SSP337 The 2.0l FSI engine with turbocharger - VolksPage.Net

Service TrainingSelf-study programme 337The 2.0l FSI engine with turbochargerDesign and function

The new FSI engines from Volkswagen do without stratified injection and place greater emphasis onoutput and torque. Until now, FSI direct injection was always associated with stratification. On theturbocharged engine, the abbreviation FSI remains but there is no stratified charge.Doing without fuel stratification and NOx sensors represents a loss on one part, but also promises thefinest driving enjoyment with high output and a torquey engine and great pulling power and economy.In this self-study programme you can familiarize yourself with the technical highlights of this engine.Further information can be found inself-study programme no. 322 -The 2.0l FSI engine with 4-valvetechnology.S337_002NEWWarningNoteThe self-study programme shows the designand function of new developments.The contents will not be updated.For instructions on testing, adjusting and repairs,please refer to the relevant service literature.2

At a glanceIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Engine mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Engine management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Test your knowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263

IntroductionDescription of the engineIn terms of basic dimensions and design, theturbo FSI engine is derived from the 2.0l FSI withengine code AXW.In order to meet the high expectations of aturbocharged engine, components of the enginehad to be adapted to specific requirements.The exhaust manifold and the turbocharger formone unit.The exhaust and turbo module is customerservice friendly and is attached to the cylinderhead by a clamping flange.Exhaust manifoldSolenoid valve forcharge pressurecontrolN75TurbochargerResonancesilencerTurbocharger airrecirculation valve N249S337_003The crankshaft mechanics have been adapted tothe higher demands of a turbocharged FSIengine.PistonConrodCrankshaftS337_0044

In order to meet the higher levels of power andheat transfer, the cylinder head has beenadapted to the specific conditions.The inlet camshaft features continuously variablevalve timing (adjustment range 42° crankshaftangle).Cylinder headInlet portsS337_005The optimised balancer shaft gear (AGW) isdriven by a decoupled drive chain sprocket.The function is similar to that of a dual massflywheel.Decoupled drive chainsprocketBalancer shaft gearS337_0065

Engine mechanicsTechnical dataThe 2.0l turbocharged FSI engine was first installed in the Audi A3 Sportback. At Volkswagen, the enginefinds its debut in the Golf GTI.Technical features- Turbocharger in exhaust manifold- Single pipe exhaust system with starter andunderbody catalyst close to engine- Hitachi high pressure pumpresistant to ethanol- Non-return fuel system- Homogenous fuel injectionTechnical dataEngine codeAXXEngine type4-cylinder in-lineengineCapacity [mm 3 ] 1984Bore [mm] 82.5Stroke [mm] 92.8Compression ratio 10.5:1Max. output147 kW at 5700 rpmMax. torque280 Nmat 1800-4700 rpmEngine management Bosch Motronic MED 9.1Variable valve timing 42° crankshaft angleExhaust gasrecirculationFuelExhaust gas treatmentEmissions standard EU 4Inner exhaustgas recirculationPremium unleadedRON 98 (normalunleaded RON 95 withreducedperformance)2 three-way catalyticconverterswith lambda controlTorque and performance graphTorque[Nm]S337_007Output[kW]Speed[rpm]S337_0086

The crankshaftThe component strength was adapted to thehigher combustion pressures.The contact faces of the main journals andconrod journals were made larger to improvestrength.Engine blockThe cylinder contact surfaces of the cast ironengine block were honed by means of liquidblasting.Liquid blasting and smooth honing are anextension of the familiar two-stage honingtechnique by two additional process stages. Inthe first new processing stage, any compacting ofthe bushing contact surface brought about fromthe high pressure procedure is removed, andscores and damage from honing and cracks fromalloying are rectified. The resulting surface isthereby largely free of metallic imperfections. Inthe final honing operation, the rough edgesarising from blasting and any remaining roughareas are smoothed out to the highest level.This type of honing shortens the running-in timeof the engine and leads to lower oil consumption.Contact facesS337_009S337_010Modified pistonsThe piston crown of the T-FSI has been adaptedto the homogenous combustion procedure.2.0l 4V FSI 2.0l 4V T-FSIS337_0117

Engine mechanicsThe balancer shaft gearThe balancer shaft gear was taken over from thecommon FSI engine. However, it had to bemodified as follows:CrankshaftDrive gearBalancer wheelsBalancer shafthousing●●●●●●Decoupled drive chain sprocket in balancershaft mechanismSeparation of splines and compensationweights to increase balancing efficiencyOil pump with greater gear widthPressure relief valve, controlled purely by oil,with oil control in vicinity ofoil pump, integrated in balancer shaft housingStrength optimised pressure cast housingBearings of balancer shaftslocated directly in aluminium housingSuction lineBalancershaftsDrive chain sprocketOil pumpS337_012The decoupled drive chain sprocketThe improved smooth running of the crankshaft in the lower speed range leads to a considerableincrease in chain forces in the balancer shaft gear. With a relative crankshaft vibration angle of 0.8° onthe normal FSI engine, the increased crankshaft vibration angle of 2° on the turbocharged FSI engine ismuch more noticeable. Due to the increased load of the chain drive, the chain would be subjected toincreased wear if there were no countermeasures. Therefore, there are curved springs in the hub of thechain sprocket. These decouple the input shaft of the balancer shaft gear to the crankshaft.Diamond washerHubFrictionbearingCurved springs(qty. 2)Chain sprocketFriction washerDished washerEnd washerS337_0138

The toothed belt drive mechanismAs with all 4-cylinder in-line engines of series 113,the valve timing is designed as a toothed beltand direct exhaust camshaft drive system.Due to considerably higher demands on thetoothed belt drive mechanism, such as:●●●higher valve spring forces due to turboturbo-specific timing in conjunction withadjustment range of 42° CA from continuouslyvariable valve timing (inlet camshaft).high pressure pump drive by means of3 cams on inlet camshaft,the toothed belt tensioning system, adopted fromthe naturally aspirated engine, was modified.This resulted in an elliptical toothed belt pulley onthe crankshaft.The CTC toothed belt pulley*, used for the firsttime, reduces rotational vibrations on thecamshaft and pulling forces on the toothed belt.FunctionThe positioning of the toothed belt on thecrankshaft is shown at TDC no. 1 cylinder, as inillustration 337_014. Once the working strokebegins, extremely high pulling forces areimparted on the toothed belt. These are reducedby the elliptical shape of the toothed belt pulley,due to the fact that the flat side of the pulleyallows slight detensioning of the toothed belt. Therotational vibrations that arise as a resultcounteract the rotational vibrations of the 2ndengine order in the resonance point of the timingmechanism, without causing excessive unrest inother speed ranges.* CTC toothed belt pulley = Crankshaft Torsionals CancellationS337_0149

Engine mechanicsThe cylinder headTurbo-specific changes were made to thecylinder head (with regards to the 2.0l FSI):●●●●Sodium filled exhaust valvesArmoured inlet and exhaust valve seatsStrength-optimised roller rocker fingers withreduction in web width from cams and rollersValve springs with increased spring forces(same valve springs for inlet and exhaustvalves)Furthermore, the inlet port geometry wasmodified. This enabled the tumble effect andthereby the knock resistance and smooth runningproperties to be improved.2.0l 4V FSI 2.0l 4V T-FSIS337_015S337_01610

The crankcase breather systemThe constant vacuum in the crankcase is assuredby a separate breather system for crankcase andcylinder head.The blow-by gases emerging from the crankcaseare passed via the primary oil separator in the oilfilter module to the cylinder head cover.When this happens, the blow-by gases aremixed with those from the cylinder head and arepassed through a labyrinth, where further oilseparation occurs.Since turbo operation requires more complicatedpressure control, there is a two-stage pressurerelief valve on the cylinder head cover, whichchannels the blow-by gases to the intakemanifold or turbocharger. When there is vacuumin the intake manifold, the blow-by gases are feddirectly to the intake manifold.In the case of charge pressure, a non-returnvalve closes in the pressure relief valve housing.The blow-by gases are fed to the turbochargervia a channel in the cylinder head cover. Torecognize an incorrectly installed pressure reliefvalve, a so-called diagnosis port has beenintegrated. Incorrect installation forcesunmetered air via the sealing area of thepressure relief valve into the cylinder head cover.The reaction of the lambda probe results indiagnosis of the unmetered air and a fault is thenstored in the memory.With charge pressure before turbochargerWith vacuum to intake manifoldGas outlet to turbochargerLabyrinth in cylinder head coverGas outlet tointakemanifoldPrimary oilseparatorOil filter moduleNon-return lockingvalvePressure reliefvalveDiagnosischannelNon-return lockingvalveS337_01711

Engine managementThe turbocharger/exhaust manifold moduleTo save space, an exhaust manifold/turbocharger housing was developed, which can be installed withall engine variations in longitudinal or transverse configuration. Importance was also placed on realisinga customer service orientated solution to allow the exhaust manifold to be removed and installed easily,and for a catalytic converter to be included close to the engine.Crankcase breatherconnectionCoolant flow to radiatorand from auxiliary waterpumpActive charcoal filterconnectionPressurised oil supplyTurbocharger airrecirculation valve N249Oil returnCoolant supply to engineblockS337_018The bearing of the turbine shaft is integrated in the compressor housing. The cylinder head cover housesthe crankcase and active charcoal breather connections. Screwed into the pressure connection is anindividually tuned resonance silencer to reduce the pressure pulsation noises.The required charge pressure is adjusted via the charge pressure control solenoid valve N75 (pressurerelief control as on 1.8 l turbocharged engine) and the so-called wastegate.The charge pressure control solenoid valve N75 and the turbocharger air recirculation valve N249 canbe found on the turbocharger.12

The turbocharger with new flange fixtureThe turbocharger module is easy to fit and is attached to the cylinder head by five threaded connections.For removal and installation, the clamping strip need not be loosened.The exhaust manifold is designed to take advantage of the firing order. The manifold is fluted to channelthe exhaust gases equally over the turbine. In this way, the exhaust ports are separated in line with thefiring order. Furthermore, the flute channel prevents the exhaust gas pressure from expanding into othercylinder ports.This means that the required turbine speed is maintained and the response of the turbocharger could beoptimised.Flute channelClamping stripS337_01913

Engine managementCharge pressure flow and charge pressure controlControl pressure is formed from the chargepressure and intake pressure via the energisedcharge pressure control solenoid valve N75. Thecontrol pressure affects the vacuum unit, whichactuates the wastegate valve via a linkage. Thewastegate valve opens a bypass channel toallow part of the exhaust gases past the turbineinto the exhaust gas system. This control featureallows the speed of the turbine to be controlledand the maximum charge pressure can therebybe regulated.If the control features fails, the vacuumunit is affected directly by the chargepressure, which imparts pressureagainst the spring. The maximumcharge pressure is thereby restricted toa basic operating charge pressure.Turbocharger air recirculation valve N249Charge pressure controlsolenoid valve N75WastegateVacuum unitCharge air coolerS337_02014

The electric overrun air recirculation control (previously pneumatic)In order to prevent the turbocharger from braking too heavily in overrun and between gear changes, anelectric turbocharger air recirculation valve N249 is installed.The electric overrun air recirculation control is much more durable than the pneumatic one.In overrun, the vacuum unit is completely closed. The overrun air recirculation control is open, evenbetween gear changes.During overrun, pressure is built up in the compressor housing due to the prevailing charge pressure. Thispressure build-up causes the compressor wheel to brake heavily, which leads to a reduction in theprevailing charge pressure (turbo drop). To prevent this from happening, the turbocharger airrecirculation valve N249 is opened by an electric servomotor. It opens a bypass channel to passcompressed air via the compressor wheel back to the suction side of the compressor circuit. This keepsthe turbine at a constant speed. When the throttle valve is opened, the turbocharger air recirculationvalve N249 is closed and charge pressure is immediately available again.OverrunAir intakefrom air cleanerUnder loadOverrun air recirculationvalve openOverrun airrecirculationvalveclosedS337_02715

Engine managementThe cooling system with coolant run-on pump and radiator run-onTo prevent oil deposits from burning onto the turbine shaft in the turbocharger, an auxiliary water pumpruns-on for up to 15 minutes after the engine has been switched off. It transports the cooler coolantagainst the direction of normal flow. As it does this, coolant drawn in from the auxiliary pump flows fromthe radiator via the turbocharger in the engine block and back to the radiator to break down the residualheat.Connection onturbochargerEngine block connectionAuxiliary water pump operationEngine operationEngine operationAuxiliary water pumpoperationRadiator outletAuxiliary water pumpRadiator inletS337_02116

The tumble flapsSince the engine is operated in homogenous mode, the tumble flaps are used to improve the internalmixture formation.At low loads, in a speed range from 1000 rpm to5000 rpm, the tumble flaps are closed:Torque[Nm]Output[kW]- to improve idling speed quality on acold engine- to increase the tumble effect and therebyimprove smooth running of the engine- in overrun to prevent engine joltsIn other speed ranges, the tumble flaps are opento avoid any resistance to flow and thereby areduction in performance.Range in which tumble flaps are closed.Speed[rpm]S337_022Tumble flap withsteel shaftCoupling rodThrottle valve moduleIntake manifold flap motorV157 with intake manifoldflap potentiometer G336S337_02317

Engine managementThe fuel supplyThe direct injection petrol engines are supplied with fuel via a demand-controlled fuel pump. Thisdemand-control feature was developed to bring the energy requirement of the fuel pump to a low leveland thereby to save fuel.To achieve increasingly high pressures, the pump is driven by 3 cams (2 cams on AXW).The electric fuel pump provides just the amount of fuel required by the engine at a prescribed systempressure. This is controlled by the engine control unit and an electronic system that regulates the speed ofthe fuel pump via pulse width modulation.Fuel pressure regulating valve N276High pressurefuel pumpPump cams (qty. 3)High pressure injectorLow pressure fuel circuitFuel pressuresender for lowpressure G410Pressure limitation valveHigh pressure fuel circuitFuel pressure sender G247S337_02418

Modes of operationThe turbocharged engine is driven in two modes of operation.Dual injection with cold startDual injection is a special mode of operation for rapid heating of the catalytic converter.To do this, a quantity of fuel is injected on the intake stroke at approx 300° before TDC of ignition. Thefuel distributes itself homogeneously due to the long gap before ignition. The second injection occurs atapprox. 60° before TDC of ignition in the compression phase.The rich mixture that thereby forms around the spark plug means that timing can be retarded to aconsiderable degree without affecting stability of the engine.Both injection periods result in lambda 1. Since the exhaust valves are already open, the exhaust gastemperature rises rapidly. This brings the catalytic converter to operating temperature (350°C) in a shortspace of time (30-40 seconds).When the driver door is opened, the electric fuel pump is energised by means of the door contact switch.The prestart serves as a means of shortening the start time and to build-up pressure more rapidly.A maximum counter is installed to prevent the pump from becoming damaged.Main mode of operation with catalytic converter at operating temperatureOnly homogenous injection occurs in the area of the spark plugs, as no additional heating of thecatalytic converter is necessary.The engine sets to lambda 1.To prevent heat bubbles forming in the fuel line, the electric fuel pump is actuated even when the engineis at operating temperature.19

Engine managementThe system overviewG70 Air mass meterG31 Charge pressure senderG42 Intake air temperature senderG28 Engine speed senderT16Diagnosis interfaceG40 Hall senderJ220 Motronic control unitJ338 Throttle valve moduleG187 Throttle valve drive anglesender 1 for EPCG188 Throttle valve drive anglesender 2 for EPCG79 Accelerator pedal position senderG185 Accelerator pedal position sender 2FF47Brake light switchBrake pedal switchG247 Fuel pressure senderG336 Intake manifold flap potentiometerG61 Knock sensor 1G66 Knock sensor 2G62 Coolant temperature senderG83Coolant temperature sender atradiator outletG410 Fuel pressure sender for low pressureG42 Intake air temperature senderG39 Lambda probeG130 Lambda probe after catalytic converterCOM leadCAN driveG476 Clutch position senderAlternator DFCCS on/offJ519J533Onboard supply ctrl unitDiagnosis interfacefor data bus20

J538Control unit forfuel pumpGG6Fuel gauge senderFuel system pressurisation pumpN30 - N33Injectors for cylinders no. 1 - 4N70 Ignition coil 1 with final output stageN127 Ignition coil 2 with final output stageN291 Ignition coil 3 with final output stageN292 Ignition coil 4 with final output stageJ338 Throttle valve moduleG186 Throttle valve drive for electronicpower controlJ317 Voltage supply relay term.30J757 Voltage supply relay forengine componentsJ329 Term. 15 voltage supply relayN80 Active charcoal relay solenoid valve 1N276 Fuel pressure control valveV157 Intake manifold flap motorJ285J527J104Control unit indash panel insertControl unit forsteering columnelectronicsControl unit forABSN205Inlet camshaft control valve 1N75Charge pressure control solenoid valveN249 Turbocharger air recirculation valveZ19Z29Lambda probe heatingLambda probe 1 heater aftercatalytic converterJ235 Coolant pump relayV50Coolant circulation pumpJ293 Radiator fan control unit (PWM)S337_02621

Engine managementFunctional diagramA BatteryF Brake light switchF47 Brake pedal switchG Fuel gauge senderG1 Fuel gaugeG6 Fuel pumpG28 Engine speed senderG31 Charge pressure senderG39 Lambda probeG40 Hall senderG42 Intake air temperature senderG61 Knock sensor 1G62 Coolant temperature senderG66 Knock sensor 2G70 Air mass meterG79 Accelerator pedal position senderG83 Coolant temperature sender at radiator outletG130 Lambda probe after catalytic converterG185 Accelerator pedal position sender 2G186 Throttle valve drive for electronicpower controlG187 Throttle valve drive angle sender 1 forelectronic power controlG188 Throttle valve drive angle sender 2 forelectronic power controlG247 Fuel pressure senderColour coding/keyOutput signalEarthInput signalPositiveCAN drive train22

G336 Intake manifold flap potentiometerG410 Fuel pressure sender for low pressureG476 Clutch position senderJ220 Motronic control unitJ235 Coolant pump relayJ285 Control unit in dash panel insertJ317 Term. 30 voltage supply relayJ329 Term. 15 voltage supply relayJ338 Throttle valve moduleJ519 Onboard supply control unitJ533 Data bus diagnosis interfaceJ538 Control unit for fuel pumpJ682 Term. 50 voltage supply relayJ757 Voltage supply relay for engine componentsN30 Injector for cylinder no. 1N31 Injector for cylinder no. 2N32 Injector for cylinder no. 3N33 Injector for cylinder no. 4S337_025N70 Ignition coil 1 with final output stageN75 Charge pressure control solenoid valveN80 Active charcoal filter system solenoid valve 1N127 Ignition coil 2 with final output stageN205 Inlet camshaft control valve 1N249 Turbocharger air recirculation valveN276 Fuel pressure control valveN291 Ignition coil 3 with final output stageN292 Ignition coil 4 with final output stageP Spark plug connectorQ Spark plugsS FuseT16 Diagnosis interfaceV50 Coolant circulation pumpV157 Intake manifold flap motorZ19 Lambda probe heatingZ29 Lambda probe 1 heater after catalytic converter23

ServiceSpecial toolsDesignation Tool ApplicationT10252Camshaft barTo lock camshaft in order toremove pulleyVAG 1687Charge air systemtesterTo check for leaks in charge airsystemWith new adapter1687/524

Special toolsDesignation Tool ApplicationT10133FSI special toolcaseCommon special tools for repairsto FSI engines. Also used onturbocharged FSI engine.T40057Oil drain adapterTo drain engine oil from oil filterhousingT40001PullerTo pull off camshaft pulleyT40001/1 - 7Arms for puller25

Test your knowledge1. In which mode of operation is the T-FSI driven? a) Homogeneous mode b) Homogeneous lean mode c) Stratified mode2. When are the tumble flaps actuated?3. Where is the elliptical CTC toothed belt pulley used? a) Variable valve timing b) Balancer shaft drive c) Toothed belt drive4. The flute channel in the exhaust manifold has the following tasks a) Equal flow of exhaust gases to turbocharger b) Prevents back flow of exhaust gases c) Turbocharger speed is maintained d) Response of turbocharger is optimisedAnswers:1. a 2. At low load in a speed range of 1000 - 5000 rpm3. c 4. a, b, c, d26

Notes27

337For internal use only © VOLKSWAGEN AG, WolfsburgAll rights reserved, including the right to make technical changes000.2811.52.20 Technical status 12/04❀ This paper was made fromchlorine-free pulp.