Mitsubishi 380. Manual - part 451

CYLINDER HEAD AND VALVES

ENGINE OVERHAUL <3.8L ENGINE>

11B-30

Required Special Tools:

• MB991999: Valve Stem Seal Installer

• MD998051: Cylinder Head Bolt Wrench

• MD998735: Valve Spring Compressor

• MD998772: Valve Spring Compressor

REMOVAL SERVICE POINTS

.

<<A>> CYLINDER HEAD BOLT REMOVAL

Use special tool MD998051 to loosen the cylinder head bolt.

.

<<B>> >>C<<

9.

RETAINER LOCK

10. VALVE SPRING RETAINER

>>B<<

11. VALVE SPRING
12. EXHAUST VALVE

>>A<<

13. VALVE STEM SEAL
14. VALVE SPRING SEAT

>>A<<

15. VALVE STEM SEAL
16. VALVE SPRING SEAT
17. INLET VALVE GUIDE
18. SNAP RING
19. EXHAUST VALVE GUIDE
20. INLET VALVE SEAT
21. EXHAUST VALVE SEAT
22. CYLINDER HEAD

REMOVAL STEPS (Continued)

AK302682AB

MD998051

CYLINDER HEAD AND VALVES

ENGINE OVERHAUL <3.8L ENGINE>

11B-31

<<B>> RETAINER LOCK REMOVAL

1. Using special tool MD998735 or MD998772, compress the 

spring.

2. Remove the retainer locks.

NOTE: Tag removed valves, springs and other components, 
noting their cylinder numbers and locations to facilitate reas-
sembly. Store these components safely.

AK100166

MD998735

AB

AKX00617

MD998772

AB

CYLINDER HEAD AND VALVES

ENGINE OVERHAUL <3.8L ENGINE>

11B-32

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

CAUTION

Always use the special tool to install the valve stem seal. 
Improperly installed valve stem seals may leak oil.
2. Using special tool MB991999, 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.

.

AK303630

EXHAUST

RUBBER COLOR:

GRAY

RUBBER COLOR:

GRAY GREEN

INTAKE

AB

AKX00618AC

MB991999

AKX00718

SPRING SEAT

SPRING 

RETAINER

IDENTIFI-

CATION 

COLOR

STEM SEAL

AB

CYLINDER HEAD AND VALVES

ENGINE OVERHAUL <3.8L ENGINE>

11B-33

>>C<< RETAINER LOCK INSTALLATION

Using special tool MD998735 or MD998772, compress the 
valve spring and insert the retainer lock into position.

NOTE: The valve spring, if excessively compressed, causes 
the bottom end of retainer to damage the stem seal.

.

>>D<< CYLINDER HEAD BOLT INSTALLATION

CAUTION

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

steps.

Tightening torque: 108 

± 5 N⋅m (80 ± 4 ft-lb)

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

specified torque in step1.

AK100166

MD998735

AB

AKX00617

MD998772

AB

AKX01452AB

FRONT

MD998051

HEAD

BOLT

WASHER

RIGHT

BANK

LEFT

BANK