1. Valve Problems:
- Burnt, worn, or damaged valves can lead to improper sealing, causing a loss of compression.
- Bent, broken, or stuck valve stems can also prevent the valve from closing properly.
2. Piston Rings:
- Worn, damaged, or broken piston rings may allow combustion gases to leak past them, resulting in reduced compression.
- Improperly installed piston rings can have the same effect.
3. Cylinder Bore:
- A damaged cylinder bore, such as scratches or excessive wear, can cause compression loss as the piston cannot seal against the cylinder wall.
4. Head Gasket Failure:
- A blown or damaged head gasket can create a breach between the cylinder and a coolant or oil passage, allowing combustion gases to escape.
5. Improper Timing:
- If the timing between the piston and the opening/closing of the valves is incorrect, it can affect the compression process and result in no compression.
6. Mechanical Damage:
- Severe engine damage, such as a cracked piston, broken connecting rod, or damaged cylinder head, can lead to a loss of compression.
