Here are some possible causes of low compression in cylinder 3:
- Leaky piston ring: A leaky piston ring can allow air-fuel mixture to escape past the piston, reducing compression.
- Leaky valve: A leaky intake or exhaust valve can also allow air-fuel mixture to escape, reducing compression.
- Damaged cylinder head gasket: A damaged cylinder head gasket can allow coolant or oil to leak into the cylinder, reducing compression.
- Scored cylinder wall: A scored cylinder wall can allow air-fuel mixture to escape past the piston, reducing compression.
To determine the exact cause of low compression in cylinder 3, you will need to perform a cylinder leak down test. This test will help you identify the source of the leak and allow you to determine the best course of action for repairing it.
Here are the steps involved in performing a cylinder leak down test:
- Remove the spark plug from the cylinder in question.
- Insert a cylinder leak down tester into the spark plug hole.
- Connect the air compressor to the cylinder leak down tester.
- Set the air compressor to 100 psi.
- Observe the cylinder leak down tester gauge. If the gauge reads 0%, then the cylinder is not leaking. If the gauge reads higher than 0%, then the cylinder is leaking.
- Listen for the source of the leak. If you hear air escaping from the exhaust pipe, then the exhaust valve is leaking. If you hear air escaping from the intake manifold, then the intake valve is leaking. If you hear air escaping from the crankcase, then the piston rings are leaking.
- Once you have identified the source of the leak, you can take the appropriate steps to repair it.
