3.0 V6 Tdi
3.0 V6 Tdi
3.0 V6 Tdi
The range of engines fitted in the Phaeton and Touareg is being extended by a hightech turbodiesel engine.
The 3.0l V6 TDI engine has been developed by Audi and is equipped with a piezo-controlled common rail fuel injection system.
The engine is combined with a diesel particulate filter and meets the EU 4 exhaust emission standard.
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Attention Note
The self-study programme portrays the design and function of new developments! The contents will not be updated.
For current testing, adjustment and repair instructions, please refer to the customer service literature intended for this purpose.
At a glance
In brief . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
In brief
The 3.0l V6 TDI engine
The 3.0l V6 TDI engine is a new diesel engine developed from the Audi V engine family. This engine family's special characteristic is its extremely short and compact design, which is achieved by means of a chain drive. The engine additionally combines high output and ample torque with smooth running characteristics and low exhaust emissions. A piezo-controlled common rail fuel injection system ensures high injection pressure and a flexible injection process. The engine is installed in the Volkswagen Phaeton and Touareg.
High-strength, compacted graphite iron cylinder block 4-valve technology Intake manifolds with swirl flaps Chain drive for valve control system, balancer shaft and oil pump
Common rail fuel injection system Piezo-controlled injectors (piezo injectors) Diesel particulate filter
Technical data
Engine code BMK (Phaeton) BKS (Touareg)
Design type Displacement Bore Stroke Compression ratio Valves per cylinder Firing sequence Max. output Max. torque Engine management system Fuel Exhaust gas cleaning Exhaust emission standard
6-cylinder V engine (90 V angle) 2967 cm3 83 mm 91.4 mm 17 : 1 4 1-4-3-6-2-5 165 kW at 4000 rpm 450 Nm at 1400 to 3250 rpm 500 Nm at 1750 to 2750 rpm
Bosch EDC 16 C common rail fuel injection system Diesel, at least 51 CN Oxidising catalytic converter, exhaust gas recirculation, diesel particulate filter EU 4
Torque and output graph In the Phaeton, the 3.0l V6 TDI engine achieves its maximum torque of 450 Nm as of an engine speed of 1600 rpm; this is available over a wide speed range, up to 3250 rpm. In the Touareg, the engine offers maximum torque of 500 Nm in the engine speed range from 1750 to 2750 rpm. Its maximum output of 165 kW is achieved at 4000 rpm in both vehicles.
Torque (Nm)
Output (kW)
Touareg
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UV photon honing
The cylinder contact surface is honed in the conventional manner and is then processed using UV photon honing. During this process, a laser beam melts the surface of the cylinder contact surface, and nitrogen penetrates it. This smoothes and hardens the cylinder surface.
Bearing frame
A grey cast iron bearing frame is bolted into the crankcase. This contains the support for the crankshaft and additionally stiffens the cylinder block.
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Pistons
The aluminium pistons are designed without valve pockets. The swirl is influenced by the ports in the cylinder head and the position of the swirl flaps in the intake module, and ensures optimum mixture formation. To cool the piston ring zone, the pistons are equipped with an annular cooling duct, into which oil is sprayed via piston spray nozzles.
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Exhaust camshaft
For the structure and function of the hydraulic valve clearance compensation elements, refer to self-study programme No. 183 "The 2.5l V6 TDI 4V engine".
Injector
The injectors are secured in the cylinder head with the aid of clamping pieces. They can be removed via small covers in the cylinder head cover.
4-valve technology
Exhaust camshaft
Injector
Two intake and two exhaust valves per cylinder are arranged vertically in the cylinder head.
Intake camshaft
The vertically positioned, centrally located injection valve is positioned directly over the central piston recess. This design leads to good mixture formation, resulting in low fuel consumption and low exhaust emissions.
Intake valves
Exhaust valves
Piston recess
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The shape, size and layout of the intake and exhaust ports ensure good volumetric efficiency and a favourable gas cycle in the combustion chamber. The intake ports are designed as spiral and tangential ports. Thanks to the tangential port, the inflowing air generates the desired, high degree of in-cylinder flow. Particularly at high speeds, the spiral port leads to good combustion chamber filling.
Spiral port
Tangential port
Exhaust port
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Intaken air
The swirl flaps are moved by the intake manifold flap motor via a push rod. To do this, the positioning motor is actuated by the engine control unit. An integrated sensor serves to feed back the current position of the swirl flaps.
The intake manifold flap motors must only be renewed completely together with the intake manifold lower section. Please observe the notes in the workshop manual!
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High engine speeds As of an engine speed of approx. 1250 rpm, the swirl flaps are open continuously. Good combustion chamber filling is achieved thanks to the increased air throughput. As of an engine speed of approx. 2750 rpm, the swirl flaps are opened completely.
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Spur gears
Intake camshaft
Intermediate disk
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Structure
The exhaust camshaft spur gear is split into two parts in the left-hand cylinder head. (The intake camshaft spur gear is split into two parts in the right-hand cylinder head.) The broader part of the spur gear (fixed spur gear) is positively connected to the camshaft. Three lugs are located on the front face. The narrower part of the spur gear (moveable spur gear) can be moved radially and axially. Recesses for the three lugs are located on its rear side.
Lugs
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How it works:
Both spur gear parts are pushed axially together via the force exerted by a diaphragm spring. Whilst this occurs, they are simultaneously caused to rotate via the lugs.
This rotational movement offsets the teeth of both spur gear parts and therefore leads to backlash compensation between the intake and exhaust camshafts' gear wheels.
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Crankshaft
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A central chain from the crankshaft to the intermediate gears (drive A), A chain from each of the intermediate gears to the intake camshafts (drives B and C), A chain from the crankshaft to the oil pump drive and to the balancershaft.
The camshaft chain sprockets have the same diameter as the crankshaft sprocket. The necessary camshaft: crankshaft ratio of 2 : 1 is achieved by means of the intermediate gears. The chains are tensioned by sprung, hydraulic chain tensioners; this system is maintenance-free.
Coolant pump
Alternator
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Pressure relief valve Oil pressure regulating valve Oil pan Oil pump
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Oil pump
The oil pump is a crescent pump. It operates according to the duocentric principle and is driven by chain drive D via a stub shaft. The length of the intake fitting has been adapted to the different oil pan designs.
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Oil cooler
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Functional principle
Turbocharger
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Diaphragms
Compression spring
If the vacuum in the intake port is high, the pressure control valve closes. In the case of a low vacuum in the intake port, it opens by means of the pressure spring's force.
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Hot Cold
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Cooler for engine coolant circuit Gearbox oil cooler Alternator Continued coolant circulation pump V51 (with towing attachment only) Air reservoir Heat exchanger Expansion tank
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Additional heater Choke Oil cooler Cooler for exhaust gas recirculation Exhaust gas recirculation flap Thermostat (opens as of a coolant temperature of 87 C)
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Continued coolant circulation pump V51 (vehicles with towing attachment only)
The continued coolant circulation pump V51 is an electrically driven pump. It is initialised according to a performance map by the engine control unit, and therefore ensures that the coolant is circulated for cooling purposes when the engine is "off".
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Coolant pump Coolant temperature sender G62 Radiator outlet coolant temperature sender G83 Water pump V36 Cooler for fuel cooling Fuel cooler Non-return valve Heating
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The injection pressure can be selected almost infinitely within the performance map. The availability of high injection pressure enables optimal mixture formation. A flexible pilot, primary and secondary injection process is achieved.
High-pressure accumulator (rail), cylinder bank 1 with injectors N30, N31, N32
Distributor between the rails High-pressure accumulator (rail), cylinder bank 2 Fuel pressure sender G247
A detailed description of the common rail fuel injection system can be found in selfstudy programme No. 351 "The common rail fuel injection system".
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Very short switching times Several injections per working cycle are possible Precisely apportionable injection quantities
The injection process, with a total of up to five partial injections per working cycle, has up to two pilot injections in the lower engine speed range and two secondary injections. This enables low emissions and smooth combustion.
Piezo effect
(Piezo [Greek] = pressure) The piezo-electric effect was discovered by Pierre Curie in 1880. If a crystalline lattice (turmaline, quartz) comprised of ions is deformed under pressure, electrical voltage is generated. The piezo-electric effect can also be reversed by applying an electric voltage. In this case, the crystal expands. This effect is used to control the injectors.
Piezo actuator
Connecting piston
Valve piston
Switching valve
Caution! The piezo-controlled injectors are actuated with a voltage of 110 148 V. Observe the safety instructions in the workshop manual!
Injector needle
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Supply and return pressure Return pressure between the injectors and pressure retention valve High pressure
In the fuel supply system, the fuel is delivered to the high-pressure pump from the fuel tank via the fuel filter by the pressurisation pump and the mechanical gear pump. The high fuel pressure required for injection is generated in the high-pressure pump and is fed into the high-pressure accumulator (rail).
High-pressure pump Mechanical gear pump Fuel metering valve N290 Pressure retention valve
High pressure 300 1600 bar Return pressure between injectors and pressure retention valve 10 bar Supply pressure Return pressure
Fuel filter
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From the high-pressure accumulator, the fuel is forwarded to the injectors, which inject it into the combustion chambers.
The pressure retention valve maintains the injectors' return pressure of 10 bar. This pressure is required for the piezo injectors' function.
Choke
In the Phaeton, the fuel is cooled by means of a fuel-air cooler on the vehicle floor.
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Adjustable turbocharger
Exhaust gas recirculation valve with exhaust gas recirculation cooler Oxidising catalytic converter
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Rear silencers
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Turbocharger
In the 3.0l V6 TDI engine, the charge pressure is generated by an adjustable turbocharger. This is equipped with adjustable guide vanes, which enable the flow of exhaust gas onto the turbine impeller to be influenced. The advantage of this is that optimal charge pressure and therefore good combustion are achieved throughout the entire engine speed range. In the lower engine speed range, the adjustable guide vanes offer high torque and good starting behaviour; in the upper engine speed range, they enable low fuel consumption and low emission values. The guide vanes are adjusted via an electric positioning motor. Electric initialisation makes fast turbocharger response behaviour and precise regulation possible. An exhaust gas temperature sender is located upstream of the turbocharger. The engine control unit uses the exhaust gas temperature sender's signal to protect the turbocharger from impermissibly high exhaust gas temperatures. In the event of excessive exhaust gas temperatures, e.g. during full-throttle operation, the engine output is reduced.
Guide vanes
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The principle of the adjustable turbocharger is explained in self-study programme No. 190 "Adjustable turbocharger".
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Coolant connections
Exhaust gas
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Cooler
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In the following cases, the bypass valve is also switched when the engine is at operating temperature: The bypass valve is opened during idling to maintain the oxidising catalytic converter's operating temperature. During deceleration, the bypass valve is switched back and forth once to guarantee unimpeded valve movement.
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3 12 5 4 7 9 10 11
6 8
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1 2 3 4 5 6
Control unit with display in dash panel insert J285 Diesel direct injection system control unit J248 Air mass meter G70 Diesel engine Exhaust gas temperature sender 1 G235 Turbocharger
Lambda probe G39 Oxidising catalytic converter Catalytic converter temperature sensor 1 G20 (Phaeton only) 10 Bank 1 exhaust gas temperature sender 2 G448 11 Particulate filter 12 Exhaust gas pressure sensor 1 G450 7 8 9
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Structure
The diesel particulate filter is comprised of a honeycombshaped ceramic body manufactured from silicon carbide, which is contained in a metal housing. The ceramic body is sub-divided into a multitude of small channels, which are sealed on alternating sides. This results in intake and exhaust channels which are separated by filter walls. The silicon carbide filter walls are porous and are coated with a substrate comprised of aluminium oxide and cerium oxide. The precious metal platinum, which serves as the catalyst, is vapour-deposited onto this substrate. The cerium oxide coating in the particulate filter lowers the carbon's ignition temperature and accelerates the thermal reaction with oxygen.
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Metal housing
Ceramic body
Function
The exhaust gas, which contains carbon, flows through the intake channels' filter walls. Unlike the gaseous components of the exhaust gas, the carbon particles are retained in the intake channels.
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Passive regeneration
During passive regeneration, the carbon particles are continuously combusted without engine management system intervention. This is primarily carried out at high engine loads, e.g. motorway driving, at exhaust gas temperatures of 350 500 C. In this case, the carbon particles are converted to carbon dioxide via a reaction with nitrogen dioxide.
Active regeneration
In urban traffic, i.e. low engine load, the exhaust gas temperatures are too low for passive regeneration. As no further carbon particles can be degraded, the carbon accumulates in the filter. As soon as a specific level of carbon has been reached in the filter, active regeneration is introduced by the engine management system. This process takes approximately 10 15 minutes. The carbon particles are combusted together with oxygen at an exhaust gas temperature of 600 650 C to form carbon dioxide.
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As soon as the carbon level limit value has been reached in the particulate filter, active regeneration is introduced by the engine management system. The following measures lead to a specific, temporary increase in exhaust gas temperature to approximately 600 650 C. In this temperature range, the carbon collected in the particulate filter oxidises to form carbon dioxide.
The intake air supply is regulated via the electric throttle valve.
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Exhaust gas recirculation is switched off to increase the combustion temperature and the oxygen content in the combustion chamber.
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Shortly after "retarded" main injection, the first secondary injection is introduced to increase the combustion temperature.
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Further secondary injection is introduced long after main injection. This fuel does not combust in the cylinder, but evaporates in the combustion chamber. The uncombusted hydrocarbons contained in this fuel vapour are oxidised in the oxidising catalytic converter. The heat which is generated during this process increases the exhaust gas temperature upstream of the particulate filter to approximately 620 C. The engine control unit uses the signals transmitted by the bank 1 exhaust gas temperature sender 2 (Touareg) or catalytic converter temperature sensor 1 (Phaeton) to calculate the injection quantity for retarded secondary injection.
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The charge pressure is adapted to prevent the driver from noticing a perceptible change in torque during the regeneration process.
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For detailed information on driving behaviour when the diesel particulate filter warning lamp lights up, please refer to the owner's manual.
A detailed description of the diesel particulate filter system can be found in self-study programme No. 336 "The catalytically coated diesel particulate filter".
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Coolant temperature sender G62 Radiator outlet coolant temperature sender G83
Lambda probe G39 Brake light switch F Brake pedal switch F47 Clutch pedal switch F36 Diesel direct injection system control unit J248
Bank 1 exhaust gas temperature sender 2 G448 Exhaust gas pressure sensor 1 G450 Intake air temperature sender G42 Charge air pressure sender G31
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Actuators
Intake manifold flap motor V157 Intake manifold flap 2 motor V275
Injectors for cylinders 1 6 N30, N31, N32, N33, N83 and N84
Exhaust gas recirculation cooler changeover valve N345 Radiator fan control unit J293 Radiator fan control unit 2 J671 Radiator fan V7 Radiator fan 2 V177
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Service
Special tools
Designation T40049 Adapter Tool Use For turning the crankshaft over.
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T40055 Socket
For loosening and tightening the union nut connection on high-pressure pipes in the common rail fuel injection system.
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T40058 Adapter
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T40061 Adapter
For correcting the position of the camshafts when adjusting the valve timing.
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Tool
Use For tensioning the chain sprocket when adjusting valve timing.
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T40095 Bracket
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T40096 Tensioner
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1.
What is the task of camshaft spur gear backlash compensation? a) b) c) Backlash compensation ensures that the camshafts are driven with little noise. Backlash compensation ensures that the intake camshaft is adjusted at high engine speeds. Backlash compensation ensures rigid engine speed compensation between the gears on the intake and exhaust camshaft.
2.
What do the swirl flaps in the intake manifold do? a) b) c) The swirl flaps interrupt the supply of air in the intake port. Due to this, less air is intaken and compressed, as a result of which engine coasting is gentle. Due to the position of the swirl flaps, air movement in the intake swirl port is adapted to the engine speed. In certain engine operating states, the swirl flaps generate a difference between the intake manifold pressure and exhaust gas pressure. This guarantees effective exhaust gas recirculation.
3.
In the timing chain drive, how is the necessary camshaft : crankshaft ratio of 2 : 1 achieved? a) b) c) Via hydraulic chain tensioners. Via intermediate gears. Via the length of the timing chains.
4.
Which statement regarding the diesel particulate filter system fitted in the 3.0l V6 TDI engine in the Phaeton and Touareg is correct? a) b) c) An oxidising catalytic converter and a catalytically coated diesel particulate filter are combined in one component and located beneath the bonnet. A catalytically coated diesel particulate filter is located in the exhaust system below the vehicle floor. The 3.0l V6 TDI engine has a diesel particulate filter system which is supported by an additive.
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Solutions: 1. a; 2. b; 3. b; 4. b
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VOLKSWAGEN AG, Wolfsburg All rights and technical changes reserved. 000.2811.64.20 Technical status 03.2005 Volkswagen AG Service Training VK-21 Brieffach 1995 D-38436 Wolfsburg
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