Compression Check: Testing and Inspection
INSPECTIONHINT: If there is lack of power, excessive oil consumption or poor fuel economy, measure the compression pressure.
1. WARM UP AND STOP ENGINE
2. REMOVE INTAKE AIR CONNECTOR
3. DISCONNECT HIGH-TENSION CORDS FROM SPARK PLUGS
NOTICE: Pulling on or bending the cords may damage the conductor inside.
4. REMOVE SPARK PLUGS
5. CHECK CYLINDER COMPRESSION PRESSURE
a) Insert a compression gauge into the spark plug hole.
b) Fully open the throttle.
c) While cranking the engine, measure the compression pressure.
HINT: Always use a fully charged battery to obtain engine speed of 250 rpm or more.
d) Repeat steps a) through c) for each cylinder.
NOTICE: This measurement must be done in as short a time as possible.
Compression pressure: 1,230 kPa (112.5 kgf/cm2, 178 psi) or more
Minimum pressure: 880 kPa (9.0 kgf/cm2, 127 psi)
Difference between each cylinder: 98 kPa (1.0 kgf/cm2, 14 psi) or less
e) If the cylinder compression in one or 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, chances are that the piston rings and/or cylinder bore are worn or damage.
- If pressure stays low, a valve may be sticking or seating is improper, or there may be leakage past the gasket.
6. INSTALL SPARK PLUGS
Torque: 19 Nm (200 kgf-cm, 14 ft. lbs.)
7. INSTALL HIGH-TENSION CORDS TO SPARK PLUGS
8. INSTALL INTAKE AIR CONNECTOR