Compression Test
- Before checking engine compression, check the engine oil level. Also check that the starter motor and battery are all in normal operating condition.
- Check the DTC and note it. Use the scan tool to clear the ECM'S memory.
- Start the engine and wait until engine coolant temperature reaches 80-90°C (176-205°F).
- Disconnect the fuel pump connector.
- Turn off engine and disconnect the spark plug cables.
- Remove the spark plugs.
- Disconnect the ignition Coil connector.
- Crank the engine to remove any foreign material in the cylinders.
- Insert the compression gauge into the spark plug hole.
- Depress the accelerator pedal to open the throttle fully.
- Crank the engine and read the gauge.
Standard value : 1275 kpa (13.0 kg/cm2 , 185 psi)
Limit : 1128 kpa (11.5 kg/cm2 , 164 psi)
- Repeat steps 9 to 11 over all cylinders, ensuring that the pressure differential for each of the cylinders is within the specified limit.
Limit :
Max 98 kpa (1.0 kg/cm2 , 14 psi) between cylinders
- If a cylinder's compression or pressure differential is outside the specification, add a small amount of oil through the spark plug hole, and repeat steps 9 to 12.
- If the addition of oil makes the compression to rise, it is likely that there may be wear between the piston ring and cylinder wall.
- If compression remains the same, valve seizure, poor valve seating or a compression leak from the cylinder head gasket are all possible causes.
Tightening torque
Spark plug : 19.6-29.4 Nm (2-3 kg.m, 14.5-21.7 lb.ft)