Repair Procedures

Compression Pressure Test

If engine power is insufficient, oil consumption is excessive, or fuel economy is poor, measure the compression pressure.

1. 1
   Warm up and stop the engine. Allow the engine to warm up to normal operating temperature.
2. 2
   Disconnect the injector connectors (A).

   

3. 3
   Remove the spark plugs. (Refer to Engine Electrical System - "Spark Plug")
4. 4
   Check the compression pressure in the cylinder.

   1. Insert the compression gauge into the spark plug hole.

      

   2. Fully open the throttle valve.
   3. While cranking the engine, measure the compression pressure.

      Always use a fully charged battery to make sure the engine cranking speed is 200 rpm or more.

   4. Repeat steps (1) through (3) for each cylinder.

      This measurement must be done as quickly as possible.

      Compression pressure: 1275 kPa (13.0 kgf/cm², 185 psi) Minimum pressure: 1128 kPa (11.5 kgf/cm², 164 psi) Difference between each cylinder: 100 kPa (1.0 kgf/cm², 15 psi) or less
   5. If compression is low in one or more cylinders, pour a small amount of engine oil through the spark plug hole into the cylinder and repeat steps (1) through (3) for the cylinders with low compression.

      A.	If adding oil improves compression, the piston rings and/or cylinder bore are likely worn or damaged.

      B.	If pressure remains low, a valve may be sticking or seating improperly, or there may be leakage past the head gasket.

5. 5
   Install the remaining parts in the reverse order of removal.
6. 6
   Some DTCs may remain after the inspection test and may need to be cleared manually using GDS.