The abnormal sound of the piston ring mainly includes the metal knocking sound of the piston ring, the leakage sound of the piston ring and the abnormal sound caused by excessive carbon deposition.
3. Knocking sound
Cylinder knocking refers to the oscillation of the piston in the cylinder at the moment when the piston starts its working stroke, or when the piston goes up.
The abnormal sound of "dangdang" or "click" caused by the collision of its head and skirt with the cylinder wall.
If it is a "dangdang" sound, it is mostly caused by poor lubrication of the cylinder wall. At this time, you can drop a little oil into the cylinder and restart the engine. If the abnormal sound is reduced or disappeared, it means that the abnormal sound is indeed caused by poor lubrication. If it is a "click" sound and blue smoke is emitted from the exhaust pipe, it is generally due to the excessive clearance between the piston and the cylinder wall.