* Rod knock: This is a loud knocking sound that occurs when the piston rod bearings are worn or damaged. It is usually caused by low oil pressure or a lack of lubrication.
* Piston slap: This is a quieter knocking sound that occurs when the piston moves up and down in the cylinder. It is usually caused by excessive clearance between the piston and the cylinder wall.
* Spark knock: This is a high-pitched knocking sound that occurs when the fuel in the engine ignites too early. It is usually caused by low-octane fuel, a faulty spark plug, or a problem with the engine timing.
* Valve knock: This is a clicking sound that occurs when the valves in the engine are not properly adjusted. It is usually caused by excessive wear or damage to the valve train.
* Wrist pin knock: This is a sharp knocking sound that occurs when the wrist pin, which connects the piston to the connecting rod, is worn or damaged. It is usually caused by low oil pressure or a lack of lubrication.
