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 372 of 1463
1B3-70 OM600 ENGINE MECHANICAL
15. Install the guide pulley (22) and fit the closing cover (20).
16. Replace the gasket (3) and install the cylinder head cover
(2).
17. Install the cooling fan belt pulley and fan clutch.
18. Install the belt tensioning device and then install the belt.
19. Install the cooling fan.
20. Fill the engine oil and check oil leaks by running the engine.
Tightening Torque 23 Nm
Tightening Torque 10 Nm
Page 393 of 1463
OM600 ENGINE MECHANICAL 1B3-91
Notice
If the max. length of bolts(L) exceed 63.8mm, replace them.
19. Coat the new crankshaft with engine oil and place it on the
crankcase.
20. Install the crankshaft bearing caps according to marking
and tighten the bolts.
Tightening Torque 55 Nm + 90°
Notice
Install from No. 1 cap.
22. Rotate the crankshaft with hand and check whether it
rotates smoothly.
23. Measure crankshaft bearing axial clearance.
Clearance 0.100 - 0.245mm
Notice
If the clearance is out of standard, adjust the axial clearance
of crankshaft bearing by replacing the thrust washers.
Dial Gauge 001 589 53 21 00
Dial Gauge Holder 363 589 02 21 00
Notice
The same thickness of thrust washers should be installed
on both sides of the thrust bearing.
Page 394 of 1463

1B3-92 OM600 ENGINE MECHANICAL
28. Remove the connecting rod bearing cap.
29. Install the piston.
30. Rotate the crankshaft by hand and check whether it rotates
smoothly.
31. If the bearings are damaged,
- replace the oil presser relief valve.
- clean the oil pump and oil filter housing carefully and
replace the hose if necessary.
Notice
After assembling the engine, check the camshaft timing,
adjust the start of fuel injection and check the TDC sensor
bracket setting.
32. Fill oil and run the engine and then check the oil pressure
and oil level.
Notice
Install the original oil filter element and then change the
engine oil and oil filter element after 1,000 - 1,500km. 27. Measure the radial clearance (L) of the connecting rod
bearing.
Example)Measured value ‘J’ = 47.700mm
Measured value ‘K’ = 47.653mm
Clearance ‘L’ = 0.047mm
Radial Clearance ‘L’ 0.026 - 0.068mm
Notice
If the clearance is out of standard, adjust the radial
clearance of connecting rod bearing by replacing the
connecting rod bearing shells. 26. Measure connecting rod bearing journal diameter (K).
Notice
Refer to measurement of the crankshaft bearing journal
diameter.
24. Insert the new connecting rod bearing shells into the
connecting rod and connecting rod bearing cap and tighten
the 12-sided stretch bolts (11).
25. Measure inner diameter of connecting rod bearing.
Tightening Torque 40 Nm + 90°
Page 395 of 1463
OM600 ENGINE MECHANICAL 1B3-93
FLYWHEEL
Preceding Work : Removal of the transmission
Removal of the clutch
1 Oil Pan
2 Straight Pin
3 Flywheel4 12-Sided Stretch Bolt............Check, 45Nm + 90°
5 Drive Plate (Automatic Transmission)
6 Flywheel (Automatic Transmission)
Page 404 of 1463

1B3-102 OM600 ENGINE MECHANICAL
Checking
Notice
The noise which continues short time during short travel
(frequent starting of the engine) or engine starting after a
long time storage is normal operating conditions. So, it does
not need to be repaired. Determine the malfunctions in valve
clearance compensation device with noise through following
tests. If defective, replace as respectively.
1. Run the engine at more than 3000rpm for approx. 4 minutes.
2. Stop the engine. After 5minutes, check the engine oil level
and adjust if necessary.
3. Remove the cylinder head cover.
4. Check the valve tappets at TDC position of each cylinders.
5. Using a drift, lightly press the valve tappet and measure
clearance between the cam and valve tappet.
Notice
If the clearance exceeds 0.4mm, replace the valve tappet.
6. If a valve tappet moves down too far in comparison to the
others, replace the valve tappet.
7. Rotate the engine and check the remaining valve tappets.
Notice
lUnnecessary rotation of the engine will damage the valve
tappets.
lDo not rotate the engine by using the camshaft sprocket
bolt or to the opposite direction of the engine rotation.
Page 406 of 1463
1B3-104 OM600 ENGINE MECHANICAL
Replacement Procedure
1. Pull out the valve tappet (1).
Magnetic Bar 102 589 03 40 00
2. Remove the plug (5) and blow compressed air into the oil
gallery (3). At this time, check that the outlet bores(arrow)
at the seat of the valve tappet are clear.
3. Replace the seal (4) and tighten the plug (5).
4. Insert the new valve tappet.
Notice
Coat the valve tappet with oil.
Page 413 of 1463
OM600 ENGINE MECHANICAL 1B3-111
6. Remove the spring retainer(3) and spring (4).
7. Check the valve spring and replace if necessary.
8. Insert valve spring (4) with the color coding (arrow) facing
down and insert valve spring Retainer(3).
9. By press the spring retainer(3) with press lever (90), install
the valve cotters with magnetic finger (10).
Press Lever 667 589 00 31 00
Magnetic Finger 116 589 06 63 00
10. Remove the supporting bar.
11. Remove the holding wheel (7) from the timing chain (5).
Holding Wheel 603 589 01 40 00
13. Coat the valve tappet with oil and install it.
Magnetic Bar 102 589 03 40 00