BMW 745i Repair Instructions Download Page 1

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Summary of Contents for 745i

Page 1: ...BMW 745i TEST AND REPAIR INST RUCTIONS FOR SUPERCHARGED ENGINE Bayerische Mataren Werke AG Munich Service Division...

Page 2: ...theo retical knowledge they have acquired at our service training school Specifications are provided at the end of the brochure and apply to standard models which have not been involved in an accident...

Page 3: ...se in compression ratio will only produce a relatively small rise in pressure it is obviously better to optimize the cylinder charge This can be accomplished by precompression of the intake air The cy...

Page 4: ...nnec ted with the turbine 3 Charge air cooler Cools the charged air 4 Bypass valve For exhaust end control of the charge pressure 5 Air valve For control of charge pressure while coasting 6 Exhaust ma...

Page 5: ...I r 11 1 6 8 12 3 73000 117 7...

Page 6: ...r Intake neck 3 Exhaust gas turbocharger 4 Turbine 5 6 7 8 9 10 11 12 13 Compressor Charge air pipe Charge air cooler Charge air neck Air valve Exhaust manifold Bypass valve Exhaust pipe Exhaust bypas...

Page 7: ...cylinders The charge pressure must not exceed approx 0 7 bar 10 psi so that it must be controlled This is ac complished with the help of an exhaust gas bypass valve The compressor and bypass valve ar...

Page 8: ...1 3 2 Bypass Valve 6 i 1 Valve 2 Housing 3 Diaphragm springs 4 Spring 5 Control line conn 6 Heat shields 2 J 1 730 268 I 11...

Page 9: ...he ex haust gas turbocharger The high temperature of the air has two disadvantages a Heating the air will reduce its density and consequently the volumetric efficiency cylinder charge b The combustion...

Page 10: ...uts do not have to be tightened during all other inspections on the super charged engine Procedures Pull off multiple pin plug 1 Loosen hose clamp 2 and pull intake hose off of air flow sensor INSTALL...

Page 11: ...9 ft Ibs due to the length of the special ring wrench Tightening nut covered by the hydraulic unit Unscrew nuts on hydraulic unit INSTALLATION Tighten nuts to 22 25 Nm 16 18 ft Ibs Press hydraulic un...

Page 12: ...HOSES CAN CAUSE ENGINE DAMAGE OR A DROP IN POWER OUTPUT 2 3 Ignition Cables and Caps The ignition cables and caps employed on the supercharged engine are made of a high temperature resistant materiall...

Page 13: ...l angle at 1500 rpm 32 520 on distributor shaft and at _________ 7 3 0 1 2 0 27 4500 rpm 47 570 on distributor shaft Check dwell angle b Ignition Timing The ignition timing must be adjusted very accur...

Page 14: ...18 Connect vacuum pump 61 6 030 on the retarded box The aforementioned ignition timing must be mov ed 10 2 l toward retarded with a vacuum of 0 3 bar 4 2 psi...

Page 15: ...exhaust gas extraction system for duration of measurements to avoid incorrect data CO level at 850 50 rpm 0 5 2 0 by volume CO Level Too Low a Leak in intake system after air flow sensor b Throttle b...

Page 16: ...start aid does not switch off 13 62 050 d Function of fuel injection electric system check with tester 13 60 009 e Fuel injectors leak 1364501 Positions a e not cause of condition Remove cap 1 with a...

Page 17: ...portant to employ two persons for this test for safety s sake Connect pressure gauge 13 5 000 between the air valve and collector When testing on a dynamometer test stand connect the BMW service test...

Page 18: ...ance at a constant 80 km h 50 mph Note the charge pressure at 4000 4500 rpm Compare the measured value with the charge pressure graph The measured pressure must be within the specified tolerance range...

Page 19: ...TS a Checking Pressure Switch Pull off plug 1 Connect ohmmeter between both terminals Start engine Reading 00 ohms Detach hose on pressure switch Reading 0 08 ohms b Checking Speed Switch Connect t ac...

Page 20: ...at piston moves easily 1 Housing 2 Housing cover 3 Gasket 4 Spring 5 Piston 6 Seal Checking Pressure Switch Safety Switch Disconnect wire 1 Connect an ohmmeter between connection on pres sure switch a...

Page 21: ...MW 728 745 i workshop manual microfiche in carrier III and specifications microfiche for BMW 3 7 models in carrier II If no fault is indicated by internal test and calibration has been carried out cor...

Page 22: ...ensor adjust seal 8 Pressure sensor between injection pi pe and fuel line 9 Exhaust probe in exhaust external exhaust tester Ultramat 1 Bosch Siemens or Ultramat 11 1 HWB to analog input lead For comp...

Page 23: ...blower on car sequence 2 Connections diagnosis plug current clip 3 Switch on ignition at car s ignition switch Note coil off load current can be measured at lead between B and junction box with curre...

Page 24: ...ip trigger clip sequence 2 Start the engine e g with remote control Warning transmission must be in neutral 3 UD 13 5 V at 1500 min 4 I Battery 15 A bring in an electrical load e g by switching on hea...

Page 25: ...r sequence 2 If test step 02 was not carried out press until number of cylinders appears 3 Crank the engine until actual values appear app 6 8 s ignition drops for this period 4 Compare with the nomin...

Page 26: ...l values sequence 2 Values for individual cylinders are obtained with Repeat test step with print out Q Without print out Distributor No 0237304017 200 min I 20 0 C I 60 0 0 nominal values are not rea...

Page 27: ...s plug trigger clip 2 Start the engine 3 Compare with nominal values To repeat test step w ith print out ID Distributor No O rJ7 017 4500 5O min 78 3 94 9 47 57 dist shaft 2 0 V 3 0 crankshaft I If no...

Page 28: ...ger clip oil temp_ sensor exhaust probe TDC indicator sequence 2 Start the engine and detach vacuum hoses from the distributor 3 Program the engine speed window press Bl input nominal value 4 Slowly r...

Page 29: ...ngine and detach vacuum hoses from distributor Distributor No_ 0237304017 Imin o OS bTOC Ombar 3 Increase speed slowly to app 200 min above nominal values then return slowly to LL idle speed 4 Compare...

Page 30: ...istributor and throttle butterfly stub pipe 2 Input vacuum ADV start and end values To cancel input error 3 Detach retard vacuum hose from distributor and start engine 4 Slowly increase speed until pr...

Page 31: ...is plug trigger clip HT clip oil temperature sensor exhaust probe 2 Start the engine after firing voltage has appeared app 40 s Comp with nominal values 3 Press ill for individual cylinder values To r...

Page 32: ...7 850 50 min 40 mi n 60 C 0 5 2 0 by vol 2 3 2 7 bar I Exhaust temperature C r l Test sequence 1 Connections diagnosis plug trigger clip HT clip pressure sensor oil temp sensor ex haust probe exhaust...

Page 33: ...erature probe 2 Start the engine To start measurement press Compare nominal values after MINI MUM CYL display 3 Specific cylinder values are obtainable with ill Test completed repeat 111 for test step...

Page 34: ...crof iche into carrier III and specificaUons microfiche for BMW 3 7 models into carrier II I f the internal test does not indicate a fault and calibration has been carried out correctly tester not yet...

Page 35: ...the trigger clip is connected the number of cylinders will be automatically identified for test steps 01 and 02 4 Housing temperature of L Jetronic control unit 10 ___ 30 C other nominal values are qu...

Page 36: ...eeded T plug at wiring harness and control unit diagnosis plug pressure sequence sensor 2 Input number of cylinders with 3 Switch on ignition at car s ignition switch Note voltage between leads 10 and...

Page 37: ...ers with EJ unless test step 01 has just been carried out 3 Start the engine must go ouf 4 Increase engine speed to 4000 min then close OK throttle butterfly rapidly The text PULSE MISSING must appear...

Page 38: ...at wiring harness only ignition off 2 If IMPROPER CONNECTION is shown press 2 0 Q 999KQ 2 OQ 3 Move throttle butterfly slowly from idle to full load position until successive values appear I Note meas...

Page 39: ...ow meter pump switch resistance leads 10 and 20 2 0 Q I LMM airflow meter baffle resistance leads 7and9 _ 70 800 Q Test 1 Connections needed T plug only at wiring harness sequence 2 See Specifications...

Page 40: ...3 Q 2 2 3 3 Q I 2 2 3 3 Q 2 2 3 3 Q 2 2 3 3 Q 2 2 3 3 Q Test 1 Connections needed T plug at wiring harness only if necessary input number of cylin sequence ders 2 Compare with nominal values If nomina...

Page 41: ...93 ms 8 84 10 08 ms Test 1 Connections needed T plug at L Jetronic control unit only if necessary input number of sequence cylinders 2 Before starting measurement pre s 3 Measure L Jetronic control un...

Page 42: ...nnections needed T plug to L Jetronic control unit only if necessary input number of sequence cylinders 2 Voltage correction for 14 V to nominal ms value with then press 3 Correction values without no...

Page 43: ...ections needed T plug at L Jetronic control unit only it necessary input number ot cylinders 2 The measurement takes app 45 s 3 Correction values without nominal values can be disregarded 4 Compare wi...

Page 44: ...ot yet installed Contro l unit No 0280001124 ms s ms s I Test 1 Connections needed T plug at L Jetronic controll unit only if necessary input number of I sequence cylinders 2 The measurement takes app...

Page 45: ...pecifications microfiche into carrier It If the internal test does not indicate a fau lt and callibration has been correctly carried out tester not yet connected to car or to mechanica Jor electrical...

Page 46: ...plug at ABS wiring harness and ABS control unit 3 Test steps 01 07 can be performed without brake test dynamometer test steps 08 10 require the brake test dynamometer 4 Note correct test sequence for...

Page 47: ...etw leads 26 9 2114 and lead 10 999 k Q WS resistance to B R betw leads 26 9 21 4 and lead 1 999 k Q SIS safety lamp R betw leads 29 and 1 10 80 Q I Test 1 Connections needed T plug at ABS wiring harn...

Page 48: ...s 32 and 35 Valve RL rear left Resistance betw leads 32 and 18 Valve RR rear right Resistance betw leads 32 and 19 1 Test 1 Connections needed T plug at harness only sequence 2 Compare with nominal va...

Page 49: ...7 4 ms RR rear right 15 7 17 4 ms Test 1 Connections needed T plug at ASS harness and al ASS control unit Pulse 100 0 0 100 0 0 100 100 0 0 sequence 2 Raise car and turn wheels at steady speed within...

Page 50: ...w leads 14 and 1 1 0 V II SIS safety lamp diode voltage drop betw leads 29 and 32 0 3 1 6 V Test sequence 1 Connections needed T plug at ABS harness and ABS control unit 2 Switch on ignition 3 ABS tel...

Page 51: ...V 0 7 V 0 7 V 0 7 V 0 7 V 16 26 V passed passed Test 1 Connections needed T plug at ABS harness and ABS control unit sequence 2 Switch on ignition ABS telltale lamp must come on 3 Note voltage between...

Page 52: ...Switch on ignition note voltage between leads 1 and 10 10 8 V rear right 0 1 A 0 1 A 0 1 A 0 1 A 0 1 A 3 ABS telltale lamp goes out and pressure build up values appear app 4 s 4 Next press the key va...

Page 53: ...ion note voltage between leads 1 and 10 02651 00002 10 8 V rear ri ght c 0 1 A 4 5 5 7 A 1 9 2 3 A 4 5 5 7 A 1 9 2 3 A 3 ABS tel Uale lamp goes out and pressure build up values appear app 4 s 4 Next p...

Page 54: ...2 Front axle on brake dynamometer BPS and flashing on tester for FRONT L 3 Switch on ignition note voltage between leads 1 and 10 if necessary run engine at idle speed Switch on brake dynamometer for...

Page 55: ...it 2 With front axle on brake dynamometer and flashing on tester set to FRONT UR at rn 3 Switch on ignition Note voltage between leads 1 and 10 run engine at idle speed If neces sary Switch on brake d...

Page 56: ...e on brake dynamometer BPS and flashing on tester for REAR LlR with 3 Switch on ignition note voltage between leads 1 and 10 if necessary run engine at idle speed Switch on brake dynamometer for both...

Page 57: ...4 TROUBLESHOOTING SUPERCHARGED ENGINE 61...

Page 58: ...ect and tight fit on i bypass valve and compressor see notes in repair procedures for removing bypass valve on page 89 Diaphragm of bypass valve Replace bypass valve torn II Bypass valve seized does n...

Page 59: ...Check plug connection start relay to ballast resistor Wire from battery via ignition Excessive voltage loss lock to ignition coil term 16 eliminate Cold start aid Cold start relay cold start valve te...

Page 60: ...n throttle Correct setting specified value housing maladjusted Idle fluctuations Leak in intake system after Throttle housing air flow sen air flow sensor sor intake pipes hoses Oil dipstick fit not t...

Page 61: ...level incorrect I Correct CO level I Pressure regulator I Fuel pressure too low return line squeezed misrouted vacuum hose not connected Fuel filter Seriously clogged Air flow sensor Poor contact on s...

Page 62: ...nd turn off ignition prior to doing any work on a transistor ignition system DANGER Pull off black red wire from starter term 16 to 0 4 ohm resistor I _no Break in wire from starter to ballast Connect...

Page 63: ...Distributor 902 Ignition coil 903 Position sensor 904 Ballast rEtSistor 905 Transistor ignition control unit 906 Spark plugs 907 Alternator 908 Starter 911 Oil pressure switch 912 Oil level switch EXl...

Page 64: ...L 4 l 0 75W5 f C rt i t t O 7 5 WS H r 16SW ir _ _ _ fiOOO 0 75WS 1 l L r F 0 _ I I I I If 1 II j B 02 Q5CiOf _ _J B 11 0 Lfl a Jl 11 rn 1 I I 0 75BRGH g I I 1 I 1 1 075BRWS Lfl I 1 5 GNGE 0 75 I H r...

Page 65: ...REPAIR PROCEDURES r 73...

Page 66: ...pe upper 7 Charge air neck 8 Throttle housing 9 Air valve 10 Exhaust manifold front 11 Exhaust manifold rear 12 Collar 13 Flame shield ring 14 Seal 15 16 17 18 19 20 21 22 23 24 Flame shield ring Gas...

Page 67: ...JJ 21 7 B J...

Page 68: ...d install transmission 24 00 020 Detach power steering pump at rear Detach power steering pump at front Pressure hoses remain connected INSTALLATION Tighten drive belt which must give under thumb pres...

Page 69: ...ir pipe Hne Remove and install radiator 17 11 000 NOTE Disconnect oil lines Pipe remains connec ted on radiator 1 Feed line 2 Return line Disconnect positive and negative wires on battery Disconnect w...

Page 70: ...pin plug off of pressure switch Lift wires out of holders on wheel house Detach hose 4 INSTALLATION Check hose clamp and hose for correct fit Detach fuel return hose 6 and feed hose 7 Pull off vacuum...

Page 71: ...off wire 10 on ignition coil Take off cap 11 Disconnect wires 12 and 13 INSTALLATION Black wire 12 to term 1 Red black wire 13 to term 15 Detach wires on resistors RT SW red black GR green Unscrew bol...

Page 72: ...ull off mUltiple pin plug Disconnect connecting plug Pull out wire harness through hole toward engine compartment Detach ground wire Detach hose Attach engine hoist tackle 11 0 020 at front and rear D...

Page 73: ...71 Nm 49 51 ft Ibs 3rd step 75 81 NM 53 58 ft Ibs After installation run engine until it reaches oper ating temperature oil temperature at least 600 C I 140 F After warming up tighten cylinder head b...

Page 74: ...1 and hose for correct fit_ Take off heat shield_ INSTALLATION Give threads of bolts a light coat of copper paste HWB No 8122 9400 794 Detach bypass valve with flow element NOTE Use a 3 8 long 12 side...

Page 75: ...of staybolts a thin coat of copper paste HWB No 8122 9400 794 Tighten nuts to 25 28 Nm 18 to 20 ft Ibs IMPORTANT After driving car 1 000 km 600 miles exhaust manifold bolts must be tightened with 15 N...

Page 76: ...1270 1165 DISASSEMBLING ASSEMBLING EXHAUST MANIFOLD MANIFOLD REMOVED Unscrew ring nut with Special Tool 11 6 010 INSTALLATION 1 1 Ring nut 2 Seal 3 Heat shield rings 73011265 IMPORTANT Always replace...

Page 77: ...st manifolds and screw on ring nuts by hand Attach exhaust manifold on cylinder head INSTALLATION Give threads of ring nuts a light coat of copper paste HWB No 8122 9400 794 Tighten ring nuts to 200 2...

Page 78: ...crew bolts 2 and 3 INSTALLATION Check hose clamp 1 and hose for correct fit Replace gasket on flange 4 Detach oil line INSTALLATION Check gasket replacing if ne cessary Loosen hose clamp 4 and pull of...

Page 79: ...e Remove lockplates Unscrew bolts Remove exhaust gas turbocharger downward INSTALLATION Tighten bolts to 40 45 Nm 29 32 ft Ibs INSTALLATION Give threads of bolts a light coat of copper paste HWB No 81...

Page 80: ...9400 794 Tighten nuts to 20 25 Nm 15 to 18 ft Ibs Install control line without tension IMPORTANT Hold adapter with a wrench when detaching and attaching line Reinstall adapter with Loctite No 270 if...

Page 81: ...crew bolts INSTALLATION Replace gasket Tighten bolts to 9 11 Nm 6 5 to 8 ft Ibs 1165 REMOVING AND INSTAL LING CHARGE AIR COOLER Remove and install air cleaner 13 71 000 see page 95 Unscrew nut Loosen...

Page 82: ...dvanced vacuum box on distributor IMPORTANT Mount hose 3 with a hose clamp and check for correct fit Disconnect cables NOTE Push out nipple and disconnect cable at side of operating lever ADJUSTING a...

Page 83: ...clamp 2 and pun intake hose off of air flow sensor INSTALLATION Check intake hose and hose clamp for correct fit Unscrew bolts INSTALLATION Check gasket replacing if ne cessary Mount ground wire 3 aga...

Page 84: ...Pull off plug 1 Detach hose 2 Unscrew bolt 3 INSTALLATION Check hose clamp and hose for correct fit 1362 REPLACING PRESSURE SWITCH SAFETY SWITCH Disconnect wire 1 Loosen hose clamp 2 and pull hose of...

Page 85: ...Unscrew mounting bolts Push up injection tube until fuel injectors are moved out of guide in intake manifold Pull plug III off of fuel injector Take off circlip and pull fuel injector out of injec tio...

Page 86: ...r flow sensor INSTALLATION Check intake hose and hose clamp for correct fit Disconnect ground wire 5 on air flow sensor Take off housing cover with air flow sensor INSTALLATION Tighten bolt to 8 8 9 8...

Page 87: ...off hose INSTALLATION Check hose and hose clamp for correct fit Take off rubber cowl 9 Loosen clips for wire harness Loosen hose clamp 8 Remove air cleaner housing from above INSTALLATION Check hose...

Page 88: ...fuel pump and hold end in measuring glass 133020 INSTALLATION Use a new squeeze hose clamp Pull off plug on air flow sensor and connect termin als 36 and 39 Turn on ignition initial delivery pump run...

Page 89: ...uel level transmitter INSTALLATION Check seal replacing if neces sary INSTALLAliON Remove transport guard 21 on a new fuel level transmitter Unscrew initial delivery pump anticlockwise with 2 crossed...

Page 90: ...d Unscrew nuts INSTALLATION Give threads of staybolts a light coat of copper paste HWB No 8122 9400 794 Remove heat shield Unscrew nuts INSTALtATlON Check gaskets replacing if ne cessary Coat threads...

Page 91: ...eck retaining rings replacing if necessary lift out retaining rings Remove exhaust assembly INSTALLATION Check retaining rings replacing if necessary IMPORTANT Always cover the turbine after re moving...

Page 92: ...to the heating system in all driv ing conditions The vacuum pump is connected to the vacuum line for the heating system via a T adap ter Voltage is supplied via term_15 so that the vacuum pump runs w...

Page 93: ...ipl e material bearings Control pistons with rotation symetrical recess 0 045 0 014 mm 0 0018 0 0006 Hard chrome plated valve stems Made of high temperature proof material Nimonik Intake 46 mm 1 811 e...

Page 94: ...nsor Air valve 104 1st step 34 44 Nm 25 32 ft Ibs 2nd step 67 71 Nm 49 51 ft Ibs 3rd step 75 81 Nm 53 58 ft Ibs Torque angle 25 50 25 28 Nm 18 20 ft Ibs IMPORTANT Retighten with 15 Nm 11ft Ibs after 1...

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BMW 745i, Repair Instructions

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