Compression Check: Testing and Inspection

INSPECT COMPRESSION
a. Remove the V-bank cover.
b. Remove the air cleaner inlet and intake air pipe.
c. Disconnect the throttle control motor connector.
d. Remove the oil level gauge guide.
e. Remove the 8 ignition coils.
f. Remove the 8 spark plugs.
g. Disconnect the 8 injector connectors.
h. Inspect the cylinder compression pressure.
1. Insert a compression gauge into the spark plug hole.
2. Fully open the throttle forcibly by hand.
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 (1) through (3) for each cylinder.

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

Compression pressure: 1,226 kPa (12.5 kgf/cm2, 178 psi) or more
Minimum pressure: 981 kPa (10.0 kgf/cm2, 142 psi)
Difference between each cylinder: 98 kPa (1.0 kgf/cm2, 14 psi) or less
5. 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.
i. Connect the 8 injector connectors.
j. Install the 8 spark plugs.
k. Install the 8 ignition coils.
l. Install the oil level gauge guide.
m. Connect the throttle control motor connector.
n. Install the air cleaner inlet and intake air pipe.
o. install the V-bank cover.