MAN Industrial Diesel Engine D2876 LE103 Service Repair Manual

Foreword
1
This Repair Manual is designed to facilitate proper repair of the engines listed here.
The pictures and associated descriptions show typical work that may not always be applicable to the
engine in hand, which nevertheless does not mean that they are not correct.
In such cases, the repair work is to be planned and carried out in a similar way.
It is compulsory that the engine be removed before performing any of the work described in this Repair
Manual.
The expert knowledge necessary for handling diesel engines was taken for granted when this publication
was compiled.
Note:
Only use fuel, coolants and lubricants in accordance with MAN regulations, otherwise the manu-
facturer’s liability for defects will not apply!
For basic information on the fuels see the publication “Fuels, Lubricants and Coolants for MAN
Diesel Engines”.
You can find the approved products on the Internet at:
−http://www.man-mn.com/ " Products & Solutions " E-Business−
Any repair of components such as injection pump, alternator etc. ought to be left to our or the
manufacturer’s service department.
Best regards
MAN Nutzfahrzeuge Aktiengesellschaft
Nuremberg Plant
Since our products are in continuous development, we reserve the right to make technical modifications.
© 2004 MAN Nutzfahrzeuge Aktiengesellschaft
Reprinting, copying or translation, even of extracts, is not allowed without written permission from MAN.
All rights under the copyright law are strictly reserved by MAN.
MTDB Technical status: 05.2004 51.99598−8068

Instruction
2
Important instructions concerning technical safety and personal protection are, as shown below, especially
highlighted.
Danger:
This refers to working and operating procedures which must be complied with in order to rule out
the risk to persons.
Caution:
This refers to working and operating procedures which must be complied with in order to prevent
damage to or destruction of material.
Note:
Explanatory descriptions which help in understanding the relevant work or operating procedure to
be carried out.
Fitting flat seals / gaskets
Gaskets are frequently used with sealants or adhesives as an aid to assembly or to achieve a better seal.
Above all when parts with different levels of thermal expansion (e.g. aluminium and cast iron) are bonded,
this can mean that the gasket is shifted during operation by the so-called stitching or sewing machine effect
and leaks occur.
Example: The cap of the front crankshaft seal. If a sealing agent or an adhesive is used here the flat seal
will move inwards in the course of time as a result of the different expansion rates of the materials. Oil will
be lost, for which the shaft seal may be thought to be responsible.
Perfect assembly of gaskets can only be achieved if the following instructions are adhered to:
D Use only genuine MAN seals / gaskets.
D The sealing faces must be undamaged and clean.
D Do not use any sealing agent or adhesive − as an aid to fitting the seals a little grease can be used if
necessary so that the seal will stick to the part to be fitted.
D Tighten bolts evenly to the specified torque.
Assembly of round sealing rings
D Use only genuine MAN round sealing rings.
D The sealing faces must be undamaged and clean.
D Always wet round sealing rings with engine oil before fitting them.

Contents
3
Engine type classification 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety instructions 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting Table 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Notes on Engine Overhaul 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Commissioning after engine overhaul 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine views D 2876 LE 103 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Lubrication System Diagram 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel System Diagram 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling System Diagram 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Timing Arrangement Diagram 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel system
Checking and setting start of fuel delivery 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing injection pump 26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing injection nozzles 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking injection nozzles 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel prefilter 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing fuel filter cartridge, venting fuel filter 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel filter heating 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling system
Draining and adding coolant 44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing thermostats 45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing coolant pump 46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repairing coolant pump 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing coolant pump − New front end 50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repairing coolant pump − New front end 53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning cooling system 56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lubrication
Changing oil filter 58. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing oil cooler 60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing oil pan 61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remove / install crankcase yoke 63. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing / repairing oil pump 64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing oil spray nozzle 67. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flywheel / crankshaft seal
Removing and installing vibration damper, replacing front crankshaft seal 68. . . . . . . . . . . . . . . . . . . . .
Removing and installing flywheel, replacing starter ring gear 71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing crankshaft seal (flywheel end) 73. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing bearing race 74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft seals 75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Intake / exhaust system
Removing and installing intake manifolds 76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing exhaust manifold 77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Turbocharger, troubleshooting 79. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking boost pressure 81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing turbocharger 82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Measuring axial / radial clearance of turbocharger shaft 84. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wastegate 85. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder head
Removing and Installing Cylinder Head 86. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting valve clearance 92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Contents
4
Cylinder head
Disassembling and assembling rocker arm mechanism 94. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing valves 98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing valve guides 104. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing valve seat insert 105. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reworking valve seat 107. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Refacing valves 110. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking compression 111. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve timing
Removing and installing timing case 112. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing camshaft 113. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and fitting camshaft bearing bushes 115. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking Valve Timing 124. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankgear, pistons
Removing and installing crankshaft 125. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing pistons with conrods 128. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing pistons on conrod, checking − replacing conrod 131. . . . . . . . . . . . . . . . . . . . . .
Removing and installing / replacing piston rings 133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing cylinder liners 135. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Measuring Piston Protrusion 140. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Attachments
V-belts 141. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ribbed V-belts 143. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and Installing Fan 144. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fan bearing 145. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and Installing Starter Motor 149. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and Installing Air Compressor 150. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Data
Specifications 152. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankcase 153. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder liner 153. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft 154. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flywheel and starter ring gear D 2876 LE 103 156. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flywheel and starter ring gear D 2876 LE 101 / 104 157. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flywheel and starter ring gear D 2876 LE 105 158. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conrods 159. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piston D 2876 LE 101 / 103 / 104 160. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piston D 2876 LE 105 160. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder head 162. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve gear 164. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine lubrication 167. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling system 168. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Turbocharger 169. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel system 170. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starter motor 171. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Alternator 171. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque guide values 173. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special tools 181. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Index 193. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Engine type classification
5
All the engines dealt with here are related in terms of their design and make up a family.
The type classification, which is made up of a series of letters and numbers, reveals some of the features
of the engine in question provided the reader is familiar with the underlying nomenclature.
The system is explained below using the model type D 2876 LE 101 as an example:
D The “D” at the start of the type classification stands for “diesel”.
28 The numbers “28” indicates that the power plant in question has a bore of 128 mm.
7 The “7” indicates a stroke of 166 mm.
6 The “6” indicates a cylinder number of 6. If this position is occupied by a 0, the engine in question
has 10 cylinders.
L This letter indicates “charge air cooling”.
E The “E” indicates a “stationary engine” and are to be distinguished from MAN vehicle engines.
101/2.. This is an internal works development number.

Safety instructions
6
General information
This brief overview summarises important instructions and is structured into areas of main concern in order
to impart the knowledge necessary to prevent accidents involving injury to persons, damage to the engine
or other property and harm to the environment. Additional notes are included in the operator’s manual for
the engine.
Important:
If despite all safety precautions an accident occurs as a result of contact with caustic acids, penetration of
fuel into the skin, scalding with hot oil, anti-freeze splashes into the eyes etc, consult a doctor
immediatel.
1. Instructions for preventing accidents with injury to persons
Checks, setting jobs and repair work must be carried out by authorised skilled personnel only.
D When carrying out maintenance and repair work, ensure that the engine cannot be
accidentally started from the bridge by unauthorised persons.
D The engine must be started and operated by authorised personnel only.
D When the engine is running, do not get too close to revolving components.
Wear tight-fitting working clothes.
D Do not touch hot engine with bare hands: risk of burning yourself.
ËËËË
D Keep engine vicinity, ladder and steps free of oil and grease. Accidents resulting from
slipping may have serious consequences.
D Work only with tools that are in good condition. Worn spanners slip: risk of injuries.
D Persons must not stand under an engine suspended from a crane hook.
Keep lifting gear in good order.
D Open coolant circuit only after the engine has cooled down. If opening the coolant
circuit while the engine is hot is unavoidable, observe the instructions in the chapter
“Maintenance and care” in the Operator’s Manual.
D Neither retighten nor open pressurised pipelines and hoses (lube oil circuit, coolant
circuit and downstream hydraulic oil circuit if fitted): risk of injuries resulting from
emerging fluids.
D When checking the injection nozzles, do not hold your hands in the fuel jet.
Do not inhale fuel mist.

Safety instructions
7
D When working on the electrical system, unplug earth cable from battery first and
reconnect it last to avoid short-circuits.
D Observe the manufacturer’s instructions for handling batteries.
Caution:
Battery acid is toxic and caustic. Battery gases are explosive.
D When carrying out welding work, observe the “Information sheets for welders”.
2. Instructions for preventing damage to the engine and premature wear
D Prior to repairing the engine, clean it thoroughly. Ensure that dirt, sand or foreign matter will
not get into the engine during repair work.
D In the event of operational faults immediately identy the cause and rectify to prevent more serious
damage.
D Always use genuine MAN parts only. Installation of “equally” good parts from other suppliers may cause
severe damage for which the workshop carrying out the work is responsible.
D Never operate the engine while it is dry, i.e. without lubricant or coolant.
Use a suitable label to mark engines not ready for operation.
D Only use operating materials (fuel, engine oil, antifreeze and anticorrosion agents) approved by MAN.
Ensure that everything is kept clean. Diesel fuel must be free of water.
D Do not fill up with engine oil above the max. notch on the dipstick. Do not exceed the engine’s
maximum permissible operating inclination.
Non-compliance with these instructions may cause severe engine damage.
D Control and monitoring devices (charge check, oil pressure, coolant temperature) must work faultlessly.
D Observe the instructions for operating the alternator; see chapter “Maintenance and care” in the
Operator’s Manual.

Safety instructions
8
3. Instructions for preventing environmental damage
Engine oil and filter cartridges and elements, fuel / fuel filters
D Take old oil to an old oil disposal point only.
D Ensure without fail that oil and Diesel fuel will not get into the sewerage system or the ground.
Caution:
Danger of contaminating potable water!
D Treat filter elements and cartridges as special waste.
Coolant
D Treat undiluted anticorrosion and / or antifreeze agents as special waste.
D The regulations of the relevant local authorities are to be observed for the disposal of spent coolants.
4. Instructions for handling used engine oil *
Prolonged or repeated contact of any kind of engine oil with the skin causes the skin to degrease, which
may result in dryness, irritation or inflammation. Old engine oil also contains hazardous substances which
in animal experiments have caused skin cancer. Handling old engine oil does not pose any health hazard if
the basic safety and hygiene related regulations are observed.
Health and safety regulations:
D Avoid prolonged, excessive or repeated contact of old engine oil with the skin.
D Use a suitable skin protection agent or wear protective gloves.
D Clean the skin that has been in contact with engine oil.
− Wash yourself thoroughly with soap and water. A nailbrush is an effective aid.
− Special hand cleaning agents facilitate cleaning soiled hands.
− Do not use petrol, Diesel fuel, gas oil, fluxes or solvents as cleaning agents.
D After washing apply moisturising handcream to your skin.
D Change oil-soaked clothes and shoes.
D Do not put any oil-soaked cloths into pockets.
Pay meticulous attention to the proper disposal of old engine oil.
− Old oil is a water hazard −
Therefore, do not pour any old oil into the ground, the drains or the sewerage system. Any violation of this
rule is punishable.
Collect and dispose of old engine oil properly. For information concerning collection points, contact seller,
supplier or the local authorities.
∗ Based on the “Information sheed for handling used engine oil”
(Notes on how to handle old engine oil).

Troubleshooting Table
9
Operating faults and possible causes
We recommend
A repair is only complete when both the damage that occurred and the possible causes have been
eliminated. Finding out the cause of damage is often more difficult than repairing the damage that occurred.
We therefore recommend that you obtain a precise description of the operating fault before “removing and
dismantling” components. Then use a process of elimination (questions) to pinpoint the probable causes
and investigate and eliminate these successively on the basis of the table and your own experience. This
helps to reduce repairs to the required scale and to counteract claims regarding “overeager” replacement of
parts and complaints about expensive work and down time.
Note:
The following list is conceived as an aid to memory for experts so that no causes of damage are
overlooked when dealing with faults. The precondition for this, however, is that the experts are familiar with
the Repair Manual for the engine as well as the accompanying Operating Instructions and the publication
“Fuels, Lubricants and Coolants for MAN Diesel Engines”.

Troubleshooting table
10
x = Probable
o = Possible
Note:
The troubleshooting table is applicable to engines with EDC MS 5 / 5.32.
Not all the points mentioned below are applicable to engines with EDC MS 6.1 (EDC-specific).
1. EDC self-diagnosis or flash code output
2. Starter motor turns over engine slowly or not at all
3. Starter motor turns, engine fails to start, engine fails to start / difficult to start when cold
4. Engine stalls (dies) during operation, no longer starts (starter motor turns), engine fails to start / difficult to start when hot
5. Sudden, temporary engine shutdown, engine does not reach full revs
6. Engine runs at idle speed only, no throttle response
7. Engine runs at increased idle speed only, no throttle response
8. Rated engine speed significantly reduced (even at no load)
9. Reduced power output in all ranges
10. Irregular engine operation, loss of traction
11. Unstable idle speed, engine surges, misfiring, engine knocking
12. Engine judder
13. Unusual combustion noises
14. Excessive smoke emission: white smoke/blue smoke
15. Excessive smoke emission: black smoke
16. Engine temperature too high (coolant loss)
17. Intermediate speed regulation cannot be activated / does not cut out, engine turns over
excessively
18. Fuel consumption too high
19. Lube oil pressure too low
20. Lube oil pressure too high
21. Lube oil consumption too high
22. Engine too “loud” / mechanical noises
Possible causes
x x Battery flat, battery lead connections loose or corroded, break in power circuit
x Crank gear blocked
x x Starter solenoid switch sticks (clicks) / damaged, cable connection loose or da-
maged
x x Starter motor / starter interlock relay defective (carbon brushes worked loose /
worn, winding damaged, short to ground)
x x x x Engine oil viscosity unsuitable, not suitable for ambient temperature, lube oil qua-
lity does not comply with specifications
x x x Oil level in oil pan too high
x x Oil level in pan too low, oil in oil pan too thin (mixed with condensate or fuel)
x Engine temperature too high
x Oil filter clogged
x x Oil pressure gauge defective
x Safety valve in oil circuit defective (does not close, spring fatigued or broken)
x x Excessive bearing wear
x Oil pump gears heavily worn
x Timing gears worn, tooth flank backlash too great
x x x Engine cold
x Lube oil entering combustion chamber (piston rings worn, piston rings broken) −
valve stem guide worn − overpressure in crankcase (crankcase breather clog-
ged)
x Safety valve in oil circuit defective (does not open), oil lines / oil galleries clogged
x Leaks in lube oil circuit, particularly at turbocharger and oil cooler
x o x Piston rings heavily worn, broken
x x Piston pins or crankshaft bearings loose
o x Valve stems heavily worn, bent
x x x Valve clearance not correct
x x Valves jammed
x x x x Compression deficient, or more than 3−4 bar pressure difference between indivi-
dual cylinders
x x x Valve seats leaking

11
x = Probable
o = Possible
12. Engine judder
excessively
Possible causes
o x x Increased power input due to defective secondary loads / consumers such as
hydraulic pumps, fan etc., power take-off engaged
x x x x x Air cleaner fouled or clogged, charge air system leaking, air intake / exhaust lines
clogged / leaking
x x x x x x x x x Low−pressure fuel system: fuel tank, prefilter, water separator faulty / clogged /
exposed to mould / fungus, fuel unsuitable / heavily contaminated (mixed with
paraffin)
x x x x x x x x Low-pressure fuel system: fuel lines leaking, broken, clogged
x x x x x x x Low-pressure fuel system: air in system (turn on ignition when venting)
x x x x x x x x x Low-pressure fuel system: delivery pump, overflow valve, main filter
x x x x x o x x High-pressure fuel system: nozzles defective / clogged / leaking / coked
x x x x o High-pressure fuel system: pressure lines − constriction, cavitation, leaking
x x o x x x x o High-pressure fuel system: injection pump worn / incorrectly set
o x o o High-pressure fuel system: injection pump constant-pressure control valve / re-
turn flow restrictor defective
x x x o x Safety relay defective, activation faulty
o o o x o x x x Injection pump-engine allocation: start of delivery incorrect (basic installation),
start of delivery incorrectly set
x x x x o x o Injection pump controller: stiff movement - delivery controller (control deviation)
x x x x o Control rod position transducer in controller: connecting leads, open circuit, short
circuit
o o o Control rod position transducer in controller: incorrectly set
x x o Control rod position transducer in controller: capacitance reserve of wiring har-
ness too low (e.g. water penetrated wiring harness)
x o x o o Injection pump: delivery incorrectly set / uniform delivery, lower idle speed set too
low
x o x x x Delivery control solenoid in controller: connecting leads, open circuit, short circuit
x x o o o CAN control failure / defective: connecting leads, short circuit, open circuit
x EDC rpm sensor defective, implausible with auxiliary rpm sensor, lead defective
x o EDC rpm sensor, polarity reversed
x EDC auxiliary rpm sensor defective, implausible with rpm sensor, lead defective
x x x x o o o o EDC detects incorrect engine speed (interference signal on rpm sensor lead)
x x x x o Both rpm sensors defective, lead defective
x x x EDC boost pressure sensor: defective, incorrect, implausible with atmospheric
pressure sensor, lead defective
x x o x Exhaust turbocharger leaking or defective
x Turbine and compressor wheels in turbocharger dirty (irregular running, out-of−
balance)

12
x = Probable
o = Possible
12. Engine judder
excessively
Possible causes
x x Intercooler leaking, defective
x x Flame starting system defective
x o x o x EDC coolant temperature sensor: defective, lead defective
x x o EDC charge air temperature sensor: defective, lead defective
o x x Radiator fouled or failure of cooling system (temperatures too high)
x x Coolant level too low, air in coolant circuit
x V−belt for water pump drive not tensioned correctly
x x Incorrect V-belt tension
x Water pump leaking, defective / thermostat defective, does not open
x Coolant lines leaking, clogged or twisted
x Coolant entering combustion chamber (cylinder head / gasket leaking)
x o Resistor bank EDC control unit pin 51
x x x o o Power supply to control unit interrupted or battery voltage too low
x x o o Lead term. 15 to EDC control unit (pin 47) interrupted / loose contact
x Lead defective: pin 23 or 41
x o o o EDC control unit defective (internal fault)
x o x x o o o x Incorrect EDC control unit (check MAN part number)
x x o Incorrect intermediate speed activated
x EOL programming terminated / power interrupts
x Afterrunning not completed (e.g. shutdown via EMERGENCY STOP)
x EOL programming: incorrect configuration
x Engine bearings worn

General Notes on Engine Overhaul
13
A variety of very different factors has a bearing on the life expectancy of an engine. It is therefore not
possible to specify certain fixed numbers of operating hours for general overhauls.
Regular intermediate examinations and overhauls which are performed in many cases on large engines
(e.g. built by MAN Augsburg) are generally not required on MAN diesel engines built in Nuremberg.
In our view, it is not necessary to open up an engine or perform a general overhaul as long as the engine
has good compression values and the following operating values have not changed significantly in relation
to the values measured on commissioning the engine:
D Boost pressure
D Exhaust temperature
D Coolant and lube oil temperatures
D Oil pressure and oil consumption
D Smoke emissions
The following criteria have a major influence on the life expectancy of an engine:
D Correct power output setting according to the type of application
D Proper installation in accordance with the installation instructions
D Inspection and acceptance of the installation by authorised personnel
D Regular maintenance in accordance with the maintenance schedule in the Service
Booklet
D Choice and quality of lube oil, fuel and coolant in accordance with the publication
“Fuels, Lubricants and Coolants for MAN Diesel Engines”

Commissioning after engine overhaul
14
Pressurisation
It is extremely important for internal combustion engines (following the completion of repair work, i.e. in
their dry state) to be pressurised with lube oil before being recommissioned. This procedure can also be
used for ascertaining damage and its causes.
If engines are not pressurised, the risk of premature damage to bearing surfaces is very high because it
takes a relatively long period of time for the lube oil drawn in from the oil pan via the oil pump to reach the
individual bearings.
Such incipient damage need not necessarily lead to immediate bearing failure, but may impair the proper
functioning of the bearings and reduce their service lives.
Schematic diagram of the flow of oil in non-pressurised engines (source: MIBA)

Commissioning after engine overhaul
15
Pressurising an engine affords the following advantages:
D All engine parts are lubricated before engine startup; a lubricating film can be built up inside the bea-
rings as early as after the first few rotations of the crankshaft, thereby preventing damage to the bearing
races.
D Any loss of oil, be it the result of excessively large bearing play or leaks from the crankcase or from
crankcase bores which may not be plugged, can be detected immediately. For this purpose, mount the
engine on an assembly dolly, remove the oil pan and install a suitable oil collector under the crankcase
in such a way that the bearings are visible.
Performance of pressurisation:
At least 30% of the total oil quantity is forced from the pressurisation container into the engine oil circuit.
The operating pressure serves as the yardstick for the pressure to be forced in and must not be exceeded.
The pressurisation container is connected up to the engine oil circuit at the oil filter head (screw plug,
arrowed).

Engine Lubrication System Diagram
18
1
1 2 3 4
5
10
9
6
7
8
À Suction line Å Bypass valve
Á Distributor pipe Æ Oil filter
Â Oil spray nozzle Ç Turbocharger
Ã Oil pump È Oil cooler
Ä Pressure relief valve É Injection pump

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