Purpose, Function
The hydraulic variable valve timing actuator operates according to the hydraulic pressure and changes the phases of the exhaust camshaft. As a result, the open/close period of the exhaust valve is changed, optimized valve timing in accordance with driving conditions is realized, and the output and combustion efficiency is improved.
Construction
The hydraulic variable valve timing actuator is installed to the exhaust camshaft.
The hydraulic variable valve timing actuator has an assist spring to move the rotor in the advance direction while the engine is stopped.
Operation
At engine start
Because the stopper pin in the hydraulic variable valve timing actuator is engaged with the rotor at the maximum advance position by the spring force, the camshaft sprocket and camshaft are rotated as a single unit.
Retarding valve timing
Engine oil is lead to the retard oil passage by the OCV to apply oil pressure to the stopper pin and retard chamber. As a result, the engagement of the stopper pin is released, the rotor connected to the camshaft rotates in the retard direction against the camshaft sprocket driven by the crankshaft, and the valve timing is retarded.
Advancing valve timing
Engine oil is lead to the advance oil passage by the OCV to apply oil pressure to the advance chamber. As a result, the rotor connected to the camshaft rotates in the advance direction against the camshaft sprocket driven by the crankshaft, and the valve timing is advanced.
Maintaining intermediate valve timing
The retard and advance oil passages is closed by the OCV. As a result, the relative angle of the rotor and camshaft sprocket is maintained at a constant to hold the valve timing.
Hydraulic Variable Valve Timing Actuator Inspection
MechanicalCargo Compartment Light Bulb Removal/Installation
1. Disconnect the negative battery cable..
CAUTION:
Always disconnect the negative battery cable before performing the cargo
compartment light bulb removal. Otherwise, the circuit may be shorted resulting
in damage to the related parts such as the rear body control module (RBCM).
...
Shift And Select Mechanism [C66 M R]
Purpose, Function
The shift and select mechanism moves the shift fork to change gears according
to the operation of the shift lever in the cabin.
Construction
Shift control module
The moving parts of the shift control module are vertically positioned..
In th ...
Positive Crankcase Ventilation (PCV) System
Purpose, Outline
Prevents release of blow-by gas (unburnt gas) into the atmosphere.
The intake manifold vacuum introduces blow-by gas to the intake manifold
via the PCV valve and the ventilation hose.
System Diagram
Structure
The positive crankcase ventilation sys ...