Content .. 87 88 89 90 ..

Mitsubishi Lancer Evolution IX. Manual - part 89

CYLINDER HEAD AND VALVES

ENGINE OVERHAUL

11B-47

VALVE SPRINGS

1. Measure the free height of the spring.

Replace the spring if its height is smaller than the
limit.

Standard value: 50.4 mm
Limit: 49.4 mm

2. Measure the squareness of the spring.

Replace the spring if it is out of square beyond the
limit.

Standard value: 1.5

° or smaller

Limit: 4

VALVE GUIDE

Measure the valve guide inside diameter and valve
stem diameter to calculate the clearance between
the valve guide and valve stem.
If the limit is exceeded, replace the valve guide or
valve, or both.

Standard values:

Intake 0.02

− 0.05 mm

Exhaust 0.05

− 0.09 mm

Limits:

Intake 0.10 mm
Exhaust 0.15 mm

VALVE SEATS

With the valve installed in position and its face
pressed against the valve seat, measure the valve
stem projection (distance between the valve stem
end and spring seating surface). If the measurement
exceeds the limit, replace the valve seat.

Standard values:

Intake 49.2 mm
Exhaust 48.4 mm

Limits:

Intake 49.7 mm
Exhaust 48.9 mm

VALVE SEAT RECONDITIONING

1. Before reconditioning the valve seat, check the

clearance between the valve guide and valve
stem and, if necessary, replace the valve guide.

2. Resurface the valve seat to the indicated width

and angles.

3. After resurfacing, lap the valve and valve seat

using lapping compound.

AK300594

Out of square

Free height

AK300168

Guide inside diameter

Stem diameter

Valve
guide

AK202814

Valve stem
projection

Valve stem
end

Spring
seating
surface

AK202850

0.9 – 1.3 mm

0.9 – 1.3mm

65˚

15˚

25˚

43.5˚ – 44˚

CYLINDER HEAD AND VALVES

ENGINE OVERHAUL

11B-48

VALVE SEAT REPLACEMENT

1. Cut inside of the valve seat to be replaced until its

wall becomes thin enough for removal, then
remove the valve seat.

2. Rebore the valve seat hole in the cylinder head to

a diameter matched to the diameter of the
selected oversize valve seat.

Intake valve seat hole diameters:

0.3 oversize: 35.30

− 35.33 mm

0.6 oversize: 35.60

− 35.63 mm

Exhaust valve seat hole diameters:

0.3 oversize: 33.30

− 33.33 mm

0.6 oversize: 33.60

− 33.63 mm

3. Before fitting the valve seat, cool it in liquid

nitrogen to prevent damage to its hole in the
cylinder head due to interference.

4. Resurface the valve seat. See the VALVE SEAT

RECONDITIONING section.

VALVE GUIDE REPLACEMENT

1. Force out the valve guide toward the cylinder

block using a press.

CAUTION

Do not use a replacement valve guide of the
same size as the removed one.
2. Machine the valve guide hole in the cylinder head

to the size matched to the selected oversize valve
guide.

Valve guide hole diameters

0.05 oversize: 12.05

− 12.07 mm

0.25 oversize: 12.25

− 12.27 mm

0.50 oversize: 12.50

− 12.52 mm

3. Press-fit the valve guide until it remains protruded

above the cylinder head by the amount indicated
in the drawing.

Standard value: 19.2

− 19.8 mm

NOTE: Press the valve guide from above the cyl-
inder head.
NOTE: The valve guides for the intake valves are
different in length from those for the exhaust
valves (45.5 mm for intake valves; 50.5 mm for
exhaust valves)

4. After installing the valve guide, insert a new valve

in it to check for smooth movement.

AK300719AB

0.5

–

1 mm

0.5

–

1 mm

Cut

AK300720AB

Oversize hole diameter

Valve seat
height

AK202877

19.2 – 19.8 mm

OIL PAN AND OIL PUMP

ENGINE OVERHAUL

11B-49

OIL PAN AND OIL PUMP

REMOVAL AND INSTALLATION

M1113008100464

AK304531 AB

9.0 ± 3.0 N·m

9.0 ± 1.0 N·m

23 ± 3 N·m

54 ± 5 N·m

44 ± 5 N·m

36 ± 3 N·m

10 ± 2 N·m

17 ± 1 N·m

22 ± 4 N·m

19 ± 3 N·m

23 ± 3 N·m

14 ± 2 N·m

19 ± 3 N·m

Apply engine oil to
all moving parts
before installation.

39 ± 5 N·m

Removal steps

1. Drain plug

<< 2. Drain plug gasket

3. Oil level sensor

<< 4. Oil filter

>> >>

<< 5. Oil pan

6. Oil screen
7. Gasket
8. Baffle plate

>> >>

<< 9. Oil pressure switch

10.Oil cooler by-pass valve
11.Relief plug
12.Gasket
13.Relief spring
14.Relief plunger
15.Oil filter bracket
16.Gasket

>> >>

17.Plug

18.O-ring

>> >>

19.Flange bolt

<< 20.Front case

21.Gasket
22.Oil pump cover

<< 23.Oil pump driven gear

<< 24.Oil pump drive gear

<< 25.Crankshaft front oil seal

<< 26.Counterbalancer shaft oil seal

<< 27.Oil pump oil seal

28.Counterbalancer shaft, right
29.Counterbalancer shaft, left

>> >>

<< 30.Counterbalancer shaft front bearing

>> >>

<< 31.Counterbalancer shaft rear bearing,

right

>> >>

<< 32.Counterbalancer shaft rear bearing,

left

Removal steps (Continued)

OIL PAN AND OIL PUMP

ENGINE OVERHAUL

11B-50

REMOVAL SERVICE POINTS
<<A>> OIL PAN REMOVAL

1. Remove the oil pan bolts.

2. Insert the special tool Oil pen remover

(MD998727) into the joint between the cylinder
block and oil pan by tapping the tool with a
hammer.

3. Remove the oil pan by tapping an edge of the

special tool with a hammer to move it sideways.

<<B>> OIL PRESSURE SWITCH
REMOVAL

Using the special tool Oil pressure switch socket
wrench (MD998012) to removal the oil pressure
switch

<<C>> PLUG REMOVAL

Fit the teeth of the special tool in notches of the plug
as shown in the drawing and support the tool with the
special tool to loosen the plug.

• Plug wrench (MD998162)

• Plug wrench retainer (MD998783)

<<D>> FLANGE BOLT REMOVAL

1. Remove the plug on the left side of the cylinder

block. Insert a cross point screwdriver (shank
diameter 8 mm) into the plug hole more than 60
mm to prevent the left counterbalancer shaft from
rotating.

2. Loosen and remove the flange bolt.

<<E>> COUNTERBALANCER SHAFT
FRONT BEARING REMOVAL

AK202574

MD998727

AK300617AC

MD998012

AK202585

MD998162

MD998783

AK202752

Crosspoint
screwdriver

Plug

AK304384

AK202633

Front
bearing

MD998371

Content .. 87 88 89 90 ..