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The camshaft position actuator oil control valve (OCV)
directs oil from the oil feed in the head to the appropriate
camshaft position actuator oil passages. There is one
OCV for each camshaft position actuator. The OCV is
sealed and mounted to the front cover. The ported end
of the OCV is inserted into the cylinder head with a
sliding fit. A filter screen protects each OCV oil port from
any contamination in the oil supply.
The camshaft front journal has several drilled oil holes to
allow camshaft position actuator control oil to transfer
from the cylinder head to the camshaft position actuator.
The center camshaft bolt hole is counterbored to allow
oil to flow around the camshaft bolt and to the camshaft
position actuator. Oil in this oil passage is used to move
the camshaft position actuator to the default or home
position. Radially outward from the center of the journal
is a set of four drilled camshaft position actuator oil
holes. Oil in this group of oil holes is used to move the
camshaft from the default position to a specific set
position as determined by the ECM. Seal rings are used
at the front and rear of the front camshaft journal to
prevent oil leakage from the camshaft position actuator
hydraulic system. The seal is made from a plastic
compound that resists wear and has a diagonal end gap
to enhance sealing. The camshaft position actuator is
mounted to the front end of the camshaft and the timing
notch in the nose of the camshaft aligns with the dowel
pin in the camshaft position actuator to ensure proper
cam timing and camshaft position actuator oil hole
alignment.
Cylinder Heads
The cylinder heads are semi permanent mold cast
aluminum with powdered metal valve seat inserts and
valve guides. Two 36.96 mm (1.4551 in) intake valves
and two 30.60 mm (1.2047 in) exhaust valves are
actuated by roller finger followers pivoting on a
stationary hydraulic lash adjuster (SHLA). Separate
exhaust and intake camshafts are supported by four
bearings machined into the cylinder head. The front
camshaft bearing cap is used as a thrust control surface
for each camshaft. Each spark plug is shielded by a tube
that is pressed into the cylinder head. Each spark plug
ignition coil is also mounted through the spark plug tube.
The engine coolant temperature (ECT) sensor is
threaded into the left cylinder head.
Induction System
The intake manifold consists of two cast aluminum
components. Two short bolts in the lower intake manifold
and four long bolts, that pass through both manifolds,
mount the intake manifold assembly to the cylinder
heads. Additionally two bolts mount the upper intake
manifold to the lower intake manifold. The throttle body,
Evaporative Emissions (EVAP) solenoid and tubes,
Positive Crankcase Ventilation (PCV) tubes, and brake
booster hose are mounted to the upper intake manifold.
The fuel injector wiring harness, fuel rail assembly, and
fuel injectors are mounted to the lower intake manifold.
Right and Left Bank Designation
Right hand (RH) and left hand (LH) designation through
the engine mechanical section are viewed from the rear
of the engine or from inside the vehicle.
Cleanliness and Care
An automobile engine is a combination of many of the
following surfaces:
• Machined
• Honed
• Polished
• Lapped
The tolerances of these surfaces are measured in the
ten-thousandths of an inch. When you service any
internal engine part, cleanliness and care are important.
Apply a liberal coating of engine oil to the friction areas
during assembly in order to protect and lubricate the
surfaces on initial operation. Throughout this section,
practice proper cleaning and protection procedures to
the machined surfaces and to the friction areas.
CAUTION
!
Engine damage may result if an abrasive
paper, pad, or motorized wire brush is used
to clean any engine gasket surfaces.
Whenever you remove the valve train components, keep
the components in order. Follow this procedure in order
to install the components in the same locations and with
the same mating surfaces as when removed.
WARNING
!
Refer to "Battery Disconnect Caution: ".
Disconnect the negative battery cables before you
perform any major work on the engine.
Separating Parts
In addition to the room temperature vulcanizing (RTV)
sealant's sealing capabilities, the RTV sealants may
form an adhesive bond between the components. This
may make the components difficult to remove or to
separate. If possible, bump the components sideways
rather than using prying tools in order to remove the
components. This technique prevents damage when the
bonding strength of the RTV sealant is stronger than the
component itself. Perform bumping at the bends or at
the reinforced areas in order to prevent part distortion.
Engine Mechanical:
1D-3
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Troubleshooting
