Nissan 100NX N14 silhouetteN14

Measurement of Compression Pressure

EM-19prose procedure

Step 3 differs: 'Except for GA16DE' models disconnect fuel cut solenoid valve connector; GA16DE models release fuel pressure per EF & EC section.

COMPRESSION PRESSURE

Measurement of Compression Pressure

  1. 1
    Warm up engine.
  2. 2
    Turn ignition switch off.
  3. 3
    Except for GA16DE models: Disconnect fuel cut solenoid valve connector. GA16DE models: Release fuel pressure. Refer to 'Releasing Fuel Pressure' in section EF & EC.
    'Except for GA16DE' — engine view showing the fuel cut solenoid valve with an arrow pointing to its connector to be disconnected.
    SEM394D
  4. 4
    Remove all spark plugs.
  5. 5
    Disconnect distributor center cable.
  6. 6
    Attach a compression tester to No. 1 cylinder.
    Engine view showing a compression tester attached to the No. 1 cylinder spark plug hole with the gauge/hose routed across the engine.
    SEM149D
  7. 7
    Depress accelerator pedal fully to keep throttle valve wide open.
  8. 8
    Crank engine and record highest gauge indication.
  9. 9
    Repeat the measurement on each cylinder as shown above.
    Always use a fully-charged battery to obtain specified engine revolution.
  10. 10
    If cylinder compression in one or more cylinders is low, pour a small amount of engine oil into cylinders through spark plug holes and retest compression.
    If adding oil helps compression, piston rings may be worn or damaged. If so, replace piston rings after checking piston.
    If pressure stays low, a valve may be sticking or seating improperly. Inspect and repair valve and valve seat. (Refer to S.D.S.) If valve or valve seat is damaged excessively, replace them.
    If compression in any two adjacent cylinders is low and if adding oil does not help compression, there is leakage past the gasket surface. If so, replace cylinder head gasket.
Compression pressure - Standard
1,324 (13.24, 13.5, 192)/350kPa (bar, kg/cm², psi)/rpm
Compression pressure - Minimum
1,128 (11.28, 11.5, 164)/350kPa (bar, kg/cm², psi)/rpm
Difference limit between cylinders
98 (0.98, 1.0, 14)/350kPa (bar, kg/cm², psi)/rpm

See also

Releasing Fuel Pressure (EF & EC) · S.D.S.

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