Gasoline engine will produce knocking phenomenon. Analyze the phenomenon of knocking. It is necessary to understand the cause and solve it according to the crux.
The combustible mixture of a gasoline engine is initially ignited by high pressure. Then, the burning flame takes the spark plug as the center and spreads outward, igniting all the mixed gas in the combustion chamber. This combustion process is normal combustion. If the remaining mixture ignites without being ignited before the flame arrives, this kind of combustion is called knocking.
Knock is not allowed to occur in the normal operation of the engine. It will cause increased abrasion, shortened service life, and even rapid destruction of various parts of the engine cylinder block. It will also reduce engine power and increase fuel consumption.
The phenomenon of knocking:
1. Knock will suddenly produce shock waves in the cylinder and impact on all sides, causing strong vibration of the engine’s pistons, cylinder walls, connecting rods, crankshafts, etc., and irregular metal percussive sounds;
2. The temperature of the cooling system is too high;
3. Incomplete fuel combustion and black smoke in the exhaust gas;
4. The engine power drops and fuel consumption increases.
Solution:
1. Reduce the ignition advance angle;
2. Use gasoline with a brand (octane number) that meets the regulations;
3. Remove carbon deposits in the combustion chamber;
4. If knocking occurs when the car is going uphill, switch to a low gear in time;
5. When the car starts, don’t switch to the direct gear too early.
6. When the engine is overloaded and exploded, closing the throttle valve can also reduce the knock.
