EM0EH−03
S01361
Compression
Gauge
− ENGINE MECHANICALCOMPRESSION
EM−3
1996 RAV4 (RM447U)
COMPRESSION
INSPECTION
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. DISCONNECT DISTRIBUTOR CONNECTOR
3. DISCONNECT HIGH−TENSION CORDS FROM SPARK
PLUGS AND IGNITION COIL
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 pos-
sible.
Compression pressure:
1,275 kPa (13.0 kgf/cm
2, 185 psi) or more
Minimum pressure: 932 kPa (9.5 kgf/cm
2, 135 psi)
Difference between each cylinder:
98 kPa (1.0 kgf/cm
2, 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, 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.
6. REINSTALL SPARK PLUGS
7. RECONNECT HIGH−TENSION CORDS TO SPARK
PLUGS AND IGNITION COIL
