New Generation of 4-Cylinder Inline Engines, OM 651
Contents
1. 43 5 Exhaust valve 6 Piezo injector 1 n a n j _ HI 177171 UNE P01 30 2360 00 4 S 5 Intake valve 8 Valve spring 9 Valve clearance compensation 13 14 Oil pan Special design features Two piece design e Lower section of oil pan made of plastic Noise optimized e Service optimized and cost optimized replacement parts Bolts secured to prevent them being lost e Installation can be checked via special pins on seal 01 45 2329 00 Oil pan 1 Upper section of oil pan 2 Seal with pins i Note Temporary level fluctuations are balanced out by the volume of the housing and the size of the drain bores in the oil level check switch This prevents unnecessary warning messages e g triggered by cornering 3 Lower section of oil pan plastic 4 Bolts with retainer anti loss Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Crankshaft assembly Crankshaft The forged crankshaft with eight counterweights is supported by five bearings for effective vibration damping The radiuses of the crank pins are rolled to give them high strength In addition the connection between the drive gear and crankshaft is friction welded The vibration damper is fixed to the crankshaft with a fo2. 4098 Jo 1098 9jelpeuuoju J9UOISU8 UIEu2 ajzzou 5 Io uieuyo SUIWI J0jesueduioo 92U0409 9O suueag yeyswey sa zzou AeJds IQ SUIJOQ9UUOD pue Yeysyuely JOBICYIOGIN aunssaJd M07 Jo84euo2oqun B41NSsasd YslH ssedXg J83Jl IO 2191 IO JOSUCYOXS 19JEM IO 55 911585924 2 IQ 49924 ued IQ OC MYND 1n24 2 IO 39 Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt This printout will not be recorded by the update service Status 09 2008 40 Oil pump Oil pump The oil pump is volume controlled at the clean oil side and has a rotary vane design The control pressure 15 4 7 bar The oil pump is driven by the gear drive and is equipped with an integrated pressure limiting valve which limits the oil pressure to a maximum of 10 bar As soon as the engine is started the engine oil is drawn in via the intake line with integrated prefilter on the oil suction pipe and pumped to the oil filter module with integrated oil water heat exchanger via the pres sure line During the cold start phase of engine operation the oil water heat exchanger ensures that the oil is heated up more quickly and in the warm up p
3. 44 Rated torque Vacuum pump 44 Roller type cam followers 17 Valve assembly 17 Valve clearance compensation 17 Z Zero quantity calibration 23 Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt This printout will not be recorded by the update service Status 09 2008
4. 4 Exhaust manifold Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Exhaust system Exhaust gas recirculation path Part of the exhaust gas enters the exhaust gas recircu lation system via the exhaust manifold The EGR path 15 made up of the following components e EGR pre cooler e EGR actuator e EGR bypass flap e EGR cooler The incoming quantity of exhaust gas Is controlled by the EGR actuator EGR path 1 EGR actuator 2 Vacuum unit 3 EGR bypass Introduction of New Generation of 4 Cylinder Inline Engines OM 651 s This printout will not be recorded by the update service Status 09 2008 The CDI control unit actuates the EGR actuator via a pulse width modulated signal causing the EGR actu ator to increase or reduce the size of the opening cross section of the EGR valve In order to further improve the efficiency the exhaust gas can be directed via the EGR cooler and cooled further depending on the requirement However if the temperature of the incoming exhaust gas is too low the path to the EGR cooler is closed via a bypass flap and the exhaust gas is guided directly to the charge air manifold The switchover valve for the bypass flap is controlled by a vacuum unit P14 20 2260 00 4 EGR cooler 5 EGR pipe 6 EGR pre cooler 33 Oxidation catalytic converter strea
5. 6 2 12150 191 Jue oo2 Sry 5 6 7 LIAI Josuas ainjesaduiaj JuejooD 1 8 ajalya HA Engine cooling 00 2St2 00 0 my 4 CN l S LIN JOSUCYOXA 19 0 IO 493 2 528 JSNEYXF 9 2 9 MOJJ QUIBUF 0 5 VA Hd x C JOJEIPCY JUBA 8011114 21 10 JASUCYOXA JI0AJ9S84 UOISUeAXA 005 10321 0 13 009 4094 suisnoy 5 8 5 aseo uley 10129 02 005 peau 2 SLIYULIJ 1 8guey x IO uejoop JINIAID SULOOD N MYO OK 37 Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Engine lubrication and oil circuit Lubricating system The engine lubrication system minimizes the mechan ical friction and thus the wear on moving parts In addition the oil pads between the bearings and running surfaces reduce shocks and vibrations A pressure differential valve is installed in parallel to the oil water heat exchanger to ensure that the engine Is lubricated at all times This allows the oil to
6. Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Rear radial shaft sealing ring insertion tool Use For inserting rear radial shaft sealing ring of crankshaft Part number W 651 589 01 61 00 FG 03 Set B Assembly tool Use For fixing balance shafts in place when disassembling and assembling drive gears Part number W 651 589 02 63 00 FG 03 Set C Front radial shaft sealing ring insertion tool Use For inserting front radial shaft sealing ring of crankshaft Part number W 651 589 00 61 00 FG 03 Set B Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt This printout will not be recorded by the update service Status 09 2008 Engine P58 20 2245 00 P58 20 2248 00 58 20 2242 00 10015 53 Engine P58 20 2241 00 54 gt Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Abbreviations AGR Exhaust gas recirculation EGR CAN Controller Area Network CDI Common rail Direct Injection CO Carbon monoxide CO Carbon dioxide DAS Diagnosis Assistance System DPF Diesel Particulate Filter EOBD European On Board Diagnosis Euro NCAP European New Car Assessment Program HC Hydrocarbon HFM Hot film mass air flow se
7. Generation of 4 Cylinder Inline Engines OM 651 gt This printout will not be recorded by the update service Status 09 2008 4 Clean air line 5 Charge air cooler 29 Air supply Intake port shutoff The intake port shutoff 5 function ensures the best possible ratio between air mixing and air mass in all engine load conditions and thus an optimal fill level This optimizes the exhaust characteristics and engine output The charge air manifold is made of plastic and the flaps are made of metal In the charge air manifold there is a permanently open tangential intake port and a flap controlled spiral intake port for each cylinder The flaps are connected to each other by a shaft The CDI control unit controls the position of the flaps based on performance maps When the engine switches from the partial load range to the full load range the flaps in the spiral intake ports are opened according to performance maps In the event of a fault or if the supply voltage is inter rupted the flaps in the spiral intake ports are mechan ically opened by the return springs Charge air manifold 1 Actuator motor 2 Adjustment flap 3 Spiral intake port 4 Tangential intake port 5 Charge air manifold Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Air supply Throttle valve
8. New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Common rail injection Piezo injectors An important component of the new Common Rail technology are the piezo injectors which are an entirely new development The injector needle is actu ated directly by a piezo ceramic actuator instead of being moved by a hydraulic support system Compared to a conventional fuel injector the piezo injector injects fuel into the combustion chamber more rapidly with better atomization and with greater precision A special feature of this system 15 that the piezo injec tors open upon a voltage rise and not upon a voltage drop PO7 03 2243 00 Piezo injector AN Warning Due to the risk of engine damage no connections on the injection system may be disconnected while the engine is running The injector coupling may not be disconnected and switched to ground while the engine is running because this would trigger an injection During engine operation a high voltage of up to 250 V is applied to the piezo injectors AN Warning Risk of death Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt 21 This printout will not be recorded by the update service Status 09 2008 Common rail injection Advantages of the new injection technology The advantages gained with the new technology include a larger avail
9. OIS HPC R822 W002 D 0546 Stuttgart 2008 by Daimler AG This document including all its parts is protected by copyright Any further processing or use requires the previous written consent of Daimler AG Department GSP OIS HPC R822 W002 D 70546 Stuttgart This applies in particular to reproduction distribution alteration translation microfilming and storage and or processing in electronic systems including databases and online services Image no of title image PO 1 00 3119 00 Order no of this publication 6516 1364 02 08 2008 This printout will not be recorded by the update service Status 09 2008 Contents Preface 5 T Brief description 6 Engine data 7 Highlights 8 Engine views 9 System comparison 10 At a glance 11 12 Cylinder head 13 Oil pan 14 Crankshaft assembly 15 Valve assembly 17 Gear drive 18 Belt drive 19 l Common rail injection 20 Charging 24 Air supply 29 Exhaust system 32 Exhaust system 34 Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt This printout will not be recorded by the update service Status 09 2008 Contents Engine cooling 36 Engine lubrication and oil circuit 38 Oil pump 40 Coolant pump 41 Engine control unit 42 Glow system 43 Vacuum control 44 Emission reduction 46 New features 48 Engine 50 Abbreviations 55 Index 56 I
10. be routed around the oil water heat exchanger Oil circuit All of the moving components of the engine are lubri cated and or cooled with engine oil via the oil circuit of the engine The oil circuit of the engine is supplied with engine oil via the oil pump In addition the vacuum pump 15 driven and supplied with engine oil via the oil pump The following components in the crankcase are supplied with engine oil via the main oil duct Crankshaft bearings Connecting rod bearings Intermediate gears Oil spray nozzles The two turbochargers are supplied with engine oil via a bypass of the main oil duct The oil supply for the cylinder head branches off from the main oil duct The following lubrication points in the cylinder head are supplied with engine oil Cam chain tensioner Intake camshaft e Exhaust camshaft e Hydraulic valve clearance compensator The engine oil is returned to the oil pan via return ducts 18 10 2179 00 Oil pump gt Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Engine lubrication and oil circuit 4407145 ejzzou Keds 10 8 81209 00 0922 00 8 LELA peay 2 1899 OSDOXUUJ 497 4 IO jsneux3 IO ued IO
11. compensation clearance compensation Turbocharger type 1 stage turbocharging with 2 stage turbocharging with variable turbine geometry fixed geometry Boost pressure control Electric Pneumatic Measures for low emission Intake port shutoff Intake port shutoff EGR combustion exhaust gas recirculation cooling and EGR bypass EGR with separate EGR cooler Fuel injector type Solenoid injector Directly controlled piezo injector Fuel injector diameter mm 17 19 Firing order 1 3 4 2 Oil pump drive Simplex chain Gear drive Alternator current rating A 200 180 Engine weight DIN dry approx kg 190 203 10 Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Objective Optimized comfort Improved fuel economy Compliance with exhaust emissions standards Euro 5 standard At a glance Measures on engine 651 Overview stiffer crankcase with full length crankshaft bearing bridge Wide crankshaft main bearing friction optimized with center bearing Two low positioned Lanchester balance shafts for smooth engine running Plastic cylinder head cover with integrated ventilation Maintenance free long life simplex chain as camshaft drive Engine cover with adjusted acoustic damping Optimized flow conditions air ducting intake ports Dual stage turbocharging Optimized charge air cooling and exhaust gas recirculation coo
12. coolant circuit It is made of plastic which makes a contribution to weight reduction Cross section of coolant pump Belt pulley Control rod Regulating valve Evacuation chamber Vacuum fitting O14 C5 Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt This printout will not be recorded by the update service Status 09 2008 Function The coolant pump is driven via the belt pulley by means of a poly V belt The rotational movement of the belt pulley is transferred to the shaft via the hub The impeller is driven by the shaft which causes the coolant to circulate The coolant flow can be stopped by vacuum via the switchover valve of the coolant pump which is located on the left on the throttle valve actuator In this case a regulating valve slides over the impeller thus closing the coolant feed P20 10 2255 00 Impeller 7 Coolant outlet 8 Power diaphragm 9 Rod seal 10 Compression spring 41 Engine control unit CDI control unit The CDI control unit is located on the air filter housing The CDI control unit serves as an interface between the The CDI control unit is equipped with cooling fins at drive train CAN CAN and the chassis CAN CAN the bottom which project inside the air filter housing The engine control system is equipped with fault and are cooled by the intake air memory and powerful diagnostic functions for moni The task of
13. 2000 2400 2600 3200 3600 4000 4400 4600 5200 n 1 min 00 01 3118 00 Engine 651 911 n Engine speed Torque m Output Introduction of New Generation of 4 Cylinder Inline Engines 651 gt 7 This printout will not be recorded by the update service Status 09 2008 Highlights New features Thermal management Based on the use of the latest innovative technologies The new thermal management system consists of engine 65 1 sets a new standard in terms of output and torque characteristics economy exhaust emission levels and smooth running The engine features a number of new developments which cannot be found in this combination in any other series produced passenger car diesel engine Shutoff capable coolant pump Cylinder head with two piece water jacket e Shutoff capable oil spray nozzles combined with piston crown cooling Oil pump volume controlled at clean oil side Technology The most important technical features of the new engine are Dual stage turbocharging with fixed geometry e Directly actuated piezo injectors Gear drive in combination with a chain drive on the output side e Intake air cooled engine control unit on air filter housing Main bearing bridge with integrated Lanchester housing Two Lanchester balance shafts Drive gear friction welded to crankshaft e Vibration dampers quadruple bolted Universal timing case cover for adaptation to various
14. AN Risk of engine damage safety information for handling ceramic glow plugs e Only use glow plugs from unopened original packaging f a glow plug is dropped on the floor it must not be used e Important Engine damage can occur because glow plugs are very sensitive to shock Hairline cracks may develop in the ceramic element As a consequence parts may become detached and drop into the combustion chamber while the engine is running Always handle glow plugs with the utmost care The glow plugs must be removed before removing the cylinder head and must not be reinstalled until the cylinder head has been installed Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt Glow system A distinction is drawn between the following glowing types Preglowing Start ready glowing Afterglowing Diagnostic glowing DPF glow function Emergency glowing P15 20 2181 00 Ceramic glow plug i Note If a fault occurs in the preglow system glow plugs or lines this is indicated by the preglow indicator lamp and the fault is also stored in the CDI control unit This printout will not be recorded by the update service Status 09 2008 Electrical and electronic systems 43 Vacuum control Vacuum control The vacuum pump is driven indirectly via the oil pump The following components are actuated by a pulse drive It generates vacuum pressure and is connected width modulated signal t
15. New Generation of 4 Cylinder Inline Engines OM 651 Introduction into Service Manual Ws a o EE d Fr This printout will not be recorded by the update service Status 09 2008 Mercedes Benz Service Introduction of New Generation of 4 Cylinder Inline Engines OM 651 Daimler AG Technical Information and Workshop Equipment GSP Ol D 70546 Stuttgart This printout will not be recorded by the update service Status 09 2008 Information and copyright Ordering workshop information All printed workshop information from GSP Ol such as Introduction into Service Manuals System Descriptions Function Descriptions Technology Guides Tech nical Data Manuals and adhesive labels can be ordered as follows Within Germany Through our GSP OI Shop on the Internet Link http gsp ti shop de or alternatively E mail customer support daimler com Phone 49 0 1805 010 7979 49 0 1805 010 7978 Outside Germany Please get in touch with the contact person responsible for your market Product portfolio You can also find comprehensive information on our complete product portfolio in our Internet portal Link http open aftersales daimler com Questions and suggestions If you have any questions or suggestions concerning this product please write to us E mail customer support daimler com Fax 49 0 18 05 0 10 79 78 or alternatively Address Daimler AG GSP
16. New Generation of 4 Cylinder Inline Engines OM 651 gt This printout will not be recorded by the update service Status 09 2008 26 Charging Boost pressure control during wide open throttle operation up to 1 200 rpm The boost pressure control flap LRK is almost closed up to an engine speed of 1 200 rpm during wide open throttle operation In this state the entire exhaust flow flows over the turbine wheel of the high pressure turbocharger HD Lader to the turbine wheel of the low pressure turbocharger ND Lader and then to the exhaust system The majority of the exhaust energy acts on the turbine wheel of the HD Lader which generates the main part of the required boost pressure Despite the low exhaust flow this produces a high boost pressure which builds up very quickly The remaining exhaust energy acts on the turbine wheel of the ND Lader which drives the compressor impeller via the supercharger shaft The ND Lader thus does not act as a hydrodynamic retarder The wastegate and charge air bypass flap are closed in this Operating condition P09 40 2348 00 Schematic illustration of boost pressure control during wide open throttle operation up to 1 200 rpm A Intake air 4 Wastegate 10 Exhaust manifold B Exhaust flow 5 Charge air bypass flap 11 Exhaust gas recirculation EGR Air filter pre cooler 1 High pressure turbocharger Charge air cooler 12 EGR actuator 2 Low pre
17. The throttle valve actuator uses the throttle valve to influence the air volume fed to the engine and the mixing ratio of charge air and recirculated exhaust gas mixed in downstream of the throttle valve When the engine is switched off the throttle valve is closed This keeps engine vibrations at a low level when the engine is switched off Throttle valve 1 Throttle valve 2 Throttle valve actuator 3 Charge air manifold Introduction of New Generation of 4 Cylinder Inline Engines OM 651 ze 31 This printout will not be recorded by the update service Status 09 2008 32 Exhaust system Exhaust gas recirculation The exhaust system of engine 651 combines two tech nologies for emission reduction Exhaust gas recircu lation EGR reduces emissions of nitrogen oxide NO and exhaust treatment reduces the emission of hydro carbons HC and soot particles With exhaust gas recirculation part of the exhaust flow is guided back through the EGR path to the charge air Exhaust gas recirculation 1 EGR pre cooler 2 EGR cooler The recirculated exhaust gas enters the EGR path via a pre cooler There it is either cooled according to its temperature or fed directly to the charge air The exhaust air mixture enters the combustion chamber directly via the charge air manifold Exhaust gas recirculation reduces the oxygen O concentration and combustion temperature P14 20 2258 00 3 Charge air manifold
18. able injection volume as well as particularly fine and rapid metering of injection quan tities due to finely tuned switching times In combina tion with direct actuation of the piezo injectors by the CDI control unit the fuel injection process can be even more precisely adjusted to the respective load and rpm situation This is achieved for example through precise multiple injections which enable fuel consumption combustion noise and exhaust emis sions to be reduced even further The engine also runs significantly more smoothly at idle Injection quantity The injection timing point and injection period are determined by the following factors e Direct actuation of piezoceramic element e Opening closing speed of the nozzle needle Needle lift Nozzle geometry with 7 hole nozzle module Engine load e Torque request i Note When working on the injection system e g piezo injector pressure lines rail high pressure pump particular care must be given to quality and clean liness as even the most minor contamination may very quickly lead to complaints about engine running characteristics and damage Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Common rail injection Injection quantity correction Zero quantity calibration Injection quantity correction consists of two proce The friction produced
19. anifold 14 EGR bypass flap Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt 27 This printout will not be recorded by the update service Status 09 2008 Charging Boost pressure control during wide open throttle operation as of 2 800 rpm The LRK is fully open as of an engine speed of In order to prevent pressure loss and additional 2 800 rpm This causes almost the entire flow of warming of the charge air as it flows through the high exhaust gas to be fed nearly without loss to the low pressure compressor the charge air bypass flap is pressure turbine via the bypass duct and limits the opened so that the main part of the air flow 15 guided level of exhaust back pressure to the charge air cooler along a direct low loss path This procedure means that the HD Lader no longer The wastegate Is used to regulate the turbine output makes any contribution to increasing the boost pres of the low pressure turbine in the engine performance sure The HD Lader has reached its choking limit This as required and depending on the load condition means that it can no longer generate boost pressure and in the event of further loading the turbine speed would drop off significantly Depending on the load condition the HD Lader can build up a high level of boost pressure at low engine speeds and prevent overload of the ND Lader at high engine speeds 09 40 2350 00 Schematic illustration of
20. bocharger can be replaced individually with the turbocharger installed Attention must be paid to the following important points e The color coding on the control lines e The nuts secured with temperature resistant paint Oil spray nozzles The oil spray nozzles can be replaced individually The exact seating is defined by a positioning screw Crankshaft The vibration damper TSD has a fourfold threaded connection This means that the forces acting on the damper are distributed across four bolts which reduces the stress on each specific bolt A special tool is available for easy installation The signal from the camshaft sensor is used by the CDI control unit as a substitute value for engine control If the sensor for the crankshaft fails the engine can be operated and started in emergency operation mode using the camshaft sensor Seals The seals in the exhaust area are equipped with pins and polygonal curves The seals are prefixed and the screws are conveniently secured against falling out which simplifies installation In addition the seals are equipped with an installation checking pin This makes it possible to check whether the seal is installed after assembly 09 41 2550 00 Seal with installation checking pin arrow on charge air manifold Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Piezo inje
21. boost pressure control during wide open throttle operation as of 2 800 rpm A Intake air 4 Wastegate 10 Exhaust manifold B Exhaust flow 5 Charge air bypass flap 11 Exhaust gas recirculation EGR Air filter pre cooler 1 High pressure turbocharger Charge air cooler 12 EGR actuator 2 Low pressure turbocharger 8 Throttle valve actuator 13 EGR cooler 3 Boost pressure control flap LRK 9 Intake manifold 14 EGR bypass flap 28 Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Air supply Air ducting The hot film mass air flow sensor HFM is located in the clean air line downstream of the air filter housing It determines the mass and temperature of the intake air and makes the measurement results available to the motor electronics as input factors The low pressure turbocharger draws in clean air through the clean air line and air filter and compresses it The air compressed by the turbochargers flows through the charge air cooler where it is cooled The throttle valve actuator influences the air volume fed to the engine and the mixing ratio of charge air and recirculated exhaust gas mixed in downstream of the throttle valve The air mixture is then fed directly to the combustion chamber via the charge air manifold Air ducting 1 Air filter housing 2 Throttle valve 3 Charge air manifold Introduction of New
22. ctor The piezo injectors are marked with a 24 digit I2C code The 120 coding permits even more accurate tuning injection quantity and injection period of the indi vidual piezo injectors when new If a piezo injector is replaced the CDI control unit must be supplied with this coding via Star Diagnosis Data matrix code some components feature a matrix code The codes are predominantly applied using laser technology This code contains information which is useful for quality and assembly related purposes only The code has no use for service staff New features Service information ay 7 4 j AMT AM ji PO7 16 3483 00 2 e 7 Piezo injector 1 Data matrix code 2 2 code i Note The new features and notes shown here are not intended as repair instructions Further information on repairing and maintaining engine 651 can be found in the Workshop Informa tion System WIS Introduction of New Generation of 4 Cylinder Inline Engines OM 651 zz 49 This printout will not be recorded by the update service Status 09 2008 Special tools Engine Socket wrench Use For removing shift valve for controlling piston cooling Part number W 651 589 00 09 00 FG 18 Set B Hold down device Use Fixing camshaft in place when tightening or loosening camshaft sprockets Part number W 651 589 01 40 00 FG 05 Set C Assembly inserts Use For pressing on and riveting oute
23. during opening and closing of dures the piezo injectors causes wear on the nozzle seat of the nozzle needle This causes a change in the injec e Main injection quantity correction ux o tion quantity over the service live of the injector e Zero quantity calibration This change in the injection quantity can be corrected by adjusting the actuation duration zero quantity cali Main injection quantity correction bration On engines with the Delphi injection system correction is performed with the help of two knock With main injection quantity correction the injected sensors fuel quantity is corrected using the oxygen sensor upstream of the catalytic converter The injection quantity is changed until the specified lambda value stored in the CDI control unit is reached 5 P CDI injection system 1 Fuel heating element 4 Railpressure sensor High pressure pump 2 Fuel filter housing 5 Pressure line 8 Quantity control valve Rail 6 Piezo injector 9 Pressure regulator valve Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt 23 This printout will not be recorded by the update service Status 09 2008 24 Charging General With engine 651 Mercedes Benz has continued the development of dual stage turbocharging in its 4 cylinder inline diesel engines in a passenger car the predecessor with dual stage turbocharging 15 engine 646 in the Mercedes Benz Sprinter Desi
24. ewly designed thermal management system incorporates the following function sequences Maximum heating combustion e Overheating protection e Post start phase Exhaust emissions are reduced by the extended thermal management system The table below shows the new measures and the associated results Exhaust treatment Many pollutants can be converted before they leave the vehicle through exhaust treatment in the exhaust system The use of an oxidation catalytic converter and a diesel particulate filter DPF enables the following pollutants in the exhaust gas to be reduced e Nitrogen oxides e Hydrocarbons HC Carbon monoxide Soot particles Switchable oil spray nozzles and coolant pump Two piece water jacket Optimized EGR cooling output Oil pump volume controlled at clean oil side This speeds up the warm up phase after a cold start This improves control capabilities and heat dissipation The temperature and oxygen concentration in the combustion chamber are lowered which produces a cooler fuel air mixture and reduces soot formation The exhaust flow produced by the engine is reduced This reduces the drive resistance Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 47 Service information 48 New features Dual stage turbocharging The vacuum units of the tur
25. fore the information available there reflects the latest technical status of our vehicles The contents of this brochure are not updated and no provision is made for supplements We will publicize modifications and new features in the relevant WIS documents The information presented in this Intro duction into Service manual may therefore differ from the more up to date information found in the WIS All information relating to technical data equipment and options is valid as of the copy deadline in July 2008 and may therefore differ from the current production configuration Daimler AG Technical Information and Workshop Equipment GSP OI Brief description Engine model series 651 The new generation of the 4 cylinder diesel engine 651 equipped with the second generation Common Rail Direct Injection CDI system from Delphi will be launched on the market as of October 2008 Engine 651 has a rated output of 150 kW with a displacement of 2 143 anda consumption of just 5 4 liters of diesel fuel per 100 kilometers Despite this high output and an engine torque of 500 Nm emissions of have been further reduced In addi tion the engine meets the future Euro 5 standard A central feature of the new engine is its dual stage turbocharging system The system combines a small high pressure turbocharger with a large low pressure turbocharger Engine 651 also features two Lanchester balance shafts to make the eng
26. ft by acenter bolt The center bolt of the camshaft has a left hand thread v wf Exhaust camshaft with sensor wheel 1 Drive gear 2 Exhaust camshaft Crankshaft assembly Sensor wheel The sensor wheel is fixed to the exhaust camshaft In combination with the Hall sensor the sensor wheel makes it possible to determine the camshaft position and rpm The Hall sensor generates a magnetic field through a built in permanent magnet The magnetic field 15 peri odically interrupted by an orifice plate on the sensor wheel while the engine 15 running The signal which this generates is used by the CDI control unit and serves as a substitute signal for emergency engine operation if the position sensor for the crankshaft fails 05 20 2328 00 3 Sensor wheel with orifice plate s Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Valve assembly Valve assembly with hydraulic valve clearance compensation The valve assembly was modified with the aim of opti mizing friction and reducing the moved masses The camshafts control two intake valves and two exhaust valves per cylinder This valve timing system uses low friction roller type cam followers with hydraulic valve clearance compensation 05 00 2087 00 Valve assembly 1 Slide rail 6 Sensor wheel with orifice plate 2 Ti
27. gh temperatures e Post injection e Exhaust gas recirculation with intake air throttling e DPF glow function 14 40 2385 00 Schematic illustration of oxidation catalytic converter and DPF 1 Oxidation catalytic converter CO Carbon dioxide Nitrogen 2 DPF 0 HC Hydrocarbon CO Carbon monoxide HO Water NO Nitrogen oxide PM Particulate matter 34 Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Exhaust system DPF regeneration The exhaust back pressure increases as the soot load of the DPF increases A sensor measures the pressure differential upstream of and downstream of the DPF and forwards this information to the engine control unit Regeneration of the DPF is initiated when the threshold value stored there is reached Regeneration during driving operation 15 performed on average after 800 to 1 000 km depending on soot emissions and filter size Exhaust system 1 Oxygen sensor upstream of catalytic converter 2 Oxidation catalytic converter 3 Diesel particulate filter i Note If the exhaust temperature required for regeneration is not reached during normal driving operation selective post injection into the combustion chambers is performed to increase the exhaust temperature The regeneration procedure only takes several minutes and depends on Engine speed e Vehicle speed e E
28. gn The dual stage turbocharging system incorporates two turbochargers that differ in size and a bypass control system to achieve a high rated output and air mass throughput even at low rpm The boost pressure 15 regulated via the boost pressure control flap LRK the wastegate and the charge air bypass flap The control operations take into account the respective engine torque request based on performance maps Advantages of dual stage controlled turbo charging This complicated control system which uses two turbochargers to feed charge air to the engine in accordance with its requirements has the following advantages Noticeably more dynamic start off behavior No start off sluggishness turbo lag Well balanced driving characteristics Noticeably better driving performance throughout the entire rom range Good acceleration high torque at low rpm e High pressure turbocharger is designed to build up boost pressure rapidly at low engine speeds Low pressure turbocharger is designed to build up high boost pressure with high gas flow at medium and high engine speeds The effects on the engine include Better cylinder charging and thus higher output e Well balanced torque curve at extremely high level e Improved rated output with a well balanced torque curve e Lower fuel consumption Long service life and high reliability Reduced nitrogen oxide NO emissions Function sequence of boost p
29. hase it ensures that the engine oil is cooled adequately If the oil flow is insufficient the oil can be directed past the oil water heat exchanger via the bypass valve installed in parallel Only after this does the engine oil enter the oil filter unit The oil then flows from outside to inside and is cleaned in the process If the flow is insufficient e g due to a high level of contamination the oil filter bypass valve installed in parallel routes the oil flow around the oil filter Oil spray nozzles The oil spray nozzles and the associated oil feed for piston crown cooling are actively shut off by the shutoff valve of the oil spray nozzles The oil spray nozzles are shut off by the CDI control unit in the post start phase under the following conditions Engine oil temperature greater than 10 C And The max shutoff duration depending on intake air and engine oil temperature has not yet been reached Or he engine speed or the injection quantity has not yet reached a specified limit value If the oil spray nozzles are ever switched on they are no longer shut off for as long as the engine is running P18 10 2178 00 Cross section of oil pump s Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Coolant pump The coolant pump ensures that the coolant circulates in the
30. his printout will not be recorded by the update service Status 09 2008 Cylinder head General The cylinder head is made of high strength aluminum It is equipped with two camshafts and four valves per cylinder The cylinder head cover is made of plastic with integrated ventilation The cylinder head is char acterized by the following new features Maximum ignition pressure of 200 bar previously 160 bar e Tangential and spiral intake ports Bore for piezo injector of 19 mm diameter The upper duct of the two piece water jacket supplies the cylinder head with coolant The advantages of the two piece water jacket include Greater structural rigidity Better heat dissipation Improved thermal management The improved thermal management system is particu larly beneficial in those areas which are exposed to very high temperatures The high ignition pressure of 200 bar is only made possible by targeted cooling of the individual components The increased pressure potential and optimized injection quantity are respon sible for the high engine torque of 500 Nm and the engine output of 150 kW co i Cross section of cylinder head 1 Ventilation 4 Glow plug 2 Main bearing bridge 3 Cylinder head cover Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt This printout will not be recorded by the update service Status 09 2008
31. ine run more smoothly In order to meet the new legal requirements of the Euro NCAP crash tests with respect to improved pedestrian protection the gear drive has been located on the output side together with the chain drive The increased space between the engine and engine hood reduces the risk of injury for pedestrians Engine 138 2 6 displacement and 33 kW output Installed in the Mercedes Benz 260 D the world s first diesel passenger car in 1936 1P01 10 2970 00 Engine 651 2 2 displacement and 150 kW output Installed in the C Class as of October 2008 i Note A detailed description of the new CDI system can be found in the System Description for engine 65 1 Order number 6516 1363 02 Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Engine data M Displacement 2 148 2 143 0 2 Rated output kW 125 150 20 at rom 3 800 4 200 Rated torque Nm 400 500 25 at rom 2 000 1 600 1 800 Maximum rpm rom 4 900 5 200 6 a ee L sE d 7 Eze Es a Fn Pesce EEE esca Fei TEE a Tee em md a Et mm So Soe j 600 1200 1600 2000 2400 2800 3200 3600 4000 4400 4800 5200 n 1 P00 01 3117 00 Engine 646 821 EVO E 5 600 1200 1600
32. j aunssaJd 15008 JBAOYDJIMS Ssed q 002 M23 Ja9onpsueJ eJnssaJd JOJJUOD 28 52 00 BEOZ 60 204 1A CELA GBA V LEA E6A A 404 494 14 JUBA JI0A18S84 dey ssed q ajesajse dey aunssaJd 15003 Gl cl cl ssedXg 49 002 423 005 peay aJnssaJd MOLE UOI228JIp 1 L16 LG9 uo UMOYS W JS S l rT Cb 45 Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt This printout will not be recorded by the update service Status 09 2008 Emission reduction Emission reduction measures The wide range of new technical features used in the development of engine 651 have made it possible to reduce the level of raw emissions even further The engine complies with the Euro 5 standard even without BlueTEC technology The new engine has the potential to fulfill the limit values for the Euro 6 stan dard and the US BIN5 standard Mechanical measures Oil pump volume controlled at the clean oil side with regulated pressure level performance map e Friction optimized vacuum pump Piston pins with PVD coating Technical implementation Raw emissions have been further
33. l and operating unit The position of the coolant thermostat is used to precisely adjust the quantity of coolant flowing to the radiator or direct to the coolant pump This regulates the temperature of the coolant in the coolant circuit The coolant thermostat is controlled via the integrated heating element The coolant pump and the heating element are controlled via the CDI control unit When the coolant thermostat is closed the coolant flows back to the coolant pump and is fed back into the circuit Once the engine has reached operating temperature the coolant thermostat is opened and the coolant circuit becomes active The radiator is then incorpo rated into the coolant circuit A filling line between the coolant expansion reservoir and the radiator balances out the coolant level A vent line ventilates the coolant system between the coolant expansion reservoir and the housing of the coolant thermostat i Note The heating element of the coolant thermostat may not be removed disassembled from the ther mostat housing The predetermined opening point shifts if the housing is damaged or if fluid enters the housing More detailed information on this can be found in the Workshop Information System WIS amp Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 4o0jenjoe 528 jsneux3
34. ling Reduction in friction through gear drive and balance shafts mounted on roller bearings Optimized shape of combustion chamber 7 hole injection nozzles More precise injection times Optimized air ducting Exhaust gas recirculation EGR with EGR pre cooler and EGR cooler EGR valve and switched EGR bypass Electric intake air throttling Shutoff capable coolant pump and shutoff capable oil spray nozzles Exhaust system with oxidation catalytic converter and diesel particulate filter Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt 11 This printout will not be recorded by the update service Status 09 2008 Crankcase General When engine 651 was developed the design of the The new design concept provides the following advan crankcase was based on an overall concept with opti tages mized spatial features Accordingly the gear drive with the oil pump drive and the Lanchester balance shafts are positioned on the output side The cast iron crankcase 15 manufactured by sand casting 4cm shorter crankcase compared to predecessor version Improved pedestrian protection through positioning of gear drive and camshaft drive on output side e Universal timing case cover for adaptation to various transmission models P01 40 2238 00 Crankcase 1 Crankcase 2 Oilspray nozzle shutoff valve 12 s Introduction of New Generation of 4 Cylinder Inline Engines OM 651 T
35. m of the turbocharger inside a stainless steel housing dized as follows Before oxidation After oxidation 200 0 2005 50 240 460 The oxidation catalytic converter is part of the exhaust system and 15 located the exhaust tract down The ceramic body is made of highly temperature resis tant magnesium aluminum alumosilicate and has several thousand small passages running all the way though it The ceramic monolith reacts extremely sensitively to physical stress and is fixed in place The individual pollutant components are oxi Exhaust system Diesel particulate filter DPF The diesel particulate filter DPF forms a unit with the oxidation catalytic converter The ceramic DPF is made of silicon carbide and coated with platinum The individual channels open out alter nately to the front or to the rear and are separated from each other by porous filter walls When the unfiltered exhaust gas flows through the porous ceramic honeycomb filter the soot particles are held back by the porous filter walls The CDI control unit measures the load condition of the DPF via the pressure differential sensor The exhaust pres sure upstream of and downstream of the DPF 15 measured for this purpose Regeneration of the DPF is initiated once a defined value is reached Tempera tures of over 600 C are necessary to burn off the soot The CDI control unit initiates the following steps in order to reach these hi
36. ming chain 7 Roller type cam followers 3 Camshaft drive gears 8 Hyaraulic valve clearance compensator 4 Intake camshaft 9 Chain tensioner 5 Exhaust camshaft 10 Timing chain drive gear Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt 17 This printout will not be recorded by the update service Status 09 2008 Gear drive Gear drive One of the most important innovations is the gear The following components are driven by the new gear drive in combination with a chain drive on the output drive system side The reduction in the vibrations produced by the crankshaft results in a noticeably smoother running Lanchester balance shafts Oil pump engine Hi High pressure pump e Vacuum pump via continuous central drive shaft of oil pump S x Gear drive 1 Intermediate gears 4 Orland vacuum pump drive gear 2 Crankshaft gear 5 Drive sprocket 3 Lanchester drive gears 6 High pressure pump drive gear 18 amp Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Belt drive Belt routing The ancillary assemblies are driven by a single piece low maintenance poly V belt The poly V belt is tensioned by an automatic belt tensioner with tensioner pulley Belt routing 1 Alternator 4 Coolant pump 7 Refrigerant compressor 2 Belt pulley 5 Power steering pump 8 Guide pulley 3 G
37. nsor Water IHU Internal high pressure forming LIN Local Interconnect Network NEFZ New European Driving Cycle NEDC system for determining consumption NO Nitrogen oxides 0 Oxygen PVD Physical Vapor Deposition TSD Vibration damper WIS Workshop Information System Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt 55 This printout will not be recorded by the update service Status 09 2008 56 nons A Air ducting Air supply B Balance shaft Belt drive Belt routing Boost pressure control Bore C Camshafts CDI control unit Charging Choking limit measures Combustion system Compression ratio Connecting rods Coolant pump Cooling Cooling circuit Crankcase Crankshaft Crankshaft assembly Cylinder head 29 29 15 19 19 26 10 16 42 24 28 46 10 10 15 41 36 37 12 15 15 13 D Data matrix code Diesel particulate filter Displacement E Emission reduction Engine configuration Engine cooling Engine weight Exhaust gas recirculation Exhaust gas recirculation path Exhaust treatment G Gear drive Glow system Injection quantity correction Injection technology Instant Start System Intake port shutoff Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be reco
38. ntroduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Preface Dear Reader This Introduction into Service Manual presents the new 4 cylinder inline diesel engine 651 from Mercedes Benz It allows you to familiarize yourself with the technical highlights of this new engine in advance of its market launch This brochure primarily intended to provide information for people employed in service mainte nance and repair as well as for aftersales staff It is assumed that the reader is already familiar with the Mercedes Benz model series and major assemblies currently on the market In terms of the contents the emphasis in this Intro duction into Service Manual is on presenting new and modified components systems system components and their functions This Introduction into Service Manual aims to provide an overview of the technical innovations and an insight into their complicated designs Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt This printout will not be recorded by the update service Status 09 2008 However this Introduction into Service Manual is not intended as a basis for repair work or technical diag nosis For such needs more extensive information is available in the Workshop Information System WIS and in the Diagnosis Assistance System DAS WIS is updated monthly There
39. o the vacuum system via its central line to the brake Boost pressure control flap pressure transducer booster The system incorporates The boost pressure control flap opens e Vacuum reservoir steplessly and controls the exhaust flow Wastegate control pressure transducer between the high pressure turbocharger and Boost pressure control flap pressure transducer low pressure turbocharger EGR cooler bypass switchover valve e Charge air bypass flap switchover valve Coolant pump switchover valve Wastegate control pressure transducer The wastegate opens steplessly Part of the exhaust flow is directed past the low pressure turbocharger to the exhaust system e Charge air bypass flap switchover valve The bypass flap opens and relieves the load on the high pressure turbocharger e EGR cooler bypass switchover valve The bypass upstream of the EGR cooler opens and the exhaust flow is directed through the EGR cooler Coolant pump switchover valve The coolant flow to the coolant pump is closed off by the mechanical control components integrated in the coolant pump IT P07 09 2038 00 Vacuum pump 44 amp Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Vacuum control JAAOYDJIMS Juejooy JBAOYIIMS dey ssed q asl1eyy J92npsueJ ainssald de
40. r link plates of bush chain Part number W 651 589 04 63 00 FG 05 Set C 50 gt Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 58 20 2239 00 58 20 2244 00 58 20 2251 00 Engine Leak test adapter Use For leak testing charge air system Part number W 651 589 02 91 00 FG 09 P58 20 2249 00 Set B Counterholder Use Forholding pinion of high pressure pump during disassembly and assembly Part number W 651 589 04 40 00 FG 07 Set B P58 20 2250 00 Valve test adapter Use For measuring return quantity at pressure regulating valve Part number W 651 589 01 91 00 FG 07 P58 20 2247 00 Set B Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt This printout will not be recorded by the update service Status 09 2008 Special tools 51 Special tools Engine 3 pin adapter cable Use For testing Hall sensor on camshaft Part number W 651 589 01 63 00 FG 15 Set 58 20 2246 00 5 pin adapter cable Use For testing resistances and voltages e g on actuators for exhaust gas recirculation throttle valve and intake port shutoff Part number W 651 589 00 63 00 FG 15 Se t 58 20 2243 00 Extraction claw Use For knocking out fuel injectors Part number W 651 589 00 33 00 FG 07 Set B P58 20 2240 00 52 amp Introduction of New
41. rded by the update service Status 09 2008 49 34 46 10 36 10 32 33 47 18 43 23 20 43 30 Index L 5 Lubricating system 38 Seals 48 Sensor wheel 16 M opecial tools Main injection quantity correction 23 3 pin adapter cable 52 5 pin adapter cable 52 N Assembly inserts 50 Assembly tool 53 Number of cylinders 10 CounterholdeP uomo eos ov 81 54 Extraction claw 52 O Front radial shaft sealing ring insertion tool 53 Oil circuit 88 Hold down device 50 Oil 14 Leak test adapter 51 VIRAL LLIRLIR Rear radial shaft sealing ring insertiontool 53 OU PUMP P he Sg 0 Socket wrench 50 Oilspraynozzles 40 Valve test adapter 51 Oxidation catalytic converter 34 Stroke 10 Switchover valve P Charge air bypass flap 44 44 Performance graph 7 EGR cooler aw oor de Piezo injector 21 49 Pressure transducer T Boost pressure control 44 Thermal management 8 36 47 Wastegat trol 44 dba Throttle valve 31 R V Rated output Vacuum control
42. reduced by opti mizing the following components involved in the oil circuit he spray nozzle for the timing chain has been omitted e The control pressure has been lowered to 2 5 bar e Shutoff capable piston crown cooling e Lanchester balance shafts supported by roller bearings ntermediate gears e Reduced pressure resistance Reduction of CO emissions The new Common Rail technology provides the basis for greater injection timing flexibility which produces a smoother running engine with lower fuel consump tion and reduced emissions This has allowed the level of emissions to be reduced by up to 13 The new features responsible for this improvement include the increase in rail pressure by 400 bar to a maximum of 2 000 bar and the new piezo injector concept with direct nozzle needle control Reduction of nitrogen oxides The combustion process has been optimized to sustainably reduce raw emissions by lowering the compression ratio from 16 5 1 to 16 2 1 significant improvements have been achieved espe cially with respect to nitrogen oxides The proportion of nitrogen oxides in the exhaust gas is lowered through exhaust gas recirculation s Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Emission reduction Thermal management Along with optimization of the warm up and cooling processes the n
43. ressure control For a better overview of how dual stage turbocharging works three different states of wide open throttle operation have been selected These states will be used to explain and illustrate the exact process The following boost pressure control states are described e Wide open throttle operation up to 1 200 rpm e Wide open throttle operation between 1 200 and 2 800 rpm Wide open throttle operation as of 2 800 rpm Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 dey ssed q asieyy dey ssed q dey ssed q 8129 289 52 Charging 00 SE2 OF 60d 94 Scl Vcl eci u unsn pe ajesajse 5 Q9YM euiqun JojJaduui JOSSAJAWOD J9pe T N 4e84euooqun aunssaJd M07 dejj o uoo eunssaJd 15008 Voci 0281 22 4 02 221 Jo41uoo 1500 211 12 01 2 55 1500 ILI 2 02 294M z 011 1 021 Jejjeduui JOSsaidwod 1 011 02 7 49S1CYIOGIN eunssa4d uSIH 011 oy ecb jSneux 801 8 18124 2091 98215 jeng Ebb CLL LLL 92 VOLL OLL C OLL 25 Introduction of
44. ssure turbocharger 8 Throttle valve actuator 13 EGR cooler 3 Boost pressure control flap LRK 9 Intake manifold 14 EGR bypass flap Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Charging Boost pressure control during wide open throttle operation between 1 200 and 2 800 rpm As of an engine speed of 1 200 rom during wide open Inthis state the two turbochargers work together and throttle operation the boost pressure control flap provide the required boost pressure jointly LRK is opened in the working range cross section of opening of 5 to 95 depending on the boost pres sure required As the cross section of the LRK opening increases the ND Lader is continuously engaged and a greater exhaust volume flows through it The intake of clean air is further pre compressed The wastegate and charge air bypass flap are closed in this operating condition 7 09 40 2349 00 Schematic illustration of boost pressure control during wide open throttle operation between 1 200 and 2 800 rpm A B Intake air 4 Wastegate 10 Exhaust manifold Exhaust flow 5 Charge air bypass flap 11 Exhaust gas recirculation EGR 6 Air filter pre cooler High pressure turbocharger Charge air cooler 12 EGR actuator Low pressure turbocharger 8 Throttle valve actuator 13 EGR cooler Boost pressure control flap LRK 9 Intake m
45. the CDI control unit is divided into the toring all system components and functions This following subtasks incorporates the following aspects e Engine torque control Fault memory checking e Injection control Engine control diagnosis Charging e European On Board Diagnosis EOBD Deceleration fuel shutoff Diagnosis CAN bus Thermal management Diagnosis via K line e Exhaust gas recirculation EGR e Exhaust treatment P15 00 2190 00 CDI control unit on air filter housing 1 CDI control unit 3 Air filter housing 2 Cooling fins 4 Air filter 42 gt Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Instant Start System The electronically controlled Instant Start System consists of a glow output stage and four ceramic glow plugs The Instant Start System allows the engine to be started immediately without preglowing at high coolant temperatures In order to improve the cold start and warm up characteristics of the engine after glowing is performed in steps via the controllable glow temperature The CDI control unit regulates the voltage at the glow plugs via the glow output stage depending on time and temperature This has the following advantages e Short preglow time e Stable idling e Low exhaust gas emissions Good response behavior Controllable glow temperature
46. transmission models Major assembly carrier with variable arrangement as per vehicle concept Two knock sensors e Two piece oil pan noise optimized Oil pan bottom section made of plastic i Note i Note Friction welded connections involve connecting Further information on repairing and maintaining two parts together by force The application of fric engine 651 can be found in the Workshop Informa tion and pressure produces a fixed connection tion System WIS without the use of welding consumable 8 Introduction of New Generation of 4 Cylinder Inline Engines OM 651 This printout will not be recorded by the update service Status 09 2008 Engine views P01 10 2973 Engine 651 Side view from left P01 10 2974 00 Engine 651 Side view from right Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt This printout will not be recorded by the update service Status 09 2008 Overview System comparison gt p 6 Comparison Engine 646 821EVO Engine 651 911 C 220 CDI C 250 CDI Market launch 06 2006 10 2008 Combustion system Diesel direct injection No of cylinders 4 Engine configuration Inline Bore mm 88 3 83 0 stroke mm 88 3 99 0 Compression ratio 16 5 1 16 2 1 Camshafts drive Duplex chain Simplex chain Camshafts number 2 2 Valve actuation Cup tappet Roller type cam follower with hydraulic valve with hydraulic valve clearance
47. uide pulley Belttensioner with tensioner pulley 9 Major assembly carrier Introduction of New Generation of 4 Cylinder Inline Engines OM 651 zz This printout will not be recorded by the update service Status 09 2008 19 Common rail injection Injection technology Engine 651 uses the new Common Rail technology of The most important new features of the injection the second generation from Delphi The maximum system include injection pressure has been increased by 400 bar to 2 000 bar A new feature is the piezo injector concept with direct nozzle needle control Direct actuation allows the injection volume to be changed quickly and with the utmost precision e High pressure pump with two pump elements max Injection pressure 2 000 bar e Electronic engine control with more advanced actuation function for injection timing points e Leak oil free injection system with piezo injectors The piezo injectors provide the following improve The increase in engine output to 150 kW 204 hp and ments the increase in engine torque to 500 Nm was only Greater flexibility for actuation of injection timing made possible by the increased pressure potential At points the same time the level of raw emissions produced by Lower fuel consumption the engine has been significantly improved Higher engine output Minimized combustion noise Reduced emissions Smoother engine running 20 Introduction of
48. urfold threaded connection Crank assembly with gear drive Connecting rods The weight optimized connecting rods are made of forged steel and are cracked at the level of the bearing shells Balance shafts Two Lanchester balance shafts are integrated in the main bearing bridge and mounted on three roller bear ings They are driven in opposite directions by the gear drive to counteract the inertia forces of the second order which are generated This ensures smooth engine running P03 20 2306 00 1 Oil and vacuum pump drive gear 5 Intermediate gears 8 Vibration damper 2 Crankshaft gear tensioning gears 9 Lanchester drive gears 3 Crankshaft 6 Piston 4 High pressure pump drive gear 7 Connecting rod i Note The aluminum pistons run in friction optimized cast iron cylinder barrels On this engine they are all manu factured uniformly There is therefore no differentiation between A B or X sizes on this engine Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt This printout will not be recorded by the update service Status 09 2008 15 16 Camshafts The gear drive drives the camshaft sprockets and the connected camshafts via a timing chain The mainte nance free timing chain is tried and tested and has proven longevity The cams are fixed to the camshaft by means of internal high pressure forming IHU Camshaft sprocket The camshaft sprocket is connected to the camsha
49. xhaust gas temperature P49 10 2871 00 We 4 Temperature sensor upstream of diesel particulate filter 5 Rear muffler If DPF regeneration is not possible during normal operation the engine diagnosis warning lamp lights up on the instrument cluster Introduction of New Generation of 4 Cylinder Inline Engines OM 651 gt This printout will not be recorded by the update service Status 09 2008 35 36 Engine cooling Engine lubrication and cooling circuit The coolant pump pumps coolant through two sepa rate ducts The lower duct supplies the crankcase and the oil water heat exchanger with coolant and the upper duct supplies the cylinder head with coolant The EGR path runs parallel to the upper duct The following components of the EGR path are supplied with coolant EGR valve e EGR bypass housing EGR pre cooler and EGR cooler Thermal management The coolant pump 15 switched off when the engine 15 cold started so that the combustion chamber can heat up more rapidly The coolant pump 15 switched off during a cold start for max 500 s if the following conditions are fulfilled e The limit values stored in the control unit for intake air and coolant temperature and for the total fuel injection quantity have not yet been reached he engine speed or injection quantity has not exceeded the specified limit value Heat has not been requested by the automatic air conditioning contro
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