Engine Compression: Inspection

NOTE: If there is lack of power, excessive oil consumption or poor fuel economy, measure the compression pressure.
The measurement of compression pressure should be performed in the Cranking Mode.

Warm Up And Stop Engine
Allow the engine to warm up to normal operating temperature.
Remove Air Cleaner Assembly
Remove IGNITION COIL .
Remove Spark Plugs
Connect Toyota Hand-Held Tester
1. Connect the TOYOTA hand-held tester to the DLC3.
  
  Fig 1: Connecting TOYOTA Hand-Held Tester To DLC3 Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Select the cranking mode on the TOYOTA hand-held tester.
3. Please refer TOYOTA hand-held tester operator's manual for further details.
Inspect 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.
4. Repeat steps (a) through (c) for each cylinder.
  
  Fig 2: Inserting Compression Gauge Into Spark Plug Hole
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  NOTE: This measurement must be done in as short a time as possible.
  
  Compression pressure:
  
  728 kPa (7.4 kgf/cm ² , 106 psi)
  
  Minimum pressure:
  
  534 kPa (5.4 kgf/cm ² , 77 psi)
  
  Difference between each cylinder:
  
  98 kPa (1.0 kgf/cm ² , 14 psi) or less
5. If the cylinder compression in one more cylinders is low, pour a small amount of engine oil into the cylinder through the spark plug hole and repeat steps (a) through (c) for cylinders with low compression.
  - If adding oil helps the compression, it is likely 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.
Reinstall Spark Plugs
Reinstall IGNITION COIL .