Compression Check: Testing and Inspection

COMPRESSION
CHECK 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) Check the 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.
Standard 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)

NOTICE:
^ Always use a fully charged battery to obtain an engine speed of 250 rpm or more.
^ Check the other cylinder's compression pressure in the same way.
^ This measurement must be done as quickly as possible.

If the cylinder compression is low, pour a small amount of engine oil into the cylinder through the spark plug hole and inspect again.

HINT:
^ If adding oil increases the compression, the piston rings and/or cylinder bore may be worn or damaged.
^ If pressure stays low, a valve may be stuck or seated improperly, or there may be leakage in 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.