1. Worn or damaged engine bearings: Engine bearings are responsible for reducing friction between moving parts in the engine. If they become worn or damaged, they can cause a knocking sound.
2. Low oil level: If the oil level is low, it can cause the engine to become oil-starved. This can lead to increased friction and a knocking sound.
3. Damaged or loose spark plugs: If spark plugs are damaged or loose, they can cause a knocking sound.
4. Carbon deposits on the valves: Carbon deposits can build up on the valves over time, which can cause a knocking sound.
5. Worn or damaged timing chain or belt: The timing chain or belt synchronizes the movement of the pistons and valves in the engine. If it becomes worn or damaged, it can cause a knocking sound.
6. Piston slap: Piston slap occurs when the pistons are loose in the cylinders. This can cause a knocking sound that is most noticeable when the engine is cold.
If you hear a loud knocking sound in the engine compartment, it is important to have it diagnosed by a qualified mechanic as soon as possible to prevent further damage to the engine.
