valve is a one-piece forging, while the exhaust valve
has a forged head with a welded stem for lock groove
hardenability. Both valves employ a three-groove lock
design.
VALVE SPRINGS
Valve springs are unique for intake versus exhaust.
Both are made from chrome silicon alloy wire and
incorporate a “bee-hive” design. Valve spring retain-
ers and locks are common. The valve spring seat is
integral with the valve stem oil seal, which incorpo-
rates a garter spring to maintain consistent lubrica-
tion control to the valve stem.
INTAKE MANIFOLD
The composite intake manifold is a cross-flow type
with long runners to improve air charge inertia. An
active Short Runner Valve (SRV) opens during cer-
tain operating conditions to improve top end perfor-
mance. A Manifold Tuning Valve (MTV) connects the
plenums at specific engine speeds to maximize low
RPM torque without reducing high RPM power.
EXHAUST MANIFOLDS
Both manifolds are a log style made of ductile cast
iron. The outlets are designed for V-Band clamp
attachment of close coupled catalytic converters.
ENGINE LUBRICATION
System is a full-flow filtration, pressure feed type.
The oil pump body is mounted to the engine block.
The pump inner rotor is driven by the crankshaft. A
windage tray, integral with the oil pan gasket,
increases power by minimizing oil windage at high
engine RPM. For increased oil cooling, an oil-to-cool-
ant oil cooler is used. This cooler is mounted inside
the radiator tank.
DIAGNOSIS AND TESTING
HYDRAULIC LASH ADJUSTER
The hydraulic lash adjusters are precision units
installed in machined openings in the valve actuating
ends of the rocker arms. Do not disassemble the
hydraulic lash adjuster from the rocker arm
assembly (Fig. 3). Damage to the adjuster and
rocker arm will occur.
CHECKING ENGINE OIL PRESSURE
Check oil pressure using gauge at oil pressure
switch location. Oil pressure should be 34 kPa (5 psi)
at idle or 205 to 550 kPa (30 to 80 psi.) at 3000 RPM.
(1) Remove pressure sending unit. The pressure
sending unit is located on the left front of engine
near the oil filter.
(2) Install oil pressure gauge.
CAUTION:
If oil pressure is 0 at idle, Do Not Run
engine at 3000 RPM.
(3) Warm engine to normal operating temperature.
TESTING VALVE SPRINGS
VALVE SPRING IDENTIFICATION
The valve springs are of two different lengths and
are wound in different directions. The valve springs
are color coded, intake spring is right hand coil direc-
tion with orange dye on the top coils and the exhaust
spring is left hand coil direction with a green dye on
the top coils (Fig. 4).
TESTING VALVE SPRINGS
Whenever valves have been removed for inspection,
reconditioning or replacement, valve springs should
be tested (Fig. 5). As an example; the compression
length of the spring to be tested is 38.00 mm (1.496
inches.). Turn table of Tool C-647 until surface is in
line with the 38.00 mm (1.496 inches.) mark on the
threaded stud and the zero mark on the front. Place
spring over stud on the table and lift compressing
lever to set tone device. Pull on torque wrench until
ping is heard. Take reading on torque wrench at this
instant. Multiply this reading by two. This will give
the spring load at test length. Fractional measure-
ments are indicated on the table for finer adjust-
ments. Refer to Specifications Section to obtain
Fig. 3 Hydraulic Lash Adjuster
Fig. 4 Valve Spring Identification
LH
3.2L ENGINE
9 - 67
DESCRIPTION AND OPERATION (Continued)