1. Worn piston rings: This is the most common cause of low compression. Piston rings are responsible for sealing the combustion chamber and preventing air and fuel from escaping. Over time, the rings can become worn, allowing compressed air and fuel to leak past them. This can cause the engine to lose power, run rough, and have higher fuel consumption.
2. Damaged pistons or cylinders: If the pistons or cylinders are damaged, the engine may not be able to create enough compression. Common causes of piston damage include a hole in the piston, a cracked piston ring, or a connecting rod that is bent or out of place.
3. Valve problems: If the valves are not opening properly, air and fuel will not be allowed into the cylinder and exhaust gases will not be able to escape. This can cause the cylinder to lose compression.
4. Head gasket failure: A blown head gasket can allow coolant or oil to leak into the combustion chamber, which can cause the engine to lose compression.
5. Carbon build-up: If there is excessive carbon build-up on the piston head, valves, or cylinder walls, it can interfere with the air/fuel mixture flow, affect the valve seating and cause the engine to lose compression.
