BMW B46TU Reference Manual
  1. Manuals
  2. Brands
  3. BMW Manuals
  4. Engine
  5. B46TU
  6. Reference manual

BMW B46TU Reference Manual

Hide thumbs
Table of Contents

Advertisement

Quick Links

R e f e r e n c e Ma n u a l
B 4 6 T U / B 4 8 T U
E N G I N E S
T e c h n i c a l T r a i n i n g
T h e i n f o r ma t i o n c o n t a i n e d i n t h i s ma n u a l i s n o t t o b e r e s o l d , b a r t e r e d , c o p i e d o r t r a n s f e r r e d
w i t h o u t t h e e x p r e s s w r i t t e n c o n s e n t o f B MW o f N o r t h A me r i c a , L L C ( " B MW N A " ) .
C o p y r i g h t © 2 0 1 8 B MW o f N o r t h A me r i c a , L L C

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the B46TU and is the answer not in the manual?

Questions and answers

Related Manuals for BMW B46TU

Summary of Contents for BMW B46TU

  • Page 1 R e f e r e n c e Ma n u a l B 4 6 T U / B 4 8 T U E N G I N E S T e c h n i c a l T r a i n i n g T h e i n f o r ma t i o n c o n t a i n e d i n t h i s ma n u a l i s n o t t o b e r e s o l d , b a r t e r e d , c o p i e d o r t r a n s f e r r e d w i t h o u t t h e e x p r e s s w r i t t e n c o n s e n t o f B MW o f N o r t h A me r i c a , L L C ( "...
  • Page 2 Technical￿training. Product￿information. B46TU￿/￿B48TU￿Engines BMW￿Service...
  • Page 3 General￿information Symbols￿used The￿following￿symbol￿is￿used￿in￿this￿document￿to￿facilitate￿better￿comprehension￿or￿to￿draw￿attention to￿very￿important￿information: Contains￿important￿safety￿information￿and￿information￿that￿needs￿to￿be￿observed￿strictly￿in￿order￿to guarantee￿the￿smooth￿operation￿of￿the￿system. Information￿status:￿April￿2017 BMW￿Group￿vehicles￿meet￿the￿requirements￿of￿the￿highest￿safety￿and￿quality￿standards.￿Changes in￿requirements￿for￿environmental￿protection,￿customer￿benefits￿and￿design￿render￿necessary continuous￿development￿of￿systems￿and￿components.￿Consequently,￿there￿may￿be￿discrepancies between￿the￿contents￿of￿this￿document￿and￿the￿vehicles￿available￿in￿the￿training￿course. The￿information￿contained￿in￿the￿training￿course￿materials￿is￿solely￿intended￿for￿participants￿in￿this training￿course￿conducted￿by￿BMW￿Group￿Technical￿Training￿Centers,￿or￿BMW￿Group￿Contract Training￿Facilities. This￿training￿manual￿or￿any￿attached￿publication￿is￿not￿intended￿to￿be￿a￿complete￿and￿all￿inclusive source￿for￿repair￿and￿maintenance￿data.￿It￿is￿only￿part￿of￿a￿training￿information￿system￿designed￿to assure￿that￿uniform￿procedures￿and￿information￿are￿presented￿to￿all￿participants. For￿changes/additions￿to￿the￿technical￿data,￿repair￿procedures,￿please￿refer￿to￿the￿current￿information issued￿by￿BMW￿of￿North￿America,￿LLC,￿Technical￿Service￿Department. This￿information￿is￿available￿by￿accessing￿TIS￿at￿www.bmwcenternet.com. Additional￿sources￿of￿information Further￿information￿on￿the￿individual￿topics￿can￿be￿found￿in￿the￿following: • Owner's￿Handbook • Integrated￿Service￿Technical￿Application • Aftersales￿Information￿Research￿(AIR) The￿information￿contained￿in￿this￿manual￿is￿not￿to￿be￿resold,￿bartered,￿copied,￿or￿transferred without￿the￿express￿written￿consent￿of￿BMW￿of￿North￿America,￿LLC￿(“BMW￿NA”). ©2018￿BMW￿of￿North￿America,￿LLC The￿BMW￿name￿and￿logo￿are￿registered￿trademarks.￿All￿rights￿reserved.
  • Page 4 B46TU￿/￿B48TU￿Engines Contents Introduction ................................................1.1. Innovations￿B46TU ......................................1.2. Innovations￿B48TU ......................................1.3. Engine￿identification ......................................1.3.1. B46TU￿engine ................................... 1.4. Technical￿data ..........................................1.4.1. Model￿overview ..................................Engine￿Mechanical ............................................. 2.1. Engine￿housing ......................................... 2.1.1. Cylinder￿head ....................................2.2. Crankshaft￿drive ........................................2.2.1. Crankshaft ......................................2.2.2. Connecting￿rod ..................................2.2.3.
  • Page 6 B46TU￿/￿B48TU￿Engines 1.￿Introduction This￿document￿exclusively￿describes￿the￿changes￿to￿the￿B46￿and￿B48￿engine.￿The￿B46TU￿engine￿will be￿available￿in￿the￿new￿G20￿3￿Series￿and￿G29￿Z4￿Roadster￿in￿early￿2019.￿The￿B48TU￿engine￿will￿be available￿starting￿in￿November￿2018￿exclusively￿in￿the￿F39￿X2￿M35i. 1.1.￿Innovations￿B46TU To￿meet￿the￿legal￿requirements￿for￿emissions,￿a￿number￿of￿technical￿improvements￿have￿been implemented.￿The￿technical￿updates￿for￿the￿B46TU￿engine￿include￿the￿following￿new￿features: New￿features...
  • Page 7 B46TU￿/￿B48TU￿Engines 1.￿Introduction Index Explanation Modified￿cylinder￿head Crankshaft￿weight￿reductions Single-part￿timing￿chain￿drive Modified￿belt￿guide Split￿cooling Heat￿management￿module￿with￿electrical￿Split￿Cooling￿Valve￿(SCV) Fuel￿preparation￿with￿350 bar￿(5076￿psi)￿injection￿pressure DME￿8 Weight￿savings￿in￿the￿crankshaft￿drive￿area,￿injection￿pressure￿boosting￿in￿the￿fuel￿preparation￿area, and￿function￿changes￿in￿the￿engine￿cooling￿area￿have￿made￿it￿possible￿to￿reduce￿the￿CO ￿emissions￿by 2.5￿-￿5%,￿while￿increasing￿engine￿performance￿by￿5 kW/20 Nm￿(8￿hp/15￿lb-ft). 1.2.￿Innovations￿B48TU The￿technical￿improvements￿made￿to￿the￿B48TU￿engine￿a￿highlighted￿below: • 302￿hp￿(225￿kW) • 332￿lb-ft￿(450￿Nm) • Reinforced￿crankshaft￿with￿larger￿main￿bearing￿diameter. • New￿piston￿with￿modified￿compression. • New￿connecting￿rods￿without￿a￿bearing￿on￿small￿end. • Newly￿developed￿larger￿exhaust￿turbocharger￿with￿integrated￿air-diverter￿valve. • Modified￿fuel￿injectors￿with￿increased￿flow￿rate￿and￿350￿bar￿pressure. • Newly￿developed￿intake￿air￿pipes￿for￿higher￿power￿and￿torque. • Modified￿exhaust￿system￿to￿minimize￿back￿pressure. • Engine￿cover￿with￿M￿Performance￿logo.
  • Page 8 B46TU￿/￿B48TU￿Engines 1.￿Introduction 1.3.￿Engine￿identification 1.3.1.￿B46TU￿engine Engine￿identification—transverse￿mounted￿shown...
  • Page 9 B46TU￿/￿B48TU￿Engines 1.￿Introduction B48TU￿engine Engine￿identification—transverse￿mounted￿shown Index Explanation Engine￿number Engine￿identification The￿7-digit￿engine￿identification￿is￿located￿on￿the￿crankcase￿in￿the￿area￿of￿the￿mounting￿for￿the crankshaft￿alignment￿pin.￿The￿first￿6￿digits￿of￿the￿engine￿identification￿code.￿Only￿the￿seventh￿digit is￿different.￿The￿seventh￿digit￿of￿the￿engine￿identification￿code￿is￿the￿test￿number￿of￿the￿type￿approval certification. The￿4th￿digit￿in￿the￿engine￿identification￿shown￿above￿is￿an￿A,￿this￿represents￿its￿a￿transverse￿mounted engine￿that￿will￿be￿installed￿in￿the￿F39￿M35i.￿The￿G20￿and￿G29￿will￿have￿a￿B￿in￿the￿4th￿position￿that represents￿the￿engine￿is￿longitudinal￿mounted. The￿consecutive￿engine￿number￿is￿embossed￿above￿the￿engine￿identification.￿Using￿these￿two numbers￿the￿engine￿can￿be￿clearly￿identified￿by￿the￿manufacturer.
  • Page 10 B46TU￿/￿B48TU￿Engines 1.￿Introduction 1.4.￿Technical￿data The￿B46B20O1￿and￿B46B20T1￿engine￿is￿described: B46B20O1 B48B20T1 Power￿output￿in￿[kW￿(hp)] 190￿(255) 225￿(302) at￿[rpm] 5000–6500 5000–6250 Torque￿in￿[Nm￿(lb-ft)] 400￿(295) 450￿(332) at￿[rpm] 1550￿–￿4400 1750￿–￿4500 Number￿of￿cylinders Displacement￿in￿[cm³] 1998 1998 Bore￿/￿stroke￿in￿[mm] 82/94.6 82/94.6 Compression￿ratio 10.2￿:￿1 9.5￿:￿1 Valves￿per￿cylinder Start￿of￿Production￿(SOP) 11/2018 11/2018 1.4.1.￿Model￿overview The￿table￿below￿provides￿an￿overview￿of￿the￿models￿in￿which￿the￿new￿B46TU￿and￿B48TU￿engine￿is used. Models Engine G20￿330i B46B20O1 G29￿Z4 B46B20O1 F39￿X2￿M35i...
  • Page 11 B46TU￿/￿B48TU￿Engines 2.￿Engine￿Mechanical 2.1.￿Engine￿housing 2.1.1.￿Cylinder￿head The￿cylinder￿head￿is￿made￿of￿aluminum. Only￿slight￿modifications￿have￿been￿made￿to￿the￿B46TU￿head￿compared￿to￿the￿B46. Cylinder￿head...
  • Page 12 B46TU￿/￿B48TU￿Engines 2.￿Engine￿Mechanical 2.2.￿Crankshaft￿drive 2.2.1.￿Crankshaft Comparison￿B46￿crankshaft￿with￿B46TU￿crankshaft The￿crankshaft￿of￿the￿B46TU￿engine￿have￿been￿revised.￿Material￿adaptations￿have￿to￿both￿the counterweights￿and￿the￿connecting￿rod￿bearing￿journals￿have￿made￿it￿possible￿to￿achieve￿weight savings￿of￿up￿to￿1043 g￿(2.3￿lbs). A￿reinforced￿crankshaft￿with￿larger￿main￿bearing￿diameter￿is￿used￿in￿the￿B48A20T1￿engine. Comparison￿of￿crankshaft￿B46￿engine￿with￿B46TU￿engine Index Explanation Crankshaft￿of￿B46￿engine Crankshaft￿B46TU￿engine...
  • Page 13 B46TU￿/￿B48TU￿Engines 2.￿Engine￿Mechanical 2.2.2.￿Connecting￿rod Connecting￿rod Index Explanation Piston Area￿transferring￿the￿force Wrist￿pin Connecting￿rod￿bearing￿with￿shaped￿bore￿hole Connecting￿rod Connecting￿rod￿bearing￿(B46TU￿only) Small￿connecting￿rod￿eye￿(trapezoidal￿shape) Large￿connecting￿rod￿eye￿(cracked) Connecting￿rod￿bolts￿of￿the￿connecting￿rod￿bearing￿cap Connecting￿rod￿bearing￿shell￿of￿the￿connecting￿rod￿bearing￿cap Connecting￿rod￿bearing￿shell￿of￿the￿connecting￿rod￿(IROX-coated) The￿drop-forged￿cracked￿connecting￿rods￿with￿IROX￿coating￿are￿known￿from￿the￿B38/B46￿engines.
  • Page 14 B46TU￿/￿B48TU￿Engines 2.￿Engine￿Mechanical IROX￿coating Detailed￿magnification￿of￿the￿IROX￿coating Index Explanation IROX-coated￿bearing￿shell Oil￿film IROX￿coating Bearing￿shell Binding￿resin Hard￿particle Solid￿lubricant The￿IROX￿coating￿is￿applied￿to￿a￿conventional￿bearing￿shell.￿It￿consists￿of￿a￿binding￿resin￿matrix￿made of￿polyamide-imide￿with￿embedded￿hard￿particles￿and￿solid￿lubricants.￿The￿polyamide-imide￿ensures, in￿combination￿with￿the￿hard￿particles,￿that￿the￿bearing￿shell￿surface￿is￿so￿hard￿that￿material￿abrasion is￿no￿longer￿possible.￿The￿solid￿lubricants￿reduce￿surface￿friction￿and￿replace￿the￿oil￿film￿which￿briefly no￿longer￿exists￿between￿the￿bearing￿shell￿and￿the￿connecting￿rod￿bearing￿journal￿during￿the￿starting phase.￿The￿IROX￿bearings￿are￿red￿due￿to￿their￿special￿coating. The￿IROX-coated￿bearing￿shells￿are￿only￿located￿on￿the￿connecting￿rod￿side￿as￿here￿the￿load￿acts mainly￿on￿the￿bearing￿shells.￿The￿bearing￿shell￿caps￿are￿equipped￿with￿a￿bearing￿shell￿without￿IROX coating. If￿a￿connecting￿rod￿bearing￿cap￿is￿mounted￿the￿wrong￿way￿round￿or￿on￿another￿connecting￿rod,￿the fracture￿structure￿of￿both￿parts￿is￿destroyed￿and￿the￿connecting￿rod￿bearing￿cap￿is￿not￿centered.￿In￿this event￿the￿entire￿set￿of￿connecting￿rods￿must￿be￿replaced￿with￿new￿parts.￿In￿Service￿please￿observe￿the specified￿jointing￿torques￿and￿angle￿of￿rotation￿specifications￿in￿the￿repair￿instructions.
  • Page 15 B46TU￿/￿B48TU￿Engines 2.￿Engine￿Mechanical Bearing￿shell￿classification￿of￿connecting￿rod￿bearing The￿connecting￿rod￿bearing￿shells￿are￿available￿in￿one￿standard￿size.￿It￿is￿therefore￿not￿necessary￿to follow￿a￿procedure￿similar￿to￿that￿used￿with￿the￿main￿bearing￿shells￿of￿the￿crankshaft. 2.2.3.￿Chain￿drive Features: • Chain￿drive￿at￿the￿side￿of￿the￿engine￿emitting￿the￿forces. • Single-part￿chain￿drive￿for￿driving￿the￿camshafts. • Single￿sleeve-type￿chain￿8 mm. • Electric￿motor￿of￿the￿combined￿oil-vacuum￿pump￿via￿a￿separate￿chain. • Plastic￿tensioning￿and￿guide￿rail. • Hydraulic￿chain￿tensioner￿with￿spring￿preload￿and￿sealing￿sleeve. The￿following￿comparison￿shows￿the￿differences￿between￿the￿timing￿chain￿drive￿of￿the￿B46￿engine and￿that￿of￿the￿B46TU￿and￿B48TU engine:...
  • Page 16 B46TU￿/￿B48TU￿Engines 2.￿Engine￿Mechanical Comparison￿chain￿drive￿B46￿engine￿with￿B46TU Index Explanation Two-part￿chain￿drive￿B46￿engine Single-part￿chain￿drive￿B46TU￿and￿B48TU￿engine Slide￿rail Top￿timing￿chain Chain￿tensioner Tensioning￿rail Bottom￿timing￿chain Camshaft￿sprocket,￿oil/vacuum￿pump Drive￿chain￿oil/vacuum￿pump Guide￿rail Timing￿chain...
  • Page 17 B46TU￿/￿B48TU￿Engines 2.￿Engine￿Mechanical The￿main￿difference￿between￿the￿chain￿drive￿compared￿with￿the￿B46￿engine￿is￿the￿move￿from￿a￿two- part￿timing￿chain￿drive￿to￿a￿single-part￿timing￿chain￿drive.￿The￿timing￿chain￿direly￿drives￿the￿camshaft sprockets￿on￿the￿camshafts.￿Deflection￿via￿the￿intermediate￿shaft￿on￿the￿top￿timing￿chain￿and￿the second￿timing￿chain￿is￿no￿longer￿needed.￿The￿chains￿used￿here￿are￿8 mm￿sleeve-type￿chains.￿Because the￿intermediate￿gearing￿is￿no￿longer￿needed,￿the￿number￿of￿teeth￿on￿the￿crankshaft￿(23 teeth)￿and￿the VANOS￿unit￿(46 teeth)￿has￿also￿changed. Comparison￿chain￿track,￿B38￿and￿B38TU￿engines￿shown Index Explanation Chain￿track￿two-part￿timing￿chain￿drive￿(B38￿engine￿shown,￿￿B46￿is￿identical) Chain￿track￿single-part￿timing￿chain￿drive￿(B38TU￿engine￿shown,￿￿B46TU￿and B48TU￿are￿identical) B38￿&￿B38TU￿engines￿shown Upper￿timing￿chain Timing￿chain Lower￿timing￿chain Drive￿chain￿oil/vacuum￿pump The￿way￿the￿combined￿oil/vacuum￿pump￿is￿driven￿by￿a￿separate￿drive￿chain￿from￿the￿crankshaft￿has not￿changed.￿Only￿the￿renewal￿of￿the￿chain￿tracks￿has￿changed;￿the￿drive￿chain￿for￿the￿oil/vacuum pump￿is￿now￿located￿in￿front￿of￿the￿timing￿chain.
  • Page 18 B46TU￿/￿B48TU￿Engines 2.￿Engine￿Mechanical Eliminating￿the￿second￿timing￿chain￿offers￿the￿following￿benefits: • Improved￿acoustics • Lower￿space￿requirement • Reduced￿weight Chain￿tensioner Chain￿tensioner Index Explanation Tensioning￿rail Sealing￿sleeve Chain￿tensioner￿with￿screw￿thread Due￿to￿the￿cylinder￿head￿manufacturing￿process,￿the￿chain￿tensioner￿now￿has￿a￿sealing￿sleeve￿with￿a height￿of￿12.5 mm￿instead￿of￿a￿sealing￿ring.
  • Page 19 B46TU￿/￿B48TU￿Engines 2.￿Engine￿Mechanical 2.3.￿Valve￿gear 2.3.1.￿VANOS VANOS￿unit￿B46￿engine￿and￿B46TU/B48TU￿engines Index Explanation VANOS￿B46￿engine VANOS￿B46TU￿and￿B48TU￿engine Following￿the￿changeover￿from￿a￿two-part￿chain￿drive￿to￿a￿single-part￿chain￿drive,￿the￿camshaft sprockets￿on￿the￿VANOS￿now￿have￿46￿teeth￿instead￿of￿the￿previous￿36￿teeth.￿To￿compensate￿for￿the additional￿weight￿of￿the￿larger￿camshaft￿sprockets,￿the￿adjuster￿was￿designed￿to￿be￿shorter￿and￿more compact.￿Additionally,￿the￿chain￿track￿was￿displaced￿by￿1.5 mm.
  • Page 20 B46TU￿/￿B48TU￿Engines 2.￿Engine￿Mechanical 2.4.￿Belt￿drive Comparison￿belt￿drive￿B46￿engine￿and￿B46TU/B48TU￿engines Index Explanation B46￿Engine￿(transverse￿installation￿shown) B46TU/B48TU￿engines￿(transverse￿installation￿shown) Deflecting￿element Alternator Coolant￿pump Air￿conditioning￿compressor Ribbed belt Torsional￿vibration￿damper Belt￿tensioner The￿belt￿layout￿is￿a￿single-belt￿drive￿where￿all￿ancillary￿components￿are￿driven￿by￿one￿belt. Changing￿the￿belt￿guiding￿has￿help￿to￿save￿both￿material￿and￿space. The￿length￿of￿the￿drive￿belt￿changes￿due￿to￿thermal￿expansion￿and￿ageing.￿So￿the￿drive￿belt￿can transmit￿the￿required￿torque,￿it￿must￿be￿continuously￿in￿contact￿with￿the￿belt￿pulley￿at￿a￿defined pressure.￿To￿allow￿this￿to￿happen,￿the￿belt￿tension￿is￿exerted￿by￿an￿automatic￿tensioning￿pulley mounted￿on￿the￿alternator;￿the￿pulley￿compensates￿for￿belt￿elongation￿over￿the￿full￿service￿life.
  • Page 21 B46TU￿/￿B48TU￿Engines 2.￿Engine￿Mechanical In￿case￿of￿incorrect￿assembly￿of￿the￿drive￿belt,￿the￿coolant￿flow￿through￿the￿coolant￿pump￿is￿either insufficient￿or￿non-existent;￿there￿is￿thus￿a￿lack￿of￿cooling.￿There￿is￿a￿risk￿of￿damage￿to￿engine components￿and￿engine￿damage￿...
  • Page 22 B46TU￿/￿B48TU￿Engines 3.￿Cooling￿System 3.1.￿Split￿cooling Split￿cooling￿is￿a￿new￿development￿for￿the￿B46TU￿engine.￿This￿cooling￿concept￿is￿a￿modified￿version of￿which￿is￿already￿used￿in￿the￿N63TU2. The￿Split￿Cooling￿function￿uses￿the￿electrical￿Split￿Cooling￿Valve￿(SCV),￿to￿enable￿on-demand decoupling￿of￿the￿crankcase￿from￿the￿coolant￿flow￿both￿in￿the￿warm-up￿phase￿and￿in￿partial￿load operation.￿In￿this￿situation,￿the￿coolant￿is￿exclusively￿routed￿through￿the￿cylinder￿head.￿The￿engine reaches￿its￿operating￿temperature￿more￿quickly￿in￿the￿warm-up￿phase,￿and￿can￿be￿operated￿with reduced￿emissions￿in￿partial￿load￿operation. Coolant￿circuit...
  • Page 23 B46TU￿/￿B48TU￿Engines 3.￿Cooling￿System Index Explanation High￿cooling￿requirement,￿Split￿Cooling￿cylinder￿head Low￿cooling￿requirement,￿Split￿Cooling￿crankcase Cylinder￿head Crankcase Heat￿management￿module Split￿Cooling￿Valve￿(SCV) Coolant￿pump Cooling￿system￿overview...
  • Page 24 B46TU￿/￿B48TU￿Engines 3.￿Cooling￿System Index Explanation Radiator Coolant￿temperature￿sensor￿radiator￿outlet Additional￿coolant￿radiator Electric￿fan Split￿Cooling￿Valve￿(SCV) Coolant￿pump Bypass￿valve Engine￿block￿(crankcase) Coolant￿temperature￿sensor￿engine￿outlet Cylinder￿head Exhaust￿turbocharger Heater￿core Expansion￿tank Component￿temperature￿sensor Engine￿oil/coolant￿heat￿exchanger Transmission￿oil/coolant￿heat￿exchanger Heat￿management￿module Additional￿coolant￿radiator In￿Split￿Cooling,￿the￿cooling￿requirements￿for￿the￿crankcase￿and￿the￿cylinder￿head￿are￿managed￿by the￿electrical￿Split￿Cooling￿Valve￿(SCV).￿The￿fact￿that￿the￿engine￿reaches￿operating￿temperature￿more quickly￿again￿translates￿to￿substantial￿consumption￿and￿emission￿reductions. To￿guarantee￿optimal￿heat￿distribution￿during￿the￿cylinder￿head￿and￿crankcase￿warm-up,￿the￿coolant supply￿for￿the￿cylinder￿head￿and￿crankcase￿is￿controlled￿individually.￿Controlled￿by￿the￿Digital￿Motor Electronics￿(DME),￿the￿coolant￿is￿distributed￿by￿the￿electrical￿Split￿Cooling￿Valve￿(SCV)￿on￿the￿heat management￿module￿in￿the￿warm-up￿phase￿such￿that￿substantially￿more￿coolant￿is￿available￿to￿the cylinder￿head￿than￿to￿the￿crankcase.￿Depending￿on￿the￿engine's￿operating￿condition,￿the￿Digital￿Motor Electronics￿(DME)￿controls￿the￿distribution￿of￿the￿coolant￿quantity￿to￿the￿cylinder￿head￿and￿crankcase as￿required. A￿bleeding￿procedure￿must￿be￿carried￿out￿in￿accordance￿with￿the￿repair￿instructions￿and￿is￿required following￿a￿part￿exchange￿in￿the￿cooling￿system￿or￿refilling￿of￿the￿cooling￿system. A￿video￿demonstrating￿the￿bleeding￿procedure￿can￿be￿found￿in￿the￿B46TU￿Engine￿on-line￿course (OL1837). Filling￿without￿a￿vacuum￿filler￿device￿(watering￿can￿filling)￿is￿not￿approved￿￿There￿is￿a￿risk￿of￿engine damage￿in￿case￿of￿failure￿to￿comply￿￿The￿filling￿procedure￿must￿be￿observed￿ Operation￿of￿the￿vehicle￿is￿not￿permitted￿without￿completing￿the￿entire￿filling￿procedure￿sequence. There￿is￿a￿risk￿of￿functional￿limitations￿or￿overheating.
  • Page 25 B46TU￿/￿B48TU￿Engines 3.￿Cooling￿System 3.2.￿Heat￿management￿module The￿heat￿management￿module￿replaces￿the￿characteristic￿map￿thermostat. Heat￿management￿module Index Explanation Electrical￿Split￿Cooling￿Valve￿(SCV) Coolant￿output￿towards￿the￿coolant￿pump Electrical￿actuator Rotary￿valve A￿rotary￿valve￿inside￿the￿heat￿management￿module￿ensures￿needs-driven￿cooling￿of￿the￿various￿engine components.￿The￿opening￿cross-sections￿of￿the￿various￿coolant￿ducts￿can￿be￿opened￿or￿closed variably.￿A￿position￿sensor￿in￿the￿electrical￿actuator￿of￿the￿heat￿management￿module￿forwards￿the current￿position￿of￿the￿rotary￿valve￿to￿the￿Digital￿Motor￿Electronics￿(DME).￿The￿exact￿position￿of￿the rotary￿valve￿can￿thus￿be￿determined￿so￿that￿it￿opens￿or￿closes￿a￿precisely￿defined￿cross-section￿with respect￿to￿the￿various￿coolant￿ducts.￿Adjusting￿the￿cross-sections￿ideally￿adapts￿the￿flow￿rates￿of￿the coolant￿ducts￿connected￿to￿the￿heat￿management￿module￿to￿the￿engine￿operating￿points.￿To￿correctly position￿the￿rotary￿valve,￿the￿Digital￿Motor￿Electronics￿(DME)￿require￿information￿including￿the￿coolant temperature￿from￿the￿coolant￿temperature￿sensor,￿and￿the￿material￿temperature￿of￿the￿cylinder￿head from￿the￿component￿temperature￿sensor￿.Warm-up￿and￿cooling￿of￿the￿engine￿and￿the￿supply￿to ancillary￿components￿can￿be￿implemented￿as￿driven￿by￿requirements,￿thus￿optimizing￿consumption.
  • Page 26 B46TU￿/￿B48TU￿Engines 3.￿Cooling￿System 3.3.￿Operating￿strategy The￿following￿graphic￿shows￿the￿positions￿of￿the￿rotary￿valve￿as￿the￿coolant￿temperature￿increases: Switching￿diagram￿heat￿management￿module Index Explanation Rotary￿valve￿closed 100% Rotary￿valve￿open Cold￿start Warm-up￿phase Operating￿temperature Transition￿from￿normal￿operation￿to￿maximum￿cooling￿requirement Maximum￿cooling￿requirement Rotational￿angle￿in￿angular￿degrees Heater￿circuit Main￿coolant￿circuit Minor￿coolant￿circuit The￿openings￿on￿the￿rotary￿valve￿vary￿the￿cross-sections￿of￿the￿different￿coolant￿ducts￿as￿a￿function of￿the￿rotational￿angle￿of￿the￿rotary￿valve.￿The￿following￿graphics￿schematically￿represent￿the￿various engine￿operation￿phases,￿from￿cold￿start￿to￿maximum￿cooling￿requirement.
  • Page 27 B46TU￿/￿B48TU￿Engines 3.￿Cooling￿System 3.3.1.￿Cold-start￿phase Point￿A￿in￿the￿heat￿management￿module￿circuit￿diagram￿designates￿the￿cold￿start￿with￿an￿engine￿that has￿completely￿cooled￿down. Cold-start￿phase In￿the￿cold-start￿phase,￿the￿coolant￿circulates￿exclusively￿via￿a￿bypass￿in￿the￿coolant￿pump.￿The￿rotary valve￿in￿the￿heat￿management￿module￿closes￿the￿coolant￿lines￿so￿that￿the￿excess￿pressure￿that￿builds up￿opens￿the￿pressure￿relief￿valve￿in￿the￿coolant￿pump￿(opening￿pressure￿2.2 bar)￿and￿the￿coolant￿is recirculated￿in￿the￿coolant￿pump. Because￿the￿coolant￿circuits￿through￿the￿exhaust￿turbocharger￿and￿the￿ventilation￿line￿of￿the￿cylinder head￿cannot￿be￿closed,￿a￿low￿volumetric￿flow￿is￿returned￿to￿the￿coolant￿pump￿here.
  • Page 28 B46TU￿/￿B48TU￿Engines 3.￿Cooling￿System 3.3.2.￿Warm-up￿phase Area￿A￿in￿the￿circuit￿diagram￿for￿the￿heat￿management￿module￿shows￿the￿opening￿angle￿of￿the￿rotary valve￿in￿the￿warm-up￿phase. Warm-up￿phase In￿the￿warm-up￿phase,￿the￿heat￿management￿module￿additionally￿opens￿the￿connection￿to￿the￿heating in￿addition￿to￿opening￿the￿bypass￿line.￿The￿coolant￿flows￿through￿the￿cylinder￿head,￿the￿exhaust turbocharger￿and￿the￿engine￿oil/coolant￿heat￿exchanger.￿The￿electrical￿Split￿Cooling￿Valve￿is￿closed;￿no coolant￿flow￿through￿the￿engine￿block￿(Split￿Cooling).
  • Page 29 B46TU￿/￿B48TU￿Engines 3.￿Cooling￿System 3.3.3.￿Operating￿temperature The￿positions￿of￿the￿rotary￿valve￿at￿engine￿operating￿temperature￿are￿shown￿by￿area￿C￿of￿the￿heat management￿module￿circuit￿diagram. Operating￿temperature The￿graphic￿shows￿control￿with￿the￿engine￿at￿operating￿temperature.￿The￿position￿of￿the￿rotary￿valve means￿that￿the￿cross-sections￿of￿the￿respective￿coolant￿lines￿are￿open￿to￿a￿greater￿or￿lesser￿extent depending￿on￿the￿coolant￿temperature.￿The￿coolant￿flows￿with￿a￿varying￿volumetric￿flow￿through￿the small￿coolant￿circuit,￿the￿large￿coolant￿circuit￿and￿the￿heater￿circuit.￿Depending￿on￿the￿load￿request, the￿crankcase's￿coolant￿connection￿is￿opened￿by￿the￿electrical￿Split￿Cooling￿valve,￿thus￿cooling￿the crankcase.￿Large￿engine￿operation￿ranges￿are￿covered￿with￿the￿crankcase￿coolant￿circuit￿closed.
  • Page 30 B46TU￿/￿B48TU￿Engines 3.￿Cooling￿System 3.3.4.￿Maximum￿cooling￿requirement The￿maximum￿cooling￿requirement￿is￿shown￿at￿point￿E￿of￿the￿heat￿management￿module￿circuit diagram. Maximum￿cooling￿requirement To￿provide￿maximum￿cooling￿at￿high￿dynamic￿loads￿and/or￿high￿ambient￿temperatures,￿the￿radiator connection￿is￿fully￿opened￿(100%)￿and￿the￿bypass￿line￿is￿completely￿closed￿.￿Additionally,￿the￿heater circuit￿is￿90%￿closed￿to￿achieve￿the￿maximum￿cooling￿thanks￿to￿the￿maximum￿coolant￿volumetric￿flow through￿the￿large￿coolant￿circuit.
  • Page 31 B46TU￿/￿B48TU￿Engines 3.￿Cooling￿System 3.4.￿Coolant￿pump The￿layout￿and￿function￿of￿the￿coolant￿pump￿have￿been￿revised￿and￿adapted￿to￿match￿the￿cooling concept￿of￿the￿B46TU/B48TU engines. Coolant￿pump Index Explanation Pressure￿relief￿valve￿closed￿(pressure < 2.2 bar￿/￿32￿psi) Pressure￿relief￿valve￿opened￿(pressure > 2.2 bar￿/￿32￿psi) A￿pressure￿relief￿valve￿is￿installed￿in￿the￿mechanical￿coolant￿pump￿housing.￿In￿combination￿with￿the heat￿management￿module,￿the￿pressure￿relief￿valve￿on￿the￿one￿hand￿ensures￿that￿the￿engine￿operating temperature￿is￿reached￿more￿quickly,￿while￿at￿the￿same￿time￿reducing￿leaks￿and￿component￿damage due￿to￿high￿pressure￿in￿the￿cooling￿system. If￿an￿excess￿pressure￿of￿more￿than￿2.2 bar￿(32￿psi)￿builds￿up￿in￿the￿coolant￿circuit,￿the￿pressure￿relief valve￿opens￿and￿releases￿a￿bypass￿channel.￿The￿coolant￿is￿now￿exclusively￿circulated￿in￿the￿pump body.￿Once￿the￿pressure￿drops￿below￿2.2 bar￿(32￿psi),￿the￿pressure￿relief￿valve￿closes￿and￿the￿coolant is￿again￿routed￿through￿the￿coolant￿ducts.
  • Page 32 B46TU￿/￿B48TU￿Engines 4.￿Exhaust￿System 4.1.￿Exhaust￿turbocharger Exhaust￿turbocharger The￿exhaust￿turbocharger￿can￿be￿replaced￿individually￿and￿is￿exclusively￿made￿of￿steel.￿The￿boost charge￿pressure￿is￿still￿controlled￿by￿an￿electrical￿wastegate￿valve. The￿Turbo￿on￿the￿B46TU￿and￿B48TU￿are￿different￿in￿design.
  • Page 33 B46TU￿/￿B48TU￿Engines 5.￿Fuel￿System The￿fuel￿system￿is￿made￿up￿of￿the￿fuel￿supply￿and￿fuel￿preparation￿systems.￿The￿fuel￿supply￿includes the￿fuel￿tank￿with￿all￿mounted￿parts￿and￿the￿fuel￿lines￿up￿to￿the￿engine￿compartment. The￿fuel￿preparation￿system￿consists￿of￿the￿fuel￿filter￿lines￿in￿the￿engine￿compartment￿and￿all￿the￿fuel system￿parts￿on￿the￿engine. 5.1.￿Fuel￿preparation The￿fuel￿preparation￿has￿again￿been￿adapted￿to￿meet￿the￿emission￿legislation￿requirements.￿The￿high pressure￿pump￿and￿the￿injectors￿have￿been￿revised￿and￿designed￿for￿an￿fuel￿injection￿pressure￿of 350 bar￿(5076￿psi). Overview￿of￿fuel￿preparation Index Explanation Fuel￿delivery￿line Rail￿pressure￿sensor Direct￿rail Quantity￿control￿valve High￿pressure￿pump Solenoid￿valve￿injector Strict￿cleanliness￿must￿be￿observed￿when￿carrying￿out￿any￿work￿on￿the￿fuel￿system￿...
  • Page 34 B46TU￿/￿B48TU￿Engines 5.￿Fuel￿System 5.1.1.￿Fuel￿high-pressure￿pump The￿single-piston￿high￿pressure￿pump￿by￿Bosch,￿well-known￿from￿the￿B46￿engine,￿is￿used.￿The￿high pressure￿pump￿HDP6￿is￿driven￿by￿a￿triple￿cam￿which￿is￿attached￿to￿the￿exhaust￿camshaft.￿To￿be￿able to￿accommodate￿a￿fuel￿system￿pressure￿of￿350 bar￿(5076￿psi),￿the￿pump￿piston￿and￿tappet￿have￿been modified. Low￿pressure￿fuel￿is￿supplied￿to￿the￿high￿pressure￿pump￿via￿the￿in￿tank￿electric￿fuel￿pump. Bosch￿high-pressure￿pump￿HDP6 Index Explanation Low-pressure￿connection High-pressure￿connection Balancing￿chamber High-pressure￿non-return￿valve Pressure-limiting￿valve Pump￿piston Fuel￿fuel￿quantity￿control￿valve Electrical￿connection￿of￿fuel￿quantity￿control￿valve The￿fuel￿quantity￿control￿valve￿at￿the￿high￿pressure￿pump￿adjusts￿the￿fuel￿pressure￿in￿the￿rail.￿The maximum￿pressure￿in￿the￿rail￿is￿350 bar￿(5076￿psi);￿it￿is￿kept￿throughout￿the￿engine's￿entire￿operating range.￿The￿fuel￿pressure￿is￿only￿reduced￿to￿150 bar￿(2175￿psi)￿during￿idling.￿The￿high￿pressure￿pump contains￿a￿pressure￿limiting￿valve￿which￿opens￿at￿a￿pressure￿of￿400￿bar￿(5801￿psi).￿The￿fuel￿quantity control￿valve￿is￿activated￿via￿a￿Pulse-Width-Modulated￿(PWM)￿signal￿and￿assumes￿the￿open￿position￿in the￿de-energized￿state.￿This￿means￿the￿pump￿piston￿of￿the￿high￿pressure￿pump￿cannot￿compress￿the fuel.
  • Page 35 B46TU￿/￿B48TU￿Engines 5.￿Fuel￿System The￿high￿pressure￿pump￿in￿the￿high-pressure￿fuel￿system￿cannot￿build￿up￿pressure￿if￿the￿fuel￿quantity control￿valve￿is￿pulled￿off.￿In￿this￿situation,￿the￿maximum￿low￿fuel￿pressure￿of￿5.8￿bar￿(84￿psi)￿would be￿present￿in￿the￿rail￿during￿an￿engine￿start.￿The￿system￿would￿be￿in￿emergency￿operation.￿To￿ensure the￿engine￿remains￿capable￿of￿running￿in￿this￿state,￿the￿opening￿period￿of￿the￿solenoid￿valve￿injectors has￿been￿extended￿and￿the￿idle￿speed￿increased.￿Although￿the￿vehicle￿remains￿drivable,￿the￿maximum engine￿performance￿is￿not￿available. Due￿to￿the￿high￿fuel￿pressures,￿the￿fuel￿lines￿must￿never￿be￿detached￿when￿the￿engine￿is￿in￿operation. When￿removing￿the￿high￿pressure￿pump,￿follow￿the￿specifications￿in￿the￿current￿repair￿instructions. Excessive￿tilting￿of￿the￿pump￿can￿damage￿the￿pump￿piston￿ 5.1.2.￿Direct￿rail Injector￿mounting...
  • Page 36 B46TU￿/￿B48TU￿Engines 5.￿Fuel￿System Index Explanation Mounting￿bolts Plastic￿sleeve￿(not￿required￿to￿be￿reinstalled￿after￿taken￿apart￿for￿service) Holding￿clamp￿with￿bayonet￿fitting Rail Solenoid￿valve￿injector Casting￿lug The￿solenoid￿valve￿injectors￿are￿fastened￿to￿the￿holding￿clamp￿with￿a￿bayonet￿fitting.￿There￿is￿a￿plastic sleeve￿between￿the￿holding￿clamp￿and￿direct￿rail.￿This￿is￿not￿designed￿to￿collect￿escaping￿fuel.￿This is￿only￿used￿to￿support￿a￿helium￿leakage￿test￿during￿pre-assembly￿at￿the￿factory￿in￿order￿to￿check￿the tightness.￿After￿the￿initial￿assembly,￿this￿plastic￿sleeve￿is￿of￿no￿relevance￿to￿the￿engine￿operation.￿When the￿solenoid￿valve￿injectors￿are￿replaced,￿the￿plastic￿sleeves￿are￿no￿longer￿required￿and￿do￿not￿need￿to be￿reinserted. The￿mounting￿bolts￿of￿the￿holding￿clamp￿must￿be￿replaced￿each￿time￿they￿are￿released. The￿housing￿on￿the￿solenoid￿valve￿injectors￿is￿sensitive￿to￿excessive￿tensile￿forces￿and￿excessive rotational￿angles.￿When￿removing￿and￿installing￿the￿solenoid￿valve￿injectors,￿the￿procedure￿in￿the current￿repair￿instructions￿must￿be￿followed￿￿If￿the￿solenoid￿valve￿injectors￿are￿damaged,￿fuel￿may￿be discharged.
  • Page 37 B46TU￿/￿B48TU￿Engines 5.￿Fuel￿System 5.1.3.￿Solenoid￿valve￿injector Measures￿at￿the￿solenoid￿valve￿injector The￿following￿graphic￿illustrates￿the￿differences￿between￿the￿HDVE5￿and￿HDEV6￿fuel￿injectors: Solenoid￿valve￿injectors...
  • Page 38 B46TU￿/￿B48TU￿Engines 5.￿Fuel￿System Index Explanation Solenoid￿valve￿injector￿HDEV5 Solenoid￿valve￿injector￿HDEV5￿EVO Solenoid￿valve￿injector￿HDEV6￿(B46TU￿engine) Injector￿seat Injection￿pattern￿and￿volumetric￿distribution The￿new￿B46TU￿engine￿uses￿a￿solenoid￿valve￿injector￿HDEV6￿by￿Bosch.￿Due￿to￿the￿more￿stringent exhaust￿gas￿emission￿regulations￿required￿to￿meet￿the￿exhaust￿emission￿standards,￿technical￿changes were￿again￿made￿to￿the￿solenoid￿valve￿injectors.￿Sorted￿fuel￿injectors￿are￿used.￿This￿means￿that￿they are￿hand￿selected￿at￿the￿factory￿and￿tested￿for￿the￿least￿amount￿of￿fuel￿leakage. The￿solenoid￿valve￿injectors￿HDEV5￿and￿HDEV5￿EVO￿are￿used￿in￿the￿B46￿engine.￿While￿keeping￿the fuel￿system￿pressure￿of￿200 bar￿(2900￿psi)￿(HDEV5￿to￿HDEV5￿EVO),￿a￿reduction￿in￿pollutant￿emission was￿achieved￿by￿changing￿the￿injection￿pattern￿and￿volumetric￿distribution. Due￿to￿the￿fuel￿system￿pressure￿increase￿from￿200 bar￿(2900￿psi)￿to￿350 bar￿(5076￿psi),￿the￿solenoid valve￿injectors￿HEDV6￿were￿optimized￿using￿suitable￿materials￿and￿coatings.￿The￿injection￿pattern￿and volumetric￿distribution￿have￿not￿changed￿compared￿with￿the￿HDEV5￿EVO. The￿repair￿instructions￿that￿are￿currently￿valid￿must￿be￿carefully￿followed￿when￿removing￿and installing￿the￿injectors￿in￿Service.￿An￿excessive￿rotational￿angle￿at￿the￿injector￿shank,￿and￿excessive tensile￿and￿compression￿forces￿during￿removal￿and￿installation￿can￿lead￿to￿damage￿and￿therefore￿leaks in￿the￿fuel￿system.
  • Page 39 B46TU￿/￿B48TU￿Engines 6.￿Engine￿Electrical￿System 6.1.￿Digital￿Motor￿Electronics￿(DME) DME￿8￿control￿unit The￿Digital￿Motor￿Electronics￿(DME)￿is￿the￿computing￿and￿switching￿center.￿Sensors￿on￿the￿engine and￿the￿vehicle￿deliver￿the￿input￿signals￿and￿actuators￿implement￿the￿commands.￿The￿Digital￿Motor Electronics￿(DME)￿calculates￿the￿corresponding￿activation￿signals￿for￿the￿actuators￿from￿the￿input signals,￿and￿also￿the￿computing￿models￿and￿characteristic￿maps￿stored. The￿operating￿voltage￿range￿of￿the￿Digital￿Engine￿Electronics￿(DME)￿is￿between￿6￿and￿16 volts. An￿ambient￿pressure￿sensor￿and￿a￿temperature￿sensor￿are￿integrated￿in￿the￿Digital￿Motor￿Electronics (DME). The￿ambient￿pressure￿sensor￿permits￿precise￿determination￿of￿the￿density￿of￿the￿ambient￿air.￿This information￿is￿required￿for￿various￿diagnostic￿functions.￿In￿addition,￿in￿the￿event￿of￿a￿failure￿of￿the￿hot film￿air￿mass￿meter,￿a￿precise￿substitute￿value￿can￿be￿calculated￿for￿the￿cylinder￿filling￿with￿the￿help￿of additional￿input￿variables. The￿temperature￿sensor￿measures￿the￿temperature￿inside￿the￿control￿unit.￿If￿the￿temperature￿there rises￿too￿sharply,￿multiple￿fuel￿injection￿is￿reduced￿for￿example,￿in￿order￿to￿cool￿the￿output￿stages slightly￿and￿to￿keep￿the￿temperature￿inside￿the￿control￿unit￿in￿a￿non-critical￿range. The￿B46TU￿engine￿will￿have￿the￿DME￿8￿engine￿electronics￿generation.￿Depending￿on￿the￿engine version,￿the￿Digital￿Motor￿Electronics￿(DME)￿will￿be￿given￿a￿specific￿designation. DME￿8.x.y.z￿(x￿=￿number￿of￿cylinders,￿y￿=￿vehicle￿electric￿system￿architecture,￿z￿=￿H￿(hybrid))￿can￿be decoded￿as￿follows: • DME￿8.4.0￿=￿B46TU • DME￿8.6.0￿=￿B58 • DME￿8.8.0￿=￿N63TU2...
  • Page 41 Bayerische￿Motorenwerke￿Aktiengesellschaft Händlerqualifizierung￿und￿Training Röntgenstraße￿7 85716￿Unterschleißheim,￿Germany...

This manual is also suitable for:

B48tuB46b20o1B48b20t1

Table of Contents

Save PDF