4 Runner 4WD V6-4.0L (1GR-FE) (2006)
Compression Check: Testing and Inspection
INSPECT COMPRESSION
a. Remove the V-bank cover.
b. Remove the air cleaner assembly.
c. Remove the intake air surge tank.
d. Remove the 6 ignition coils.
e. Remove the 6 spark plugs.
f.
Disconnect the 6 injector connectors.
g. Inspect the cylinder compression pressure.
1
Insert a compression gauge into the spark plug hole.
2
Fully open the throttle 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 through (1) to (3) for each cylinder.
NOTICE: This measurement must be done as quickly as possible.
Compression pressure: 1.3 MPa (13.3 kgf/cm2, 189 psi) or more
Minimum pressure: 1.0 MPa (10.2 kgf/cm2, 145 psi)
Difference between each cylinder: 0.1 MPa (1.0 kgf/cm2, 15 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 through (1) to (3) 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 a leakage through the gasket.
h. Connect the 6 injector connectors.
i.
Install the 6 spark plugs.
j.
Install the 6 ignition coils.
k. Install the intake air surge tank.
l.
Install the air cleaner assembly.
m. Install the V-bank cover.