Compression Check

FA20 ENGINE MECHANICAL: ENGINE: ON-VEHICLE INSPECTION; 2013 MY FR-S [03/2012 -]

Inspect the cylinder compression pressure.

(1) While cranking the engine, measure the compression pressure.

HINT
Always use a fully charged battery to obtain an engine speed of 250 rpm or more.

NOTICE:
The measurement must be performed as quickly as possible.

Standard compression pressure:

1750 kPa (17.8 kgf/cm2, 254 psi) or higher

Minimum pressure:

1150 kPa (11.7 kgf/cm2, 167 psi)

Difference between each cylinder:

200 kPa (2.0 kgf/cm2, 29 psi) or less

HINT
If the cylinder compression is low, pour a small amount of engine oil into the cylinder through the spark plug hole and inspect the compression again. Then perform the 2 steps above for the cylinders with low compression.

* If adding oil increases the compression, the piston rings and/or cylinder bore may be worn or damaged.

* If the pressure stays low, a valve may be stuck or seated improperly, or there may be leakage from the gasket.