Mitsubishi Outlander XL. Manual — part 1236

MITSUBISHI INNOVATIVE VALVE TIMING AND LIFTING ELECTRONIC CONTROL

SYSTEM (MIVEC)

ZK602599AA00

Intake valve

Exhaust valve

Camshaft

Piston arm assy

Rocker arm assy

T lever assy

Rocker arm assy

Rocker arm shaft

Rocker arm shaft

ZK602601

High lift cam

Middle lift cam

Low lift cam

Plug

T-lever

Wing

AA00

Intake rocker arm for
middle lift cam

Intake side

Intake rocker arm for
low lift cam

Switch-over oil pressure
(lubricating oil)

Lubricating oil

Exhaust side

Exhaust rocker arm

Switch-over
piston

MIVEC has an additional switching system on the two
intake valves in the conventional SOHC 4 valve
engine. This switching system has two cams for the
low mode having a difference between the valve-lifts
and for the high mode keeping both valve lifts high.
In the range of the low engine speed, the flow within
the valves is enhanced by the difference between the
valve-lifts. Also, the stabilization of the combustion is
designed for low fuel economy, low exhaust gas and
high torque. At high engine speeds, the high output
due to the increment in the intake air amount is
reached by increasing the open valve period and the
lift.
A T-lever moves following the high lift cams and is
arranged between the high lift cam and two rocker

arms, in addition to the low & middle lift cams and two
rocker arms that drive the two intake valves
respectively.
In the range of the low engine speed, the low and the
middle lift cams drive each valve respectively because
the wing of the T-lever moves freely. At high engine
speeds, the oil pressure moves the switch-over piston
within the rocker arm. The T-lever reaches the rocker
arm and pushes it, and then the high lift cam lifts both
valves.

ENGINE

11-13

BASE ENGINE

The cam switching is carried out when the torque
produced in the low speed mode and the one
produced in the high-speed mode crosses each other
at an engine speed. An accumulator ensures oil
pressure at the instant of switching and prevents
switching mistakes.

The oil passage is divided into two, one for the intake
rocker shaft and the other for the exhaust rocker shaft,
just in front of the oil control valve (OCV). Oil is always
supplied to the exhaust rocker shaft.
Oil supply to the intake rocker shaft is controlled by
ON/OFF of the oil control valve (OCV) and carries out
the switching for the low, middle and high lift cams.

ZK602603

Oil control
valve filter

AA00

Rocker arm piston

T-lever

Power train control
module(PCM)

Oil control
valve <OFF>

When the OCV is in the OFF position, the switch-over
piston does not operate because the switch-over oil
pressure within the intake rocker shaft is below the

specified pressure, and so the wing of the T-lever
does not reach the switch-over piston. Accordingly,
the intake valve is driven by the rocker arm for low and
middle lift cam.

11-14

ENGINE

BASE ENGINE

ZK602611

Oil control
valve filter

AA00

Power train control
module(PCM)

Oil control
valve <ON>

Rocker arm piston

T-lever

When the OCV is in the ON position, the switch-over
piston is pushed by the oil pressure because the
switch-over oil pressure within the intake rocker shaft

is above the specified pressure, and so the wing of the
T-lever reaches the switch-over piston. Accordingly,
the intake valve is driven by the T-lever.

ENGINE

11-15

BASE ENGINE

OIL FEEDER CONTROL VALVE

ZK602612AA00

Oil drain

Oil supply

Out put

Oil drain

O-ring

Terminal

Plunger

Cover

Coil

O-ring

Spool

Housing

Oil drain

The oil feeder control valve uses electromagnetic
valve mechanism to change oil pressure to rocker arm
and rocker shaft that drive MIVEC.
The oil feeder control valve uses electromagnetic
valve mechanism to change oil pressure to rocker arm
and rocker shaft that drive MIVEC.

11-16

ENGINE

BASE ENGINE