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.
Cooling System
Outline
Passing water resistance is reduced by improvement of the engine coolant
passage shape.
Pump efficiency is improved by changing the water pump impeller to the closed
impeller.
Structural View
Flow Chart
Structure
Consists of the followi ...
Seat Weight Sensor Control Module Removal/Installation [Two Step Deployment
Control System]
CAUTION:
When the seat weight sensor control module is replaced with a new one, perform
the seat weight sensor calibration using the M?MDS..
1. Switch the ignition to off.
2. Disconnect the negative battery cable and wait for 1 min or more..
3. Disconnect the connectors.
...
Service Publications
Service Publications
Factory-authorized Mazda service publications are available for owners who wish
to do some of their own maintenance and repair.
When requesting any of our publications through an Authorized Mazda Dealer, refer
to the chart below.
If they do not have what you need in stock ...