Compression Check: Testing and Inspection

ON-VEHICLE INSPECTION
1. INSPECT COMPRESSION
(a) Warm up and stop the engine.
(1) Allow the engine to warm up to a normal operating temperature.
(b) Remove the 2 nuts and throttle body cover.
(c) Remove the air cleaner hose assembly.
(d) Remove the air cleaner cap.
(e) Disconnect the 8 injector connectors and 8 ignition coils.
(f) Remove the 8 bolts and 8 ignition coils.
(g) Remove the 8 spark plugs.





(h) Check the cylinder compression pressure.

NOTE: Check each cylinder's compression pressure in the same way.

(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:
1373 kPa (14.0 kgf/cm2, 199 psi) or more
Minimum pressure:
1030 kPa (10.5 kgf/cm2, 149 psi)
Difference between each cylinder:
98 kPa (1.0 kgf/cm2, 14.2 psi) or less

NOTICE:
- Always use a fully charged battery to obtain an engine speed of 250 rpm or more.
- This measurement must be done as quickly as possible.

(4) If the cylinder compression is low in one or more cylinders, pour a small amount of engine oil into the cylinder with low compression through its spark plug hole. Then inspect the cylinder compression pressure again.

HINT:
- If adding oil helps boost 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 stuck or seated improperly, or there may be leakage in the gasket.

(i) Install the 8 spark plugs.
(j) Install the 8 ignition coils with the 8 bolts.
(k) Connect the 8 injector connectors and 8 ignition coils.
(l) Install the air cleaner cap.
(m) Install the air cleaner hose.
(n) Install the throttle body cover with the 2 nuts.