Mazda 2006 MX-5 Service Highlights page 65

Retarding valve timing
• When the spool valve in the oil control valve (OCV) moves to the right according to the PCM signal, hydraulic
pressure, from the oil pump, feeds into the valve timing retard passage and finally to the valve timing retard
chamber in the variable valve timing actuator. Then, the rotor integrated with the camshaft rotates in the valve
timing retard direction, against the housing driven by the crankshaft, and valve timing is retarded.
HYDRAULIC PRESSURE FLOW
OIL PUMP
OIL PAN
HOUSING
Maintaining intermediate valve timing
• The spool valve in the oil control valve (OCV) is located near the middle of the valve timing advance and retard
positions. Because of this, hydraulic pressures are maintained in both valve timing advance and retard
chambers of the variable valve timing actuator. At the same time, relative angles of the rotor and the housing
are fixed and maintained, resulting in fixed valve timing.
HYDRAULIC PRESSURE FLOW
TO VALVE TIMING
ADVANCE CHAMBER
End Of Sie
MECHANICAL
FROM VALVE TIMING
ADVANCE CHAMBER
VALVE TIMING
RETARD CHAMBER
ROTOR
VARIABLE VALVE TIMING ACTUATOR
OIL PUMP
OIL CONTROL VALVE (OCV)
TO VALVE TIMING
RETARD CHAMBER
SPOOL VALVE
OIL CONTROL VALVE (OCV)
TO VALVE TIMING
RETARD CHAMBER
CAMSHAFT
PCM
01–10
PCM
E5U110ZT5033
E5U110ZT5034
01–10–19