Mitsubishi Montero (2002-2004). Manual — part 449

CYLINDER HEAD AND VALVES

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ENGINE OVERHAUL

11B-29

Required Special Tools:

• MD998051: Cylinder Head Bolt Wrench

• MD998772: Valve Spring Compressor

• MD998774: Valve Stem Seal Installer

REMOVAL SERVICE POINTS

.

<<A>> CYLINDER HEAD BOLT REMOVAL
Use special tool MD998051 to loosen the cylinder head bolt.

.

<<B>> RETAINER LOCK REMOVAL
1. Using special tool MD998772, compress the spring.
2. Remove the retainer locks.

INSTALLATION SERVICE POINTS

.

>>A<< VALVE STEM SEAL INSTALLATION
1. Install the valve spring seat.

CAUTION

• Valve stem seals for intake valves and for exhaust

valves are different. Be sure to install the correct ones.

• Valve stem seal identification color

Intake: GRAY
Exhaust: GRAY GREEN

AKX00616

MD998051

AB

AKX00617

MD998772

AB

AKX00642

EXHAUST

RUBBER COLOR:
GRAY

RUBBER COLOR:
GRAY GREEN

INTAKE

AB

CYLINDER HEAD AND VALVES

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ENGINE OVERHAUL

11B-30

CAUTION

Always use the special tool to install the valve stem seal.
Improperly installed valve stem seals may leak oil.
2. Using special tool MD998774, install a new stem seal to the

valve guide.

.

>>B<< VALVE SPRING INSTALLATION
Install the valve spring end with its identification color toward
the spring retainer.

.

>>C<< RETAINER LOCK INSTALLATION
Using special tool MD998772, compress the valve spring and
insert the retainer lock into position.

.

AKX00618AB

MD998774

AKX00718

SPRING SEAT

SPRING
RETAINER

IDENTIFI-
CATION
COLOR

STEM SEAL

AB

AKX00617

MD998772

AB

CYLINDER HEAD AND VALVES

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ENGINE OVERHAUL

11B-31

>>D<< CYLINDER HEAD BOLT INSTALLATION

CAUTION

Attach the head bolt washer in the direction shown in the
figure.
1. Tighten the bolts in two three stages in the illustrated

sequence.

Tightening torque: 108

± 5 N⋅m (80 ± 4 ft-lb)

2. Back off the bolts once and tighten them to the specified

torque in the same procedure as shown in step (1).

INSPECTION

M1113007000282

.

CYLINDER HEAD
1. Check the cylinder head gasket surface for flatness by using

a straightedge in the directions of A through G shown in the
illustration.

Standard value: 0.03 mm (0.0012 inch)
Limit: 0.2 mm (0.007 inch)

2. If the service limit is exceeded, correct to meet the

specification.

Grinding limit: *0.2 mm (0.007 inch)

3. *If the service limit is exceeded, correct to meet the

specification.

Cylinder head height (specification when new):
120 mm (4.7 inches)

.

AKX01452AB

FRONT

MD998051

HEAD
BOLT
WASHER

RIGHT
BANK

LEFT
BANK

AKX00733

CYLINDER HEAD AND VALVES

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ENGINE OVERHAUL

11B-32

VALVE
1. Check the valve face for correct contact. If incorrect, reface

using a valve refacer. The valve should make a uniform
contact with the seat at the center of the valve face.

2. If the margin exceeds the service minimum limit, replace the

valve.

Standard value:
<Intake> 1.0 mm (0.04 inch)
<Exhaust> 1.2 mm (0.05 inch)
Minimum limit:
<Intake> 0.5 mm (0.02 inch)
<Exhaust> 0.7 mm (0.03 inch)

3. Measure the valve's total length. If the measurement is less

than specified, replace the valve.

Standard value:
<Intake> 110.30 mm (4.343 inches)
<Exhaust> 114.11 mm (4.493 inches)
Minimum limit:
<Intake> 109.80 mm (4.323 inches)
<Exhaust> 113.61 mm (4.473 inches)

.

VALVE SPRINGS
1. Measure the free height of the spring and, if it is smaller than

the minimum limit, replace the spring.

Standard value: 51.0 mm (2.01 inches)
Minimum limit: 50.0 mm (1.97 inches)

2. Measure the squareness of the spring and, if the limit is

exceeded, replace the spring.

Standard value: 2

° or less

Limit: 4

°

.

VALVE GUIDES
Measure the clearance between the valve guide and valve
stem. If the limit is exceeded, replace the valve guide, valve, or
both.

Standard value:
<Intake> 0.02

− 0.05 mm (0.0008 − 0.0019 inch)

<Exhaust> 0.04

− 0.07 mm (0.0016 − 0.0027 inch)

Limit:
<Intake> 0.10 mm (0.003 inch)
<Exhaust> 0.15 mm (0.005 inch)

.

AKX00619

MARGIN

VALVE SEAT
CONTACT

AB

AKX00624

AKX00607

2˚

FREE
HEIGHT

AB

AKX00714

VALVE
GUIDE

STEM OUTSIDE
DIAMETER

GUIDE INSIDE DIAMETER

AB