurrence of cylinder gasket failure, there are often early signs such as long-term high temperature of the engine and loose cylinder head bolts; Cracking of the cylinder block is often caused by sudden high temperature and sudden cooling, external impact on the engine, and metal fatigue of old vehicle models. Combined with the usage of the vehicle, it can be further distinguished.