Compression Check: Testing and Inspection

1. Before checking compression, check the engine oil level. Make sure the starter motor and battery are in normal operating condition.
2. Start the engine and wait until engine coolant temperature reaches 80-95° C (176-205° F).
3. Stop the engine and disconnect the spark plug cables.
4. Remove the spark plugs.
5. Crank the engine to remove any foreign objects in the cylinders.





6. Screw the compression gauge into the spark plug hole.
7. Fully open the throttle.
8. Crank the engine and read the gauge.
Standard value [at 250-400rpm]: 14.5 kg/cm2 (1.47 Mpa, 213 psi)
Limit: 13 kg/cm2 (1.37 Mpa, 199 psi)
9. Repeat steps 6 through 8 on all cylinders, making sure that the pressure differential for each of the cylinders is within the specified limit.
Limit: Max: 1.0 kg/cm2 (100 kpa, 14 psi) between cylinders.
10. If a cylinder's compression or pressure differential is below the specification, add a small mount of oil through the spark plug hole and repeat steps 6 through 9.
1) If the addition of oil brings the compression up, it is possible that there is wear between the piston ring and cylinder wall.
2) If compression remains the same, valve seizure, poor valve seating or a compression leak from the cylinder head gasket are all possible causes.
3) Reinstall the spark cables.

Tightening torque:
Spark plug: 20-30 Nm (200-300 kg.cm, 15-21 ft. lbs.)