What about abnormal noise of Beiqi Saab x35 engine?

Cause of abnormal sound of Beiqi Saab x35 engine: 1. Abnormal sound of piston knocking on cylinder. The so-called abnormal sound of piston knocking on the cylinder refers to the abnormal sound produced by the piston side slapping the cylinder wall. Generally speaking, when the direction of the axial force generated at the top of the piston changes from the compression stroke to the power stroke with the piston, the piston knocks abnormally. 2. Crankshaft bearing (big tile) and connecting rod bearing (small tile) have abnormal sound. These two kinds of abnormal sounds can be distinguished from sound position and sound frequency. Generally, the big tile has a low voice and the small tile has a high voice. Secondly, it can be distinguished by the broken cylinder, because when some small tiles make abnormal noise, if the broken cylinder is ignited or injected with oil, the abnormal noise will weaken or disappear; If the tile rings, the sound will only weaken or remain unchanged when the cylinder breaks, but it will never disappear; 3. Abnormal noise in the air intake and exhaust system. When the intake manifold leaks air, the engine will produce noise when idling, and the noise will be aggravated with the increase of engine speed; When the exhaust manifold leaks air, a sudden explosion will be heard when the engine accelerates; 4. When the air filter is blocked, the engine will feel stuffy, and it will produce abnormal noise when accelerating; When the exhaust system is blocked and the engine accelerates, sometimes there will be tempering explosion; When the air flowmeter leaks air from the rubber hose to the throttle valve, it will also produce tempering sonic boom when it accelerates rapidly.