Engine cylinder head gasket burning and compression system air leakage are frequent failures. Cylinder head gasket burns will seriously deteriorate the working condition of the engine, or even fail to work, and may cause damage to certain related parts or parts; in the compression and power stroke of the engine, the sealing of the upper space of the piston must be intact , No air leakage.
1. Failure performance after the cylinder head gasket is broken
Due to the different locations of the cylinder head gasket burnt, the signs of failure are also different:
blow-by between two adjacent cylinders
Under the premise of not turning on the decompression, I shook the crankshaft and felt that the pressure in both cylinders was not enough. When the engine was started, black smoke appeared, and the engine speed decreased significantly, showing insufficient power.
2. Cylinder head leaks
The compressed high-pressure gas flees into the cylinder head bolt hole or leaks from the joint surface of the cylinder head and the body. There is a light yellow foam in the air leak. When the air leak is serious, it will make a sound of “adjacent”, sometimes accompanied by water or oil leakage. You can see the corresponding cylinder head plane and its vicinity during disassembly and inspection. There is obvious carbon deposit at the bolt hole of the cylinder head.
3, in the gas oil passage
High-pressure gas rushes into the lubricating oil passage between the engine block and the cylinder head. The oil temperature in the oil pan is always high when the engine is running, the viscosity of the oil becomes thinner, the pressure decreases, and the deterioration is rapid. There are obvious bubbles in the oil sent to the upper part of the cylinder head to lubricate the air distribution mechanism.
4, high-pressure gas enters the cooling water jacket
When the engine cooling water temperature is lower than 50℃, open the water tank cover, you can see that there are obvious bubbles rising and emerging in the water tank, and a lot of hot air is emitted from the water tank mouth. As the engine temperature gradually increases, The heat emitted from the water tank mouth has also gradually increased. In this case, if the overflow pipe of the water tank is blocked and the water tank is filled with water to the lid, the phenomenon of bubbles rising will be more obvious, and the phenomenon of boiling will appear in severe cases.
5, the engine cylinder and the cooling water jacket or the lubricating oil passage pass through
There will be yellow-black oil bubbles floating on the upper surface of the cooling water in the water tank or there will be obvious water in the oil in the oil pan. When these two blow-by phenomena are serious, water or oil will be in the exhaust.