Repair Manual Guide

Preface
1
This Repair Manual is designed to facilitate competent repair of the engines listed here in.
In addition to this Repair Manual the following publications are available:
D Operating Instructions
D Fuels, Lubricants and Coolants for MAN Diesel Engines
D Spare-parts catalogue
D Service record book with maintenance plan
The pictures and relevant 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 describe in this Repair Ma-
nual.
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’s regulations otherwise the manu-
facturer’s warranty 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 in the internet under:
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 manufac-
turer’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.
© 2006 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: 03.2006 51.99598−8166

Instructions
2
Important instructions which concern technical safety and protection of persons are emphasised as shown
below.
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.
Assembly of pipes
Danger:
No pipes may be bent.
Risk of breakage!
Fitting flat seals / gaskets
Flat seals / gaskets are often inserted with sealing agents or adhesives to make fitting them easier or to
achieve better sealing. Flat seals may slip in operation due to the “sewing -machine” effect, in particular if
they are used between parts with different rates of linear expansion under heat (e.g. aluminium and cast
iron), and leaks may then 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.
Flat seals / gaskets can be fitted properly only if the following points are observed:
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
Fitting 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
Preface 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Instructions 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine type classification 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety regulations 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fault table 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General notes on engine overhaul 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Commissioning after engine overhaul 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine views 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematic diagram of engine lubrication 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematic diagram of cooling system 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematic diagram of fuel system 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematic diagram of engine timing 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel system
Removing and installing high-pressure pump 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing the high-pressure lines 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing the rail 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing the injectors 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel prefilter 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing the Fuel Service Centre, replacing the filter cartridge 36. . . . . . . . . . . . . . . . . .
Cooling system
Draining and filling coolant 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing thermostats 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing expansion tank 42. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing coolant pump 43. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repairing coolant pump 45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning cooling system 50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing heat exchanger 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing pipe cluster for heat exchanger 53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning heat exchanger pipe cluster 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing sea water pump 56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing/installing/stripping seawater pump 57. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing impeller of sea water pump 59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lubrication
Changing oil filter 61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing the oil cooler 62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing, repairing oil pump 64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing oil injection nozzle 68. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flywheel / Crankshaft seal
Removing and fitting vibration damper, replacing front crankshaft gasket 69. . . . . . . . . . . . . . . . . . . . . .
Removing and installing flywheel, replacing starter gear ring 73. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing crankshaft seal (flywheel end) 75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing the bearing race 76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft seals 77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Intake / exhaust system
Removing and installing intake pipes 78. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing exhaust pipe 79. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Turbocharger, troubleshooting 81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing turbocharger 83. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Waste gates 85. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing intercooler 86. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Contents
4
Cylinder head
Removing and installing cylinder head 89. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting the valve clearance 93. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dismantling and assembling the 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 the timing case 114. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing camshaft 116. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing camshaft bearing bushes 118. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the valve timing 127. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankgear, pistons
Removing and installing crankshaft 128. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and installing pistons with conrods 131. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing pistons from conrod and fitting, checking − replacing conrod 134. . . . . . . . . . . . . . . . . . . . . . .
Removing and installing piston rings 136. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing cylinder liners 138. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Measuring piston protrusion 142. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Attachments
Removing and installing starter motor 143. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing and attaching alternator 144. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
V-belts 145. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankcase breather (oil separator) 147. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Data 149. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine − Technical data 150. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankcase 151. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder liner 151. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft 152. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flywheel and starter gear ring 154. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conrod 155. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conrod bearing 155. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pistons 156. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder head 157. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve train 159. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine lubrication 162. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling system 163. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Turbocharger 165. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel system 166. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starter motor 167. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Alternator 167. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque guide values 168. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special tools 173. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Index 187. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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 423 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” means 166 mm stroke
6 The “6” indicates the number of cylinders 6
L This letter stands for “charge-air cooling” (German: Ladeluftkühlung)
E The “E” stands for “fitted engine” (German: Einbaumotor) and is intended to distinguish MAN
vehicle engines
423 This is a factory-internal development number

Safety regulations
6
General notes
Important safety regulations are summarized in this quick-reference overview and arranged by topic to ef-
fectively convey the knowledge necessary to avoid accidents causing injury, damage or environmental haz-
ard. Additional information can be found in the operating instructions of the engine.
Important:
Should an accident occur despite all precautionary measures, particularly one involving contact with corros-
ive acid, penetration of fuel under the skin, scalding by hot oil, antifreeze splashing into the eyes etc. you
must seek medical assistance immediately.
1. Regulations for the prevention of accidents with personal injury
Inspection, adjustment and repair work may only be performed by authorised and skilled person-
nel.
D During installation work, switch off the battery master switch.
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 may only be started and operated by authorised personnel.
D When the engine is running, do not get too close to the rotating parts.
Wear close-fitting working clothes.
D Do not touch hot engine with bare hands: Risk of burns.
ËËËËD Keep area surrounding engine, ladders and stairways free of oil and grease.
Accidents caused by slipping can have serious consequences.
D Only work with tools which are in good condition. Worn spanners / wrenches slip:
Danger of injury.
D Persons must not stand under an engine suspended on a crane hook. Keep lifting gear
in order.
D Open the coolant circuit only when 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 Do not tighten or undo pipes and hoses under pressure (lubricating oil circuit, coolant
circuit and any downstream hydraulic oil circuits). The fluids which flow out can cause
injury.

Safety regulations
7
D When working on the electrical system, first disconnect the earth cable of the battery
and reconnect this last to prevent short circuits.
D Follow the manufacturer’s instructions for handling batteries.
Caution:
Accumulator acid is toxic and caustic. Battery gases are explosive.
D When performing welding work, observe the “Notes for welders”.
2. Regulations designed to prevent damage to 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 If engine operation is disrupted, immediately determine the cause and have it remedied to prevent addi-
tional 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 allow the engine to run dry, i.e. without lubricant or coolant.
Appropriate notices must be attached to engines that are not ready for operation.
D Today modern components of diesel injection consist of high-precision parts which are exposed to ex-
treme stresses. The high-precision technology requires the utmost cleanliness during all work on the
fuel system.
Even a particle of dirt over 0.2 mm can lead to the failure of components.
D Use only MAN-approved service products (fuel, engine oil, anti-freeze and anti-corrosion agent).
Pay attention to cleanliness. Diesel fuel must be free of water.
D Do not fill engine oil beyond the max. notch on the dipstick. Do not exceed the maximum per-
missible tilt of the engine.
Serious damage to the engine may result if these instructions are not adhered to.
D Control and monitoring devices (charge control, oil pressure, coolant temperature) must be in perfect
working order.
D Observe the instructions for operating the alternator; see chapter “Maintenance and care” in the Oper-
ator’s Manual.

Safety regulations
8
3. Regulations for the prevention of environmental damage
Engine oil and filter elements / cartridges, fuel / fuel filter
D Old oil must be passed on for recycling.
D Take strict precautions to ensure that no oil or Diesel fuel gets into the drains or the ground.
Caution:
Risk of contamination of potable water.
D Filter elements are classed as dangerous waste and must be treated as such.
Coolant
D Treat undiluted corrosion protection agents and / or antifreeze as hazardous waste.
D When disposing of used coolant, the regulations issued by the relevant local authorities must be ob-
served.
4. Notes on safety in handling used engine oil *
Prolonged or repeated contact between the skin and any kind of engine oil decreases the skin. Drying, ir-
ritation or inflammation of the skin may therefore occur. Used engine oil also contains hazardous sub-
stances that have caused skin cancer in tests on animals. If the basic principles of work safety and hygiene
are observed, handling used engine oil does not represent a health hazard.
Precautionary measures to protect your health:
D Avoid prolonged or repeated skin contact with used engine oil.
D Protect your skin by means of suitable agents (creams etc.) or wear protective gloves.
D Clean skin which has been in contact with engine oil.
− Wash thoroughly with soap and water. A nail brush provides effective assistance here.
− Special hand cleaning agents make it easier to clean dirty hands.
− Do not use petrol (gasoline), diesel fuel, gas oil or solvents as washing agents.
D After washing apply a fatty skin cream to the skin.
D Change clothing and shoes that are soaked in oil.
D Do no put oily cloths in you pockets.
Ensure that used engine oil is disposed of in the appropriate manner.
− Engine oil is a substance that endangers the water supply −
For this reason do not let engine oil get into the ground, waterways, the drains or the sewers. Violations are
punishable.
Carefully collect and dispose of used engine oil. Information on collection points can be obtained from sales
personnel, the supplier or the local authorities.
∗ Based on “Information sheet for handling used engine oil”.

Safety regulations
9
5. Special instructions when working on the common rail system
Accident protection
D Risk of injury!
Fuel jets can cut through skin.
The atomisation of fuel creates a fire risk.
− When the engine is running never loosen the screw connections on the fuel’s high-
pressure side of the common rail system (injection line from the high-pressure pump
to the rail, on the rail and on the cylinder head to the injector).
− Keep away from the engine when it is running.
D Risk of injury!
When the engine is running the lines are constantly under a fuel pressure of up
to 1600 bar.
− Wait at least a minute until the pressure in the rail has dropped before loosening a
screw connection.
− If necessary check the pressure drop in the rail with MAN-Cats.
D Risk of injury!
− People with pacemaker must keep at least 20 cm away from the running engine.
− Do not touch live parts on the electric connection of the injectors when the engine is
running.

Safety regulations
10
Cleanliness
Today modern components of diesel injection consist of high-precision parts which are exposed to extreme
stresses. The high-precision technology requires the utmost cleanliness during all work on the fuel sys-
tem.
Even a particle of dirt over 0.2 mm can lead to the failure of components.
The measures described as follows are therefore essential before work begins:
Risk of damage from penetration of dirt!
D Before working on the clean side of the fuel system clean the engine and the engine
compartment (high-pressure cleaner). During cleaning the fuel system must be closed.
D Carry out visual inspection for any leakage or damage to the fuel system.
D Do not spray the high-pressure cleaner direct onto the electric components, or alterna-
tively keep them covered.
D Do not carry out any welding or sanding work in the engine compartment during main-
tenance / repair.
D Avoid air movements (any swirling of dust when starting engines).
D The area of the still closed fuel system must be cleaned and dried with the aid of com-
pressed air.
D Remove detached particles of dirt such as paint chippings and insulation material with a
suitable extractor (industrial type vacuum cleaner).
D Cover areas of the engine compartment from which dust particles could be detached
with clean foil.
D Wash your hands and put on clean work clothes before starting the disassembly work.
D Clean tools and working materials before starting to work.

Safety regulations
11
When carrying out the work it is essential to comply with the following measures:
Risk of damage from penetration of dirt!
D When the clean side of the fuel system has been opened it is not permissible to use
compressed air for cleaning.
D During assembly work loose dirt must be removed with the aid of suitable extractors
(industrial type vacuum cleaners).
D Use only fluff-free cleaning cloths on the fuel system.
D Only tools without any damage may be used (cracked chrome coatings).
D When removing and installing components do not use materials such as cloths, card-
board or wood since these could shed particles and fine fibres.
D If any paint chips / flakes off when connections are loosened (from possible over-coat-
ing) these chippings must be carefully removed before finally loosening the screw con-
nection.
D The connection openings of all removed parts on the clean side of the fuel system are
to be closed immediately with suitable caps (see special tools).
D These caps / stoppers must be packed protected from dust prior to use and after being
used once they must be disposed of.
D Following this all the components must be carefully stored in a clean, closed container.
D Never use used cleaning or testing liquids for these components.
D New parts must not be removed from their original packing material until directly before
use.
D Work on removed components may be carried out only at a workplace specially
equipped for it.
D If removed parts are shipped always use the original packing material of the new part.

Fault table
12
Operating faults and possible causes
We recommend
A repair is only complete when both the damage that occurred and the possible causes have been elimin-
ated. 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 elimination (questions) to pin-point 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 “over-eager” replace-
ment 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 to 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, Lu-
bricants and Coolants for MAN Diesel Engines”.

Fault table
13
x = likely to apply
o = might apply
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. Fuel consumption too high
18. Lubrication oil pressure too low
19. Lube oil pressure too high
20. Lube oil consumption too high
21. Engine too “loud” / mechanical noises
22. Idle speed cannot be adjusted with idle speed operating unit
Possible causes
x x Battery flat, battery lead connections loose or corroded, break in power circuit
x Crankshaft drive blocked
x x Starter solenoid switch sticks (clicks) / damaged, cable connection loose or dam-
aged
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 qual-
ity does not comply with specifications
x x Oil level in oil pan too high
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 the oil circuit defective (does not close, spring fatigued or broken)
x x Heavy 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
clogged)
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 x Piston rings heavily worn, broken
x x Piston pins or crankshaft bearings loose
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 individ-
ual cylinders
x x x Valve seats leaking
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 filter fouled or clogged, charge air system leaking, air intake / exhaust lines
clogged / leaking
x x x x x x x x x Fuel low pressure system: Fuel tank, prefilter, water trap faulty / clogged / mould /
fungal attack, fuel unsuitable / contaminated (paraffin added)
x x x x x x x x Fuel low pressure system: fuel lines leaking, broken, clogged

Fault table
14
x = likely to apply
o = might apply
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. Fuel consumption too high
18. Lubrication oil pressure too low
19. Lube oil pressure too high
20. Lube oil consumption too high
21. Engine too “loud” / mechanical noises
22. Idle speed cannot be adjusted with idle speed operating unit
Possible causes
x x x x x x x Fuel low pressure system: Air in system (turn on ignition when bleeding system)
x x x x x x x x x Fuel low pressure system: Feed pump, main filter
x x x x x o x x Fuel high pressure system: Injectors defective / clogged / leaking / coked
x x x x o Fuel high pressure system: pressure lines − constriction, cavitation, leaking
x x o x x x x o Fuel high pressure system: High-pressure pump worn
x x x x x o Pedal value sensor (driving lever signal) defective: connection lines, short circuit,
interruption
x x EDC rpm sensor defective, lead defective
x x o EDC rpm sensor, polarity reversed
x x x x o o o o EDC detects incorrect engine speed (interference signal on rpm sensor lead)
x x x EDC boost pressure sensor: faulty, incorrect, implausible with atmospheric pres-
sure sensor, line fault
x x o x Exhaust turbocharger leaking or defective
x Turbine and compressor wheel in the turbocharger soiled (running off balance)
x Intercooler leaking, defective
x o x x o x EDC coolant temperature sensor: faulty, line fault
x x x EDC charge-air temperature sensor: faulty, line fault
o x x Radiator fouled or failure of cooling system (temperatures too high)
x Coolant level too low, air in the coolant circuit
x V-belt for coolant pump drive not tensioned correctly
x x Incorrect V-belt tension
x Coolant pump leaking, defective / thermostat defective, does not open
x Coolant lines leaking, blocked or twisted
x Coolant entering combustion chamber (cylinder head / gasket leaking)
x x x o o Power supply to EDC control unit interrupted or battery voltage too low
x o o o EDC control unit defective (internal fault)
x x x x o o o x Incorrect EDC control unit (check MAN part number)
x Afterrunning not completed
x x Thermostat defective
x Engine bearings worn

General notes on engine overhaul
15
The service life of an engine is influenced by very different factors. It is therefore not possible to specify
certain fixed numbers of operating hours for general overhauls.
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 Charging pressure
D Exhaust temperature
D Coolant and lubricant temperature
D Oil pressure and oil consumption
D Smoke emissions
The following criteria greatly influence the length of the engine service life:
D Correct power output setting according to the type of application
D Technically correct installation
D Inspection if installation by authorised personnel
D Regular maintenance as per maintenance plan
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
16
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.
Diagram of the oil flow with unpressurised engines

Commissioning after engine overhaul
17
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 bear-
ings 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 (screw plug).

Engine views D 2876 LE 423
18
11 10 9 8
7
5
5
6
4
321
12 13
14
1516

Engine views D 2876 LE 423
19
À Exhaust turbocharger
Á Crankcase breather valve
Â Relief valve on coolant surge tank
Ã Heat exchanger and coolant surge tank
Ä Alternator
Å Coolant pump
Æ Engine cranking device
Ç Oil cooler housing
È Oil filter
É Hand vane pump
11 Fuse box
12 Oil filler neck
13 Fuel-Service-Center
14 Fuse box
15 Hand priming pump
16 Sea water pump

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