Tài Liệu Động Cơ Audi 2.0l TFSI Engines EA888 Series

Self Study Programme 645 For internal use only Audi 2.0l TFSI engines EA888 series Audi Service Training < Back The 4-cylinder TFSI engine by Audi represents the next evolutionary step forward, the basis being the third-generation engine The new engine is available with a displacement of litres and in 2 performance classes, one of which supersedes the previous 1.8l Gen.3 engine of performance class (125 kW to 147 kW) The aim of Audi’s designers was to reduce both CO2 and particulate emissions in line with statutory requirements The 2.0l Gen.3 BC engine shows that even fuel economy can be improved while increasing engine displacement The abbreviation "BC" stands for B cycle, a Miller combustion cycle which has now been refined by Audi Forward > Ξ Contents The engine modifications for both performance classes are identical with respect to the engine mechanicals, where a number of friction-reducing measures have been implemented There are differences as regards charge cycles and the combustion process The performance class engine operates on the Miller cycle, a patent dating from the year 1947 It was premiered in May 2015 at the Vienna Motor Symposium as the most efficient petrol engine in its class More than 10 years earlier, Audi put into production the first turbocharged, direct injection TFSI engine and, thus, with the aid of downsizing and downspeeding, set a milestone for "Vorsprung durch Technik" This SSP contains a QR code which you can use to access additional interactive content (refer to "Information on QR codes" on page 30) 645_002 Learning objectives of this self study programme: This self-study programmme describes the design and function of the 2.0l 4-cylinder TFSI engine from the EA888 Gen.3 MLBevo engine series with power outputs of 140 kW and 185 kW After you have completed this self study programme you will be able to answer the following questions: • What are the differences in terms of the engine mechanicals compared with the third-generation engines? • What are the new features of the lubrication, charging, fuel and injection systems? • How does the performance class engine differ from the performance class engine? • How does the Miller cycle work? Contents Introduction Objective Development of the engine series Presentation Specifications _ Third-generation MLBevo 2.0l TFSI engine Third-generation MLBevo BC (Audi ultra) 2.0l TFSI engine _ 10 Engine mechanicals Crankshaft drive _ 12 Engine block _ 14 Engine oil 0W-20 15 Cylinder head 16 Chain drive _ 18 Engine management Air mass meter 20 Combustion process 20 Miller cycle _ 21 New TFSI combustion process by Audi (B cycle) _ 22 Service 3-piece oil control rings 27 Scope of maintenance jobs _ 27 Appendix Glossary 28 Test your knowledge 29 Self study programmes _ 30 Information on QR codes _ 30 Notes _ 31 The self study programme teaches a basic understanding of the design and mode of operation of new models, new automotive components or new technologies It is not a repair manual! Figures are given for explanatory purposes only and refer to the data valid at the time of preparation of the SSP This content is not updated For further information about maintenance and repair work, always refer to the current technical literature In the glossary at the end of this self study programme you will find an explanation of all terms written in italics and indicated by an arrow ↗ Note Reference < Back Forward > Ξ Contents Introduction Objective By adopting a process known as rightsizing, Audi has, after downsizing, taken a further, decisive step forward Innovative engine technologies are selectively combined and configured in such a way that displacement, power output, torque, fuel consumption and operating conditions are optimally balanced The new engines have all the fuel economy advantages of a downsized unit in partial-load operation At higher engine loads, they draw on the benefits of the high-displacement engine This provides an optimal combination of efficiency and performance across the entire rev band For the first time, these engines are being used in the latest generation of the Audi A4 (type 8W) Audi also plans to employ these units in a number of Group vehicles in both longitudinal and transverse configurations The descriptions in this self study programme refer to the longitudinal engines in the Audi A4 (type 8W) at the start of production 645_003 Reference For further information about the first use of engines and the fuel system, please refer to Self Study Programme 644 "Audi A4 (type 8W)" < Back Forward > Ξ Contents Development of the engine series The EA113 or EA888 engine series has for many years been used in a number of Audi models and provides a broad basis for petrol engine configurations Development of this engine series was principally focused on improving fuel economy and reducing CO2 emissions Technology development Engine generation However, one of the engines from this series is also used in sporty models, such as the Audi S3 Below you will find a short summary of the various individual engine generations and their features EA888 3B 0/1 EA113 Year EA888 engine generation 0/1 3B 645_010 Key characteristics and features Further information • • • • • Self Study Programme 384 "The Audi 1.8l 4V TFSI engine with timing chain" Audi's first EA888 TFSI engine 1.8l and 2.0l variants Demand-controlled fuel system Camshaft drive via timing chain Variable valve timing on the exhaust side • On-demand oil delivery • Audi valvelift system (AVS) on the exhaust side • Secondary air system for SULEV engines Self Study Programme 436 "Modifications to the chain-driven 4-cylinder TFSI engine" • Exhaust manifold integrated in the cylinder head (IAGK) • Innovative thermal management (ITM) system with actuator for engine temperature control • Boost is provided by a turbocharger with electrical wastegate actuator • Dual injection system (MPI ↗ and FSI ↗) Self Study Programme 606 "Audi 1.8l and 2.0l series EA888 TFSI engines (third generation)" • New TFSI combustion process • Audi valvelift system (AVS) on the intake side • Supersedes the 1.8l variant ↗ Refer to "Glossary" on page 28 < Back Forward > Ξ Contents Presentation Specifications Performance class engine ↗ in the Audi A4 (type 8W)   Power output in kW   Torque in Nm   Power output in kW in efficiency mode 1)   Torque in Nm in efficiency mode1) Engine speed [rpm] 645_004 Features Specifications Engine code CVKB Type 4-cylinder inline engine Displacement in cm3 1984 Stroke in mm 92.8 Bore in mm 82.5 Number of valves per cylinder Firing order 1-3-4-2 Compression ratio 11.65 : 1 Power output in kW at rpm 140 at 4200 – 6000 In efficiency mode: 140 at 5300 – 60001) Torque in Nm at rpm 320 at 1450 – 4200 In efficiency mode: 250 at 1200 – 53001) Fuel type Premium unleaded 95 RON Engine management Bosch MED 17.1.10 Lambda/knock control Adaptive lambda control, adaptive knock control Mixture formation Sequential (dual) direct injection (FSI) and multipoint injection (MPI) with adaptive idle charge compensation Exhaust gas treatment Close-coupled ceramic calatyst, oxygen sensors before and after catalytic converter Emission standard EU 6 (W) CO2 emissions in g/km 1142)  or further information about switching to efficiency mode and the resultant changes in the power and torque curves, please refer to F page 24 2) Audi A4 Avant with front wheel drive and S tronic ↗ Refer to "Glossary" on page 28 1) < Back Forward > Ξ Contents Performance class engine ↗ in the Audi A4 (type 8W)   Power output in kW   Torque in Nm Engine speed [rpm] 645_011 Features Specifications Engine code CYRB Type 4-cylinder inline engine Displacement in cm3 1984 Stroke in mm 92.8 Bore in mm 82.5 Number of valves per cylinder Firing order 1-3-4-2 Compression ratio 9.6 : 1 Power output in kW at rpm 185 at 5000 - 6000 Torque in Nm at rpm 370 at 1600 - 4500 Fuel type Premium unleaded 95 RON Engine management SIMOS 18.4 Lambda/knock control Adaptive lambda control, adaptive knock control Mixture formation Sequential (dual) direct injection (FSI) and multipoint injection (MPI) with adaptive idle charge compensation Exhaust gas treatment Close-coupled ceramic calatyst, oxygen sensors before and after catalytic converter Emission standard EU 6 (W) CO2 emissions in g/km 1291) / 1392) Audi A4 saloon with front wheel drive and S tronic Audi A4 Avant with quattro drive and S tronic ↗ Refer to "Glossary" on page 28 1) 2) < Back Forward > Ξ Contents Third-generation MLBevo 2.0l TFSI engine (performance class 2) Below you will find a summary of the key differences compared with the third-generation 2.0l TFSI engine If the car is equipped with a start-stop system, a Version 2.0 system is generally used For more information about the versions of start-stop systems, please refer to Self Study Programme 630 "Audi TT (type FV)" Pistons • The piston has the same geometry as in the 165 kW basic engine • The piston is made from the same material as in the Audi S3 (type 8V) • 3-piece oil control ring 645_016 ACF system • Increased air flow • Noise reduction measures 645_015 Engine management • Simos 18.4 system • Throttle valve with reduced air leakage • The throttle valve and the high-pressure fuel pump are supplied by Bosch • Engine control unit interface to the FlexRay bus system 645_014 The basis for the third-generation MLBevo 2.0l TFSI engine is the 165 kW 2.0l TFSI engine from the Audi A4 (type 8K) (engine code CNCB) < Back Forward > Ξ Contents Oil supply • Modified to create space for the use of electromechanical steering (ESP) and the planned roll stabilisation system • A non-return valve in the oil filter module allows maximum oil pressure to be built up more quickly at all lubrication points, especially when the engine is cold There is no non-return valve in the engine block or in the cylinder head • Increasing the oil volume between minimum and maximum oil levels ensures that a sufficient volume of oil is available at the intake end of the oil pump whenever the driver adopts an especially dynamic driving style 645_017 Cylinder head • An alternative material is used to allow for higher power output and the resultant higher levels of thermal stress • The coolant jacket is now thicker • The valvegear has been modified, e.g by using sodium-filled exhaust valves, to allow for higher power output and the resultant higher levels of thermal stress • The exhaust turbocharger has been uprated for temperature stability up to 950 °C 645_018 Engine block • The ventilation system has been rerouted across the balancer shafts • The modifications to the positive crankcase ventilation system necessitate directional installation of the piston cooling jets (refer to workshop manual) 645_012 Modifications to ULEV 125 (USA) • No multi-point injection (MPI) • Diagnosable PCV system ventilation hose (mandatory) 645_019 < Back Third-generation MLBevo BC (Audi ultra) 2.0l TFSI engine (performance class 1) Below you will find a summary of the key differences compared with the third-generation MLBevo 2.0l TFSI engine with a power output of 185 kW Fuel system • Pressure increase to 250 bar • Adaptation of the components in the high-pressure system 645_021 Chain drive • Longer guides • Non-circular sprocket for timing drive • Chain tensioner with lower tensioning force • Faster oil pump gear ratios, sprocket with 22 teeth (previously 24 teeth) 645_029 Engine management • Bosch MED 17.1.10 system • New combustion process (BC = B cycle) • Use of an air mass meter for the new combustion process 645_020 10 Forward > Ξ Contents < Back Forward > Ξ Contents Chain drive The basic configuration of the chain drive has, to a large extent, been adopted from the third-generation engine However, it too has been systematically improved Due to the further reduction in friction loss, less power input is required to drive the chain drive Even more extensive modifications were made in the case of the performance class engine Below you will find a summary of the various individual modifications Chain guide The guide rail guides the chain between the two camshaft gears, during which, however, it has barely any contact with the chain To provide skip protection, the guide rail has been extended and is bolted onto the cylinder head cover Guide rail Upper skip guard Guide rail Lower skip guard Guide rail A skip guard is attached to both ends of the guide rail This precaution has already been incorporated into series production of the third-generation 2.0l TFSI engine 18 645_033 < Back Forward > Ξ Contents Balancer shaft drive The balancer shaft drive incorporates the following friction-reducing modifications • Narrower chain design and reduction in number of chain links from 96 to 94 • Layout with fewer deflections • New clamping rail and guide rails • New sprockets • Chain damper with softer damping Balancer shafts Timing drive gear Timing drive gear The special design of the cam contours on the camshafts produces forces within the timing drive The timing chain drive sprocket therefore has a non-circular shape, similar to that of a cloverleaf This reduces both chain forces and movement within the chain tensioner, allowing a more simple chain tensioner design to be realised (without a pressure reduction valve) Oil pump Oil pump drive The gear ratios have been modified in such a way that the oil pump now runs more quickly The sprocket now has 22 teeth instead of the previous 24 This modification was necessary to ensure that all lubrication points are reliably supplied with the new 0W-20 specification engine oil 19 < Back Forward > Ξ Contents Engine management Air mass meter The MED 17.1.10 engine management system by Bosch is used in the performance class engine In this system air intake is monitored by an air mass meter This is necessary because the throttle valve is, as far as possible, open during the active B cycle As a result, only a single air mass meter is needed to monitor the return flow 645_034 Combustion process For the first time in an Audi, the performance class engine utilises a new combustion process One of the primary objectives was to improve fuel economy This is essentially accomplished by shortening the compression phase In the early years of combustion engine development similar efforts were undertaken to improve the efficiency of petrol engines, resulting, for instance, in the Atkinson and Miller cycles Atkinson cycle As early as the year 1882 James Atkinson unveiled an engine designed to significantly increase the thermal efficiency of the internal combustion engine while circumventing patents on the four-stroke engine by Nicolaus August Otto In Atkinson's engine all four strokes are performed by a specially designed crank mechanism within a single crankshaft cycle The fact that the crankshaft must produce two upward movements of the pistons to achieve this allowed Atkinson to use pistons in different lengths He took advantage of this difference to create a shorter compression stroke and a longer expansion stroke (working stroke) The crank mechanism is designed in such a way that the compression ratio is smaller than the expansion ratio The piston travels less distance during the working and exhaust cycles than during the intake and compression cycles Intake valve closing is heavily retarded, i.e after BDC (bottom dead centre) during the compression stroke An advantage is that the higher expansion ratio increases efficiency The working stroke takes longer thereby minimising the amount of waste heat in the exhaust gases However, there is a drawback in that relatively little torque is available at low rpm The Atkinson engine needs to be running at a relatively high speed before it can reliably deliver power without any risk of stalling The Atkinson cycle is very difficult to implement on account of the complex crank mechanism geometry Piston at bottom dead centre (BDC) between intake and compression cycles Piston at bottom dead centre (BDC) between working and exhaust cycles Piston travel during the intake phase Piston travel during the working stroke 645_035 Scan the QR code to find out more about how the Atkinson cycle works 20 645_036 < Back Forward > Ξ Contents Miller cycle Another option for changing the compression and expansion ratios is the Miller cycle The inventor Ralph Miller took out a patent on this principle in 1947 His aim was to transfer the Atkinson cycle to conventional crankshaft engines and utilise the its beneficial effects while consciously dispensing with the Atkinson cycle's complex crank mechanism To date, the Miller cycle has mainly been used in the engines of several Asian vehicle manufacturers Basic principle A special valve gear control unit is used in engines which work on the Miller cycle principle In the intake stroke in particular, this has the following effects: • Less air intake Its primay function is to close the intake valves earlier than in a conventional petrol engine • Compression is roughly the same • Lower compression ratio • Higher expansion ratio Advantages Drawbacks • Varying the valve opening times, i.e by increasing the expansion ratio, allows throttle-free load control and therefore significantly increases efficiency • Less torque at low engine speeds This can, for example, be compensated by turbocharging • A lower compression ratio means fewer nitrous oxides in the exhaust gases • Lower efficiency due to the smaller effective compression ratio This can be compensated by turbocharging and charge air cooling • The charging temperature is lower • At least one camshaft phasing adjustment is required • Combustion is improved 21 < Back Forward > Ξ Contents New TFSI combustion process by Audi (B cycle) The new TFSI combustion process in the 2.0l TFSI engine of performance class is basically a modified Miller cycle This provides better fuel economy than the equivalent third-generation 1.8l TFSI engine, although friction within the engine is higher due to the larger engine displacement The valve opening times on the intake side are controlled by the Audi valvelift system (AVS) For this purpose, the AVS switches to a single piston which, firstly, provides alternate valve opening times (earlier closing of the intake valves) and, secondly, reduces the opening width of the intake valves This combustion process is known as a "combustion process with extended expansion phase" or "B cycle" Strictly speaking, it is not so much that the expansion phase is extended as that the compression phase is shorter The term "extended expansion phase" would only apply if one were to compare this combustion process with that of a low-displacement engine, which achieves a similar degree of fresh gas compression with a reduced overall stroke Comparison of the valve and piston positions At partial load At full throttle • • • • • • • • High basic compression Intake valve closes early Short valve opening times Very low exhaust emissions Less valve lift means reduced intake valve opening width The result is a smaller opening diameter Retarded intake valve closing Long valve opening time High torque High power output The full valve stroke allows normal intake valve opening The result is a larger opening diameter 645_042 645_043 Valve lift adjustment with Audi valvelift system (AVS) There are two cam contours for each valve on the cam elements The cam timings are adapted for the required engine characteristic This affects both valve opening length and time as well as valve lift (opening diameter) In the case of the short cam paths (highlighted in green in the adjacent diagram), valve opening length is 140° crank angle In the case of the full stroke with long cam paths (highlighted in red), valve opening length is 170° crank angle Different cam height, affecting valve lift 140° crank angle 170° crank angle 22 645_052 < Back Forward > Ξ Contents Characterisation The new TFSI combustion process by Audi is characterised by the following features: • Activation in the partial-load range of the engine • Shorter compression phase (similar to Miller cycle) • Expansion ratio is higher than compression ratio (similar to Miller cycle) • Higher geometric compression ratio • Modified combustion chamber design (masking, valve diameter, piston design) • Modified cylinder head intake port (to create swirl) Comparison of piston positions in the compression stroke They show the position of the piston at the intake closing point (hV = 1.0 mm) in a third-generation 2.0l TFSI engine compared with the third-generation 2.0l TFSI engine at an engine speed of 2000 rpm and at an effective mean pressure (pme) of 6 bar Third-generation 2.0l TFSI engine with conventional combustion process Third-generation 2.0l TFSI engine with new combustion process (B cycle) Piston travel during the intake phase This diagrams below shows the piston position at the intake closing point for the third-generation 2.0l TFSI engine using the conventional combustion process and the third-generation 2.0l TFSI engine using the new B cycle combustion process Intake valve closes at 20° crank angle in advance of BDC Intake valve closes at 70° crank angle in advance of BDC 645_041 Scan the QR code to find out more about the modifications to the cylinder head Scan the QR code to find out more about the modifications to the overall engine 23 < Back Forward > Ξ Contents Operating strategies Engine start The intake camshaft is in contact with the small cam, i.e short lift and short intake phase with 140° crank angle as well as short intake valve opening time Fuel is injected during the start phase in the compression stroke and/or intake stroke (single, multiple), depending on engine temperature Warm-up phase Fuel stratified injection (FSI) is carried out once or twice up to a coolant temperature of 70 °C The system will then switch to multipoint injection (MPI) depending on engine speed, load and temperature Engine running at normal operating temperature Depending on load demand in the B cycle or the full throttle map In the B cycle • The B cycle combustion process is active at idle and in the partial-load range • The intake camshaft is in contact with the small cam • Fuel is injected through the MPI injectors up to an engine speed of 3000 rpm in the low and partial-load ranges • The intake manifold flaps are only activated in the low-load range • The throttle valve is open as wide as possible • Charge pressure is increased (up to 2.2 bar absolute) This allows optimal charging of the cylinders with fresh gas during the short intake valve opening time Full throttle map • The intake camshaft is switched to full-throttle contour by the Audi valvelift system (AVS) A 170° crank angle intake phase is now implemented • The intake manifold flaps are open in the full throttle range • Depending on the characteristic map, FSI fuel injection is employed Up to injections are possible, depending on requirements The amount of fuel injected and the injection timings are variable • The throttle valve now switches to normal operating mode efficiency mode If the driver selects efficiency mode in Audi drive select, engine torque is reduced to 250 Nm by the engine control unit and a power output of 140 kW is achieved at only 5300 rpm Oil pump control steps Effective mean pressure [bar] 320 Nm 140 kW Low pressure setting High pressure setting Engine speed [rpm] 24 645_049 < Back Forward > Ξ Contents Injection and cooling system 320 Nm 140 kW Effective mean pressure [bar] FSI injection MPI injection 105 °C of coolant Engine speed [rpm] 645_050 Intake manifold flaps and Audi valvelift system (AVS) Effective mean pressure [bar] 320 Nm 140 kW AVS with short valve lift AVS with long valve lift Intake manifold flaps closed Engine speed [rpm] 645_051 Threshold for switching back from long to short valve lift 25 < Back Forward > Ξ Contents Processes inside the cylinder The conditions inside the combustion chamber are shown below in comparison with a conventional petrol engine Working stroke Intake The piston moves from TDC to BDC The intake closes well in advance of BDC After the intake valve closes, the pressure inside the cylinder drops because the piston is still moving downwards Compression The piston moves from BDC to TDC The decrease in pressure first has to be equalised The pressure is again equalised with the pressure in the intake stroke at 70° crank angle in advance of TDC In a conventional combustion process the pressure is already higher at this stage The new combustion process allows a faster pressure increase due to the higher geometric compression ratio The pressure at TDC is roughly equal (approx 12 bar) Overall, the new combustion process has a higher mean pressure level and, therefore, higher efficiency Start of working cycle The piston moves from TDC to BDC In the new combustion process the pressure level is higher during the expansion phase due to the lower combustion chamber volume Exhaust The piston moves from BDC to TDC The new combustion process brings a small gain in efficiency due to differences in air/fuel mixture mass and heat transfer 26 Conventional combustion process New combustion process (BC = B cycle) < Back Forward > Ξ Contents Service 3-piece oil control rings The 3-piece oil control rings conists of thin steel plates as well as a spacer and expander spring This spring presses the steel plates (oil control rings) against the cylinder wall The 3-piece oil control rings are highly adaptable to the shape of the cylinders despite their reduced preload They have less friction and skim off the oil efficiently Assembly notes Make sure that the expander springs are correctly positioned during assembly This is particularly important when using pistons supplied with rings pre-fitted It is possible that the spring ends may have slipped over one another To simplify checking, both ends of the springs have colour markings The expander springs must not be overlapping as otherwise the oil control ring will not function properly The joints of the 3-piece oil control ring must be installed rotated through 120° Joint 3-piece oil control ring consisting of: Upper steel plate Spacer and expander spring Lower steel plate Colour marking Colour marking 645_045 Note As regards mounting the 3-piece oil control rings on the pistons, it is important to follow the procedure described in the workshop manual Scope of maintenance jobs Changing the oil According to service interval display, between 15,000 km / year and 30,000 km / years depending on driving style and conditions of use Air filter change interval 90,000 km Spark plug change interval 60,000 km / years Fuel filter change interval – Timing gear Chain (lifetime) Note The specifications in the current service literature generally apply 27 < Back Forward > Ξ Contents Appendix Glossary This glossary explains to you all terms which are shown in italics and indicated by an arrow ↗ in this self study programme ↗ Blow-by gases ↗ Performance class When the engine is running, blow-by gases flow from the combustion chamber and past the piston into the crankcase This is due to the high pressure inside the combustion chamber and the absolutely normal leakage that occurs around the piston rings Blow-by gases are extracted from the crankcase by the positive crankcase ventilation system and re-admitted into the combustion chamber In the Federal Republic of Germany mobile working machines are subdivided into performance classes according to the Federal Immission Control Act (regulations on emission limits for internal combustion engines) and the guidelines of the European Parliament Levels I, II, IIIA, IIIB and IV as well as performance classes 19 kW – 36 kW, 37 kW – 55 kW, 56 kW – 74 kW, 75 kW – 129 kW and 130 kW – 560 kW are differentiated by variable and nonvariable engine speed ↗ Cracked conrod This term derives from the method by which the conrod is manufactured The conrod shaft and conrod head cap are separated from another by controlled cracking The advantage of this process is that it provides an exact fit and a high degree of joining accuracy whereby only these two parts fit together perfectly Fracture surfaces 645_054 ↗ MPI MPI is the abbreviation for Multi Point Injection, an injection system for petrol engines where fuel is injected into the intake manifold upstream of the injectors In some engines it is used in combination with the FSI direct injection system Predetermined breaking point MPI injector Intake manifold ↗ FSI 645_053 FSI is the abbreviation for Fuel Stratified Injection, a technology used by Audi for direct fuel inejction into the combustion chamber in petrol engines Fuel is injected at pressures of up to 200 bar FSI injector Combustion chamber 645_055 28 < Back Forward > Ξ Contents Test your knowledge A new engine oil (0W-20) will be introduced at the market launch of the Audi A4 (type 8W) For which engines can it be used? □ a) High-performance engines only, i.e S models □ b) For all new engines and retroactively for all other engines □ c) For suitably rated new petrol and diesel engines Which aspects of the crankcase ventilation system in the new 2.0l TFSI engine have been modified compared with the previous engines (EA888 Gen.3)? □ □ □ a) The system has an overhead configuration The ventilation system is active at high engine load b) The crankcase is ventilated via a new extraction point located on one of the balancer shafts Otherwise, the ventilation pathway, blow-by gas treatment and ventilation are the same as in the previous engine generation c) The crankcase ventilation system of the new 2.0l TFSI engines for the Audi A4 (type 8W) is unchanged compared with the EA888 Gen.3 engines What is the task of the Audi valvelift system (AVS) on the 2.0l TFSI engine with engine code CVKB? □ □ a) The Audi valvelift system (AVS) is activated when the engine management system requests the B cycle combustion process in the partial-load range This reduces the lift and opening times of the intake valves b) If the Audi valvelift system (AVS) adjusts the cam elements on the intake camshaft at the request of the engine management system, the opening width of the exhaust valves is reduced This improves inflow into the exhaust turbocharger at low engine speeds and allows a faster build-up of charge pressure c) If the Audi valvelift system (AVS) is activated by the engine management system in the partial-load range, the valves in 2 cylinders are no longer opened Test solutions: c; b; a □ 29 < Back Forward > Ξ Contents Self study programmes For more information about the technology of the EA888 series engines, please refer to the following self study programmes SSP 384 The Audi 1.8l 4V TFSI Engine with Timing Chain SSP 411 The Audi 2.8l and 3.2l FSI engine with Audi valvelift system • Engine mechanicals • Demand-controlled fuel system • Audi valvelift system (AVS) SSP 436 Modifications to the chaindriven 4-cylinder TFSI engine SSP 606 Audi 1.8l and 2.0l series EA888 TFSI engines (3rd Generation) • Demand-controlled oil pump • Turbocharging • Engine mechanicals • High and low pressure fuel system SSP 626 Basics of Audi engine technology SSP 644 Audi A4 (type 8W) • Fuel system • Basic information about the engine mechanicals and subsystems Information on QR codes This SSP has been enhanced by electronic media (animations, videos and mini-WBTs) for more effective illustration of the content The references on the pages to the e-media are concealed within QR codes, which are two-dimensional pixel patterns You can scan those codes using a tablet or smartphone running the appropriate app, which will decipher the hidden web address To follow the link you require an Internet connection All e-media are managed on the Group Training Online (GTO) platform Before you can retrieve media, you need to set up a user account for GTO and log in after scanning the QR code On an iPhone, iPad and many Android devices, you can store your login credentials in the mobile browser This way, you can log in more easily the next time Make sure you protect your mobile device against unauthorised use by setting a PIN To read the QR codes, you need to obtain a QR scanner from the Apple® or Google® app store and install it on your mobile device For some media, other players may be required Please note that using the e-media over the mobile phone network can be very expensive, especially if using data roaming tariffs abroad This is your responsibility alone The best option is to use a Wi-Fi connection On PCs and notebooks, the e-media can be selected in the SSP PDF and then retrieved online after you log into GTO 30 Apple® is a registered trademark of Apple® Inc Google® is a registered trademark of Google® Inc < Back Forward > Ξ Contents Notes 31 All rights reserved Technical specifications are subject to change Copyright AUDI AG I/VK-35 service.training@audi.de AUDI AG D-85045 Ingolstadt Technical status 12/15 Printed in Germany A15.5S01.32.20 645 Audi Vorsprung durch Technik ... system of the new 2.0l TFSI engines for the Audi A4 (type 8W) is unchanged compared with the EA888 Gen.3 engines What is the task of the Audi valvelift system (AVS) on the 2.0l TFSI engine with... system (MPI ↗ and FSI ↗) Self Study Programme 606 "Audi 1.8l and 2.0l series EA888 TFSI engines (third generation)" • New TFSI combustion process • Audi valvelift system (AVS) on the intake side... Demand-controlled fuel system • Audi valvelift system (AVS) SSP 436 Modifications to the chaindriven 4-cylinder TFSI engine SSP 606 Audi 1.8l and 2.0l series EA888 TFSI engines (3rd Generation) •