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