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Compression check

Hint

If there is lack of power, excessive oil consumption or poor fuel economy, measure the compression pressure.

  1. Warm up and stop engine.

    Allow the engine to warm up to normal operating temperature.

  2. (3S-GTE) Disconnect solenoid resistor connector.

  3. Disconnect cold start injector connector.
  4. Disconnect distributor connector.
  5. Remove spark plugs. (See On-vehicle inspection (3S-GTE) › Inspection of high-tension cords)

  6. Check cylinder compression pressure.

    1. Insert a compression gauge into the spark plug hole.
    2. Fully open the throttle.

    3. While cranking the engine, measure the compression pressure.

      Hint

      Always use a fully charged battery to obtain engine speed of 250 rpm or more.

    4. Repeat steps (a) through © for each cylinder.

      Notice

      This measurement must be done in as short a time as possible.

      Compression pressure:

      • 3S-GTE – 11.5 kg/cm² (164 psi, 1,128 kPa) or more
      • 5S-FE – 12.5 kg/cm² (178 psi, 1,226 kPa) or more

      Minimum pressure:

      • 3S-GTE – 9.0 kg/cm² (128 psi, 883 kPa)
      • 5S-FE – 10.0 kg/cm² (142 psi, 981 kPa)

      Difference between each cylinder: 1.0 kg/cm² (14 psi, 98 kPa) or less

    5. If the cylinder compression in one or more cylinders are low, pour a small amount of engine oil into the cylinder through the spark plug hole and repeat steps (a) through © for cylinders with low compression.

      • If adding oil helps the compression, chances are that the piston rings and/or cylinder bore are worn or damaged.
      • If pressure stays low, a valve may be sticking or seating is improper, or there may be leakage past the gasket.

  7. Reinstall spark plugs. (See On-vehicle inspection (3S-GTE) › Inspection of spark plugs)

    Torque: 180 kg-cm (13 ft-lb, 18 N·m)

  8. Reconnect distributor connector.

  9. Reconnect cold start injector connector.
  10. (3S-GTE) Reconnect solenoid resistor connector.