Page 206 of 1463
M161 ENGINE MECHANICAL 1B2-17
CRANKCASE VENTILATION SYSTEM
Operation at Idling and Mid-Load
1 HFM Sensor
2 Cylinder Head Cover
3 Oil Spearation Chamber (Full-Load or Over
Mid-Load)
4 Intake Air Duct (Cross Pipe)
5 Vent Line (Full-Load or Over Mid-Load)
6 Throttle Valve
7 Restrictor, Diameter 1.1mm (Mid-Load at Idling)
8 Intake Manifold
9 Vent Line (Mid-Load at Idling)
10 Air Conditioner Bracket11 Oil Separation Chamber (Mid-Load at Idling)
12 Crank Chamber
13 Oil Return Pipe
14 Oil Pan
15 Timing Gear Case Cover
16 Crankcase
17 Chain Housing
A Fresh Air
C Blow-by Gas
D Vent Connection
Page 207 of 1463
1B2-18 M161 ENGINE MECHANICAL
Operation at Idling and Mid-Load
lThe throttle valve(6) is closed or very partially opened, and
the vacuum pressure in intake manifold is high.
The blow-by gas and the fresh air that is additionally supplied
through the vent connection(D) in the crankcase in partial
load gets supplied to the combustion chamber from the crank
chamber(12) through the oil separation chamber(11), air-
conditioner bracket(10), vent line(9), and restrictor(7)
mounted to the cylinder head.
The circulated engine oil returns to the oil pan through the
oil return pipe(13) at the bottom of oil separation
chamber(11).
The fresh air gets supplied to the crank chamber(12) through
the HFM sensor(1), intake air duct(4), vent line(5), oil
separation chamber(3), chain housing(17), and the timing
gear case cover(15).
The additional supply of the fresh air is needed to prevent
from forming the residues of the engine oil.
Page 208 of 1463
M161 ENGINE MECHANICAL 1B2-19
Operation When Full-Load at Partial Load
1 HFM Sensor
2 Cylinder Head Cover
3 Oil Spearation Chamber (Full-Load or Over
Mid-Load)
4 Intake Air Duct (Cross Pipe)
5 Vent Line (Full-Load or Over Mid-Load)
6 Throttle Valve
7 Restrictor, Diameter 1.1mm (Mid-Load at Idling)
8 Intake Manifold
9 Vent Line (Mid-Load at Idling)
10 Air Conditioner Bracket11 Oil Separation Chamber (Mid-Load at Idling)
12 Crank Chamber
13 Oil Return Pipe
14 Oil Pan
15 Timing Gear Case Cover
16 Crankcase
17 Chain Housing
A Fresh Air
C Blow-by Gas
D Vent Connection
Page 303 of 1463

SECTION 1B3
OM600 ENGINE MECHANICAL
CAUTION: Disconnect the negative battery cable before removing or installing any electrical unit or when a
tool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable
will help prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unless otherwise
noted.
Specifications . . . . . . . . . . . . . . . . . . . . . . . 1B3-2
Fastener Tightening Specifications . . . . . . . . 1B3-2
Special Tools . . . . . . . . . . . . . . . . . . . . . . . 1B3-4
Special Tools Table . . . . . . . . . . . . . . . . . . . . 1B3-4
Maintenance and Repair . . . . . . . . . . . . . 1B3-12
On-Vehicle Service . . . . . . . . . . . . . . . . . . . . 1B3-12
Engine Assembly . . . . . . . . . . . . . . . . . . . . 1B3-12
Poly V-Belt . . . . . . . . . . . . . . . . . . . . . . . . . 1B3-21
Tensioning Device . . . . . . . . . . . . . . . . . . . . 1B3-23
Poly V-Belt Alignment & Inspection . . . . . . . 1B3-26
Prechamber . . . . . . . . . . . . . . . . . . . . . . . . 1B3-29
Milling of Prechamber Sealing Surface . . . . 1B3-32
TDC (TDC Sensor Bracket) Setting . . . . . . 1B3-35
Cylinder Head . . . . . . . . . . . . . . . . . . . . . . . 1B3-37
Timing Case Cover . . . . . . . . . . . . . . . . . . . 1B3-63
Crankshaft End Cover . . . . . . . . . . . . . . . . 1B3-71
Vibration Damper and Hub . . . . . . . . . . . . . 1B3-74
Crankshaft Front Radial Seal . . . . . . . . . . . 1B3-80
Crankshaft Ball Bearing . . . . . . . . . . . . . . . 1B3-82
Crankshaft . . . . . . . . . . . . . . . . . . . . . . . . . 1B3-83
Flywheel . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B3-93
Machining of Flywheel . . . . . . . . . . . . . . . . 1B3-97
Flywheel Ring Gear . . . . . . . . . . . . . . . . . . 1B3-98
Hydraulic Valve Clearance Compensation
Element Check . . . . . . . . . . . . . . . . . . . . 1B3-101
Valve Tappets . . . . . . . . . . . . . . . . . . . . . . 1B3-103
Valve Spring Check . . . . . . . . . . . . . . . . . 1B3-105
Valve Springs (Cylinder Head Removed) . 1B3-106
TABLE OF CONTENTS
Valve Springs (Cylinder Head Installed) . . 1B3-109
Valve Stem Seals . . . . . . . . . . . . . . . . . . . 1B3-112
Check and Replacement of
Valve Guides . . . . . . . . . . . . . . . . . . . . . 1B3-116
Valve Seat Rings . . . . . . . . . . . . . . . . . . . 1B3-122
Check and Machining of Valves . . . . . . . . 1B3-127
Machining of Valve Seat . . . . . . . . . . . . . . 1B3-132
Camshaft Timing Test . . . . . . . . . . . . . . . . 1B3-137
Camshaft . . . . . . . . . . . . . . . . . . . . . . . . . 1B3-139
Chain Tensioner . . . . . . . . . . . . . . . . . . . . 1B3-145
Timing Chain . . . . . . . . . . . . . . . . . . . . . . . 1B3-147
Tensioning Rail . . . . . . . . . . . . . . . . . . . . . 1B3-151
Cylinder Head Guide Rail . . . . . . . . . . . . . 1B3-152
Timing Case Cover Guide Rail . . . . . . . . . 1B3-156
Crankshaft Sprocket . . . . . . . . . . . . . . . . . 1B3-158
Piston . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B3-163
Oil Filter . . . . . . . . . . . . . . . . . . . . . . . . . . 1B3-169
Oil Pan . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B3-171
Oil Spray Nozzle . . . . . . . . . . . . . . . . . . . . 1B3-174
Oil Pump . . . . . . . . . . . . . . . . . . . . . . . . . . 1B3-175
Unit Repair . . . . . . . . . . . . . . . . . . . . . . . 1B3-177
Cylinder Head Pressure Leakage Test . . . 1B3-177
Facing Cylinder Head Mating Surface . . . . 1B3-178
Replacement of Crankcase Core Plug . . . 1B3-180
Facing Crankcase Contacting Surface . . . 1B3-182
Oil Gallery Steel Ball . . . . . . . . . . . . . . . . . 1B3-183
Cylinder Bore Measurement . . . . . . . . . . . 1B3-187
Page 307 of 1463
OM600 ENGINE MECHANICAL 1B3-5
116 589 03 07 00
T Type Socket Wrench
601 589 00 25 00
SPECIAL TOOLS TABLE (Cont’d)
115 589 34 63 00
601 589 00 10 00
Cylinder Head Bolt 102
102 589 12 15 00
(
f ff f
f17) Drift102 589 00 15 00
(
f ff f
f34) Drift
617 589 10 21 00
RI Sensor601 589 05 14 00
Assembly Cage
Page 313 of 1463
OM600 ENGINE MECHANICAL 1B3-11
000 589 14 21 00
Tester
001 589 65 09 00
Serration Wrench116 589 02 34 00
Thread Bolt
SPECIAL TOOLS TABLE (Cont’d)
000 589 00 68 00
Cleaning Set
601 589 05 21 00
Looking Screw617 589 08 21 00
Position Sensor 667 589 04 63 00
Retaining Plate
601 589 00 08 00
Flange
Page 320 of 1463
1B3-18 OM600 ENGINE MECHANICAL
27. Disconnect the preheating time relay sensor plug.
28. Disconnect the coolant temperature sensor plug.
29. Disconnect the accelerator cable from the control linkage.
Installation Notice
Tightening Torque 8 - 18 Nm
30. Loosen the connection of control pressure cable (an arrow)
used in auto transmission.
Page 337 of 1463
OM600 ENGINE MECHANICAL 1B3-35
TDC (TDC SENSOR BRACKET) SETTING
Preceding Work : Removal of No.1 cylinder prechamber
1 Measuring Device
2 Dial Gauge
3 Cylinder Head
4 Piston................................................Set at TDC
Tools Service
001 589 32 21 00 Dial Gauge
601 589 07 21 00 Deqth Gauge
667 589 01 21 00 Fixing Device
Notice
lThe TDC sensor bracket must be adjusted in case of
followings.
lWhen replacing the TDC sensor bracket.
lWhen replacing the crankshaft, the hub or the vibration
damper.
lWhen replacing or installing the timing case cover.
lAfter engine overhauling.
*If the cylinder head is removed, the measuring pin of the
dial gauge can be positioned on the piston crown.
This is done by placing the magnetic dial holder on the
mating surface of the crankcase.