The piston is one of the main components of the engine, and due to its constant operation under high temperature and pressure conditions, it is often prone to phenomena such as cylinder pulling, fracture, damage, and even cylinder ramming. Apart from the piston itself, any other component related to it that malfunctions may cause damage to the piston and result in engine failure. Here is an analysis of common piston faults.

1、 Reasons for piston related cylinder ramming

The so-called cylinder ramming refers to the phenomenon of severe damage to important components such as engine cylinder liners caused by the impact of a damaged internal part of the engine on the engine body. Cylinder ramming is one of the biggest faults of engines, which has great destructive power. The piston strength is relatively low. In addition to the unqualified chemical composition or metallographic structure of the piston, poor quality pistons cannot withstand the working environment of high temperature, high pressure and high load, causing cylinder ramming accidents. Other reasons include:

1. Due to the valve falling into the cylinder, the top surface of the piston is damaged, and in severe cases, the piston may break, causing a cylinder ramming accident;

2. After the piston pin broke, the broken piston pin generated torque on the piston pin hole during its continued movement, causing the piston pin to break and the connecting rod to detach without further movement, resulting in the piston being crushed and causing a cylinder ramming accident;

3. Due to the damage of the cylinder liner, the piston broke due to resistance during movement, causing cylinder ramming;

4. Due to a malfunction in the lubrication system, the phenomenon of shaft holding occurred, causing the piston to exceed the normal load range during operation and resulting in cylinder ramming;

5. The crankshaft and connecting rod break and collide with the piston and cylinder liner, causing cylinder ramming;

6. The detachment of connecting rod screws can also cause piston damage and result in cylinder ramming;

7. After the engine severely pulls the cylinder, the piston and cylinder liner lock up, and the piston is twisted and broken by external force without being able to reciprocate up and down;

2、 Reasons for piston pulling cylinder

Piston pulling cylinder is a common fault, and in mild cases, it is caused by dry friction that causes the surface of the piston to become rough; When a slight knocking sound is heard from the engine, metal deposits have formed on the surface of the piston. If not repaired in time, the piston and cylinder liner may lock up. The reasons are as follows:

1. The lubricating oil is too thin to provide effective lubrication or the lubrication system (such as the oil pump) malfunctions, causing an increase in the friction coefficient between the piston and cylinder liner, resulting in cylinder pulling;

2. Improper adjustment of engine ignition time can cause engine detonation and explosion, and high engine temperature can damage the oil protection film, leading to cylinder pulling;

3. Failure to replace and clean the engine air filter, lubricating oil filter, and fuel filter in a timely manner has polluted the working environment of the cylinder, leading to cylinder pulling;

4. Overloading of the engine and problems with the cooling system have damaged the oil film, leading to cylinder pulling;

5. Excessive carbon buildup in the engine causes the detached carbon to enter the cylinder block, leading to cylinder misfire;

6. The piston ring is stuck or broken, leading to cylinder pulling;

7. The bending of the connecting rod changed the direction of piston movement, causing cylinder pulling;

8. Improper installation of the piston or mismatch between the installed piston and cylinder liner, as well as excessive or insufficient clearance, can also cause cylinder pulling.