REMOVAL AND INSTALLATION



caution *Remove and assemble the marked parts in each cylinder unit.
Pre-removal operation
  • Engine Room Under Cover Front B and Engine Room Side Cover (RH) Removal (Refer to GROUP 51 - Under Cover ).
  • Engine Oil Draining (Refer to GROUP 12 - On-vehicle Service, Engine Oil Replacement <4B1, 6B3> ).
  • Rocker Cover Assembly Removal (Refer to ).
  • Engine Oil Pan Removal (Refer to ).
  • Valve Timing Chain Removal (Refer to ).

Post-installation operation
  • Valve Timing Chain Installation (Refer to ).
  • Engine Oil Pan Installation (Refer to ).
  • Valve Clearance Check (Refer to ).
  • Rocker Cover Assembly Installation (Refer to ).
  • Engine Oil Refilling (Refer to GROUP 12 - On-vehicle Service, Engine Oil Replacement <4B1, 6B3> ).
  • Engine Room Under Cover Front B and Engine Room Side Cover (RH) Installation (Refer to GROUP 51 - Under Cover ).





Removal steps
<<A>>
>>F<<
1.
Camshaft bearing front cap assembly

>>E<<
2.
Camshaft bearing
<<B>>
>>D<<
3.
Camshaft bearing oil feeding cap (exhaust side)
<<B>>
>>D<<
4.
Camshaft bearing cap (exhaust side)
<<B>>
>>D<<
5.
Camshaft bearing cap (exhaust side)
<<B>>
>>D<<
6.
Camshaft bearing thrust cap (exhaust side)

>>E<<
7.
Camshaft and camshaft sprocket assembly (exhaust side)

>>E<<
8.
Camshaft bearing
<<B>>
>>D<<
9.
Camshaft bearing oil feeding cap (inlet side)
<<B>>
>>D<<
10.
Camshaft bearing cap (inlet side)
<<B>>
>>D<<
11.
Camshaft bearing cap (inlet side)
<<B>>
>>D<<
12.
Camshaft bearing thrust cap (inlet side)


13.
Camshaft and camshaft sprocket assembly (inlet side)


14.
Spark plug
<<C>>
>>C<<
15.
Valve tappet
<<D>>
>>B<<
16.
Valve spring retainer lock


17.
Valve spring retainer


18.
Valve spring
<<E>>
>>A<<
19.
Valve stem seal

REMOVAL SERVICE POINTS



<<A>> CAMSHAFT BEARING FRONT CAP ASSEMBLY REMOVAL


1.Temporarily install the engine oil pan which was removed at the valve timing chain removal (Refer to ).
2.
caution When supporting the engine and transmission assembly with a garage jack, be careful not to deform the engine oil pan.
Place a garage jack against the engine oil pan with a piece of wood in between to support the engine and transmission assembly.


3.Remove special tool engine hanger (MB991928 or MB991895) which was installed for supporting the engine and transmission assembly when the valve timing chain was removed.

4.
caution Be careful not to drop the camshaft bearing.
Loosen the camshaft bearing front cap mounting bolts in the order of number shown in the figure, and remove the camshaft bearing front cap assembly.

<<B>> CAMSHAFT BEARING OIL FEEDING CAP/CAMSHAFT BEARING CAP/CAMSHAFT BEARING THRUST CAP REMOVAL


caution When the camshaft bearing cap mounting bolts are loosened at once, the mounting bolts jump out by the spring force and the threads are damaged. Always loosen the mounting bolts in four or five steps.

Loosen the camshaft bearing cap mounting bolts in the order of number shown in the figure in four or five steps, and remove the camshaft bearing caps.

<<C>> VALVE TAPPET REMOVAL


caution
  • Do not use pliers or other tools to remove the valve tappets. Always remove them by hands.
  • When reusing the removed valve tappet, it has to be installed in the same position as before. Be sure to put a tab that shows the original installation position on the valve tappet when storing it.

Remove all of the valve tappets by hands.

<<D>> VALVE SPRING RETAINER LOCK REMOVAL



1.Screw in special tool retainer holder attachment (MB992090) to special tool valve spring compressor (MD998772), and assemble special tool retainer holder C (MB992089).
2.
caution When removing the valve spring retainer lock, leave the piston of the cylinder in the TDC (Top Dead Centre) position. The valve may fall into the cylinder if the piston is not properly in the TDC position.
Install special tool MD998772 (with special tools MB992090 and MB992089 attached) to the cylinder head and compress the valve spring. Then, remove the valve spring retainer lock.

<<E>> VALVE STEM SEAL REMOVAL



Use special tool valve stem seal pliers (MB992085) to nip the base of the stem seal (where the outside diameter is larger) securely, and remove it by twisting it to the left and right.

INSTALLATION SERVICE POINTS



>>A<< VALVE STEM SEAL INSTALLATION


1.Apply a small amount of engine oil to the valve stem seals.

2.
caution
  • Valve stem seals cannot be reused.
  • Do not damage the wall of the tappet hole when installing the valve stem seal.
  • Special tool valve stem seal installer (MD998737) must be used to install the valve stem seal. Improper installation of the valve stem seal could result in oil leaking past the valve guide.
Use special tool valve stem seal installer (MD998737) to press-fit a new valve stem seal in the valve guide using the valve stem area as a guide.

>>B<< VALVE SPRING RETAINER LOCK INSTALLATION



In the same manner as removal, use special tool valve spring compressor (MD998772) with special tool retainer holder attachment (MB992090) and special tool retainer holder C (MB992089) attached to compress the valve spring, and install the valve spring retainer lock.

>>C<< VALVE TAPPET INSTALLATION


1.Apply a small amount of engine oil to the valve tappets.

2.
caution
  • Do not use pliers or other tools to install the valve tappets. Always install them by hand.
  • Be sure to install the valve tappets in the same position as before.
Install the valve tappet to the cylinder head by hand.

>>D<< CAMSHAFT BEARING THRUST CAP/CAMSHAFT BEARING CAP/CAMSHAFT BEARING OIL FEEDING CAP INSTALLATION



1.Install the camshaft bearing caps to the cylinder head.
note Because the camshaft bearing thrust cap and camshaft bearing cap are the same in shape, check the cap number and additionally its symbol to identify the inlet and exhaust sides for correct installation.
2.Tighten each camshaft bearing cap mounting bolts to the specified torque in the order of number shown in the figure in two or three steps.
Tightening torque: 12 ± 1 N·m

>>E<< CAMSHAFT BEARING/CAMSHAFT AND CAMSHAFT SPROCKET ASSEMBLY (EXHAUST SIDE) INSTALLATION


caution
  • Be careful not to drop the camshaft bearing.
  • When installing the camshaft and camshaft sprocket assembly (exhaust side), be careful not to let the camshaft bearing which is installed to the front cam bearing deviate from its position.


When replacing the camshaft bearing, select a camshaft bearing in relevant size according to the camshaft bearing front cap identification mark in the table below. Identification colour of the camshaft bearing is painted in the position shown in the figure.
Camshaft
Camshaft bearing identification colour
Identification mark
Journal diameter mm
1
40.000 - 40.008
Black
2
40.008 - 40.016
None
3
40.016 - 40.024
Green

>>F<< CAMSHAFT BEARING FRONT CAP ASSEMBLY INSTALLATION



1.
caution When the mounting bolts are tightened with the camshaft bearing front cap tilted, the camshaft bearing front cap is damaged. Install the camshaft bearing front cap properly to the cylinder head and camshaft.
Install the camshaft bearing front cap to the cylinder head, and temporarily tighten the camshaft bearing front cap mounting bolts to the specified torque in the order shown in the figure (1).
Tightening torque: 17 ± 3 N·m
2.Tighten again the camshaft bearing front cap mounting bolts to the specified torque again in the order shown in the figure (2).
Tightening torque: 30 ± 2 N·m


3.Install special tool engine hanger (MB991928 or MB991895) which was installed for supporting the engine and transmission assembly when the valve timing chain was removed (Refer to ).
4.Remove the garage jack which supports the engine and transmission assembly.
5.Remove the engine oil pan installed temporarily.