Engine Cooling - 4.2l v8 5v, Bhf Audi S4 B7

Cooling system components, removing and installing

Note. The cooling system is pressurized when the engine is warm. Dissipate the pressure if necessary before starting repair work. Secure all hose connections with standard hose clamps. Special tool V.A.G 1921 is recommended for installing spring clips. Replace gaskets, oil seals and O-rings. The arrows on the coolant pipes and the ends of the coolant hoses must be aligned.

Connection diagram for coolant hoses

Note. The following list refers to items in (Scheme 1).

1. Right auxiliary radiator Removing and installing, see «RIGHT AUXILIARY RADIATOR, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) Use fresh coolant after replacement
2. Not installed
3. Thermostat For auxillary radiator
4. Oil cooler Removing and installing, see OIL COOLER, REMOVING AND INSTALLING
5. Cylinder head/cylinder block Use fresh coolant after replacement
6. Heating system heat exchanger Use fresh coolant after replacement
7. Bleed hole At coolant hose to heating system heat exchanger
8. Cap Checking pressure relief valve in cap. See «CHECKING PRESSURE RELIEF VALVE IN CAP»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf__checking-pressure-relief-valve-in-cap) .
9. Expansion tank
10. Not installed
11. Left auxiliary radiator Removing and installing, see «LEFT AUXILIARY RADIATOR, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) Use fresh coolant after replacement
12. Non-return valve
13. Radiator Removing and installing, see «RADIATOR, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) Use fresh coolant after replacement
14. Thermostat Removing and installing, see «THERMOSTAT, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf)
15. Coolant pump Removing and installing, see «COOLANT PUMP, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf)
16. Generator

Scheme 1

Scheme 2

1. Adapter V.A.G 1274/8
2. Tubular section V.A.G 1274/10
3. Drip tray V.A.G 1306
4. Hose clamp tool V.A.G 1921
5. Cooling system filler VAS 6096 with VAS 6096/1
6. Refractometer T10007

Draining

Note. Drained coolant must be collected in a clean container for disposal/re-use.

Scheme 3

Scheme 4

Scheme 5

1. Unscrew cap of coolant expansion tank.
2. On vehicles with auxiliary heater, remove bolts (arrows) for exhaust pipe of auxiliary/additional heater at sound insulation.
3. Unfasten quick-release fasteners -1-, remove bolts -2- and remove sound insulation.
4. Position drip tray V.A.G 1306 beneath engine.
5. Remove drain plug (arrow) at thermostat housing and drain coolant at engine.

Filling

1. The cooling system is filled all year round with a mixture of water and radiator anti-freezelanti-corrosion agent.
2. Exclusive use is to be made as coolant additive of G12+ as per TL VW 774 F. Other coolant additives could considerably impair anti-corrosion action in particular. The resultant damage could lead to loss of coolant and consequently to serious engine damage.
3. Coolant additive G12+ can be mixed with additive G12.
4. G12+ and coolant additives marked "meeting specification TL VW 774 F" prevent frost and corrosion damage, stop scale forming and at the same time also increase the boiling point. The cooling system must therefore be filled all year round with anti-freeze and anti-corrosion additive.
5. On account of the higher boiling point, the coolant helps to enhance engine reliability under heavy loads particularly in countries with tropical climates.
6. Frost protection must be guaranteed to around - 25 ° C (in countries with arctic climate to around -35 ° C).
7. The coolant concentration must not be reduced by adding water even in warmer seasons and in warmer countries. The anti-freeze ratio must be at least 40%.
8. If greater frost protection is required in very cold climates, the amount of G12+ can be increased, however only up to 60 % (giving frost protection to around -40 ° C) as otherwise frost protection decreases again and cooling efficiency is also impaired.
9. Exclusive use is to be made of clean drinking water for mixing coolant.
10. If radiator, heat exchanger, cylinder head, cylinder head gasket or cylinder block has been replaced, do not re-use old coolant.
11. Never re-use contaminated coolant.
12. Due to the coolant additive G12+ use only special tool T10007 to check the anti-freeze protection in the cooling system

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

1. Reinstall drain plug (arrow) with new sealing ring.
2. Fill coolant tank VAS 6096/1 with at least 12 liters of pre -mixed coolant in the correct mixture ratio. G12+ (40%) and water (60%) for anti -freeze protection down to -25 ° C G12+ (50%) and water (50%) for anti-freeze protection down to -35 ° C G12+ (60%) and water (40%) for anti-freeze protection down to -40 ° C
3. Screw adapter V.A.G 1274/8 onto coolant expansion tank.
4. Mount cooling system filler VAS 6096 on adapter V.A.G 1274/8.
5. Hold air discharge hose -1- over a small vessel -2-. A small quantity of coolant is entrained in the air discharged and is to be collected.
6. Close both valves -A- and -B- (lever at right angles to direction of flow).
7. Connect hose -3- to compressed air supply. Pressure: 6 to 10 bar
8. Open valve -B- (lever in direction of flow). Suction jet pump generates a vacuum in cooling system Pointer of indicator must move into green zone
9. Also briefly open valve -A- (lever in direction of flow) to fill hose of coolant tank VAS 6096/1 with coolant.
10. Close valve -A- again.
11. Leave valve -B- open for another 2 minutes. Suction jet pump continues to generate vacuum in cooling system Pointer of indicator must remain in green zone
12. Close valve -B-. Pointer of indicator must settle in green zone; vacuum in cooling system is then sufficient for subsequent filling Repeat procedure if pointer is below green zone Decrease in vacuum indicates leak in cooling system
13. Remove compressed air hose.
14. Open valve -A-. Vacuum in cooling system causes coolant to be drawn out of coolant tank VAS 6096/1; cooling system is filled.
15. Check coolant level and pour in coolant as far as MAX mark.
16. Screw adapter V.A.G 1274/8 to coolant expansion tank.
17. Attach special tool V.A.G 1274/10 to adapter.
18. Pull off rubber seal of plenum chamber cover.
19. Remove plenum chamber cover -1- toward front (arrows).
20. Fold back protective sleeve for coolant hoses at connection of heating system heat exchanger.
21. Disconnect coolant hose to heating system heat exchanger (heater core) and pull it back until vent hole in coolant hose (arrow) is no longer covered by connection.
22. Pour in coolant until there are no bubbles in coolant emerging from vent hole in coolant hose.
23. Attach coolant hose to connection and tighten.
24. Set passenger compartment temperature to "HI".
25. Start engine and let it warm up. Heating action must become apparent at latest when coolant temperature gauge needle starts to move
26. Switch off engine.
27. Check coolant level. Coolant level may be above MAX mark when engine is warm

Coolant pump and thermostat, overview

Note. The following list refers to items in (Scheme 14).

1. Housing For coolant pump Removing and installing, see «COOLANT PUMP, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf)
2. 10 Nm
3. Front coolant pipe Removing and installing, see «FRONT COOLANT PIPE, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf)
4. O-ring Replace
5. 10 Nm
6. Sealing ring Replace
7. Coolant pump Removing and installing, see «COOLANT PUMP, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf)
8. O-ring Replace
9. 10 Nm
10. Driveshaft For oil pump
11. O-ring Replace
12. Sealing ring Replace
13. Thermostat Removing and installing, see «THERMOSTAT, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) Installed position See «INSTALLED POSITION OF THERMOSTAT»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) . See «COOLANT PUMP, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf)
14. Housing For thermostat Removing and installing, see «THERMOSTAT, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf)
15. Drain plug, 25 Nm
16. Sealing ring Replace
17. 10 Nm

Scheme 14

Scheme 15

1. Bleed valve (arrow) facing up

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

1. Move lock carrier to service position. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION.
2. Remove front coolant pipe See «FRONT COOLANT PIPE, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf).
3. Disconnect coolant hose at bottom of radiator (arrow) and drain remaining coolant.
4. Disconnect coolant hoses at thermostat housing.
5. Remove bolts (arrows).
6. Remove thermostat housing.
7. Disconnect coolant hose -1-. (Scheme 18)
8. Remove bolts (arrows).
9. Take off coolant pump housing to front, paying attention to drive shaft for coolant pump. NOTE: Lock carrier has been removed in Fig.
10. Pull drive shaft (arrow) for coolant pump out of guide at oil pump.
11. Remove bolts (arrows).
12. Take coolant pump -2- out of housing -1-.

Installing

Note. Replace sealing rings and O-rings. Secure all hose connections with standard hose clamps.

Scheme 21

1. Insert drive shaft (arrow) for coolant pump in oil pump mount at engine.
2. Insert coolant pump in mounts at upper part of sump.

Note. To attach the drive flange to the drive shaft hex, reach with a finger into the lower pipe connection of the coolant pump and turn impeller until coolant pump can be fully installed.

Perform further installation in reverse order. Note the following

Scheme 22

1. Install thermostat. See «THERMOSTAT, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) .
2. Install front coolant pipe. See «FRONT COOLANT PIPE, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) .
3. Install lock carrier with attachments. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION .
4. Allow stop for torque reaction support to settle on rubber buffer for torque reaction support and tighten bolts (arrows) to 28 Nm.
5. Install front bumper. See FRONT BUMPER (except Cabriolet), or FRONT BUMPER (Cabriolet).
6. Fill with coolant. See «FILLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf__filling) .
7. Adjust headlights. See HEADLIGHTS, ADJUSTING (except Cabriolet), or HEADLIGHTS, ADJUSTING (Cabriolet, Halogen), or HEADLIGHTS, ADJUSTING (Cabriolet, gas discharge Xenon).

Tightening torques

TIGHTENING TORQUES: COOLANT PUMP

Special tools and equipment required

1. Seal installer 3265

Scheme 23

Scheme 24

Scheme 25

1. Drain coolant. See «COOLING SYSTEM, DRAINING AND FILLING WITH COOLANT»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) .
2. Disconnect coolant hoses at thermostat housing.
3. Remove bolts (arrows).
4. Remove thermostat housing.
5. Press down retainer with seal installer 3265 and turn retainer clockwise.

Install in reverse order. Note the following

Note. Replace sealing rings. Secure all hose connections with standard hose clamps.

Scheme 26

1. Clean and smooth sealing surface.
2. Pay close attention to installation position of thermostat: Installed position: Bleed valve (arrow) facing up.
3. Press down and turn retainer with seal installer 3265. Retainer must be engaged beneath tab of connection
4. Fill with coolant. See «FILLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf__filling) .

Tightening torque

TIGHTENING TORQUES: THERMOSTAT HOUSING

Coolant pipes/hoses, overview

Note. The following list refers to items in (Scheme 27).

1. Front coolant pipe Removing and installing, see «FRONT COOLANT PIPE, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf)
2. 10 Nm
3. Sealing ring Replace
4. Coolant hose To Generator
5. 10 Nm
6. Coolant hose To top of radiator
7. Right coolant pipe Removing and installing, see «RIGHT COOLANT PIPE, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf)
8. O-ring Replace
9. 10 Nm
10. Coolant hose To expansion tank
11. Rear coolant pipe Removing and installing, see «REAR COOLANT PIPE, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf)
12. O-ring Replace
13. Engine Coolant Temperature (ECT) sensor -G2-/-G62
14. Clip
15. Coolant hose To heating system heat exchanger
16. 10 Nm
17. Coolant hose To left auxiliary radiator
18. Left coolant pipe Removing and installing, see «LEFT COOLANT PIPE, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf)
19. Plug
20. Coolant hose To thermostat housing
21. O-ring Replace

Scheme 27

1. Drip tray V.A.G 1306

Scheme 28

Scheme 29

1. Drain coolant. See «COOLING SYSTEM, DRAINING AND FILLING WITH COOLANT»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) .
2. Move lock carrier to service position. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION .
3. Remove bolts (arrows) and remove torque reaction support from engine.
4. Position drip tray V.A.G 1306 beneath engine.
5. Remove bolts and remove coolant pipe at front of engine (arrows).

Scheme 30

Install in reverse order. Note the following

Note. Replace sealing rings and O-rings. Secure all hose connections with standard hose clamps.

Scheme 31

1. Install lock carrier with attachments. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION .
2. Allow stop for torque reaction support to settle on rubber buffer for torque reaction support and tighten bolts (arrows) to 28 Nm.
3. Install front bumper. See FRONT BUMPER (except Cabriolet), or FRONT BUMPER (Cabriolet).
4. Fill with coolant. See «FILLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf__filling) .
5. Adjust headlights. See HEADLIGHTS, ADJUSTING (except Cabriolet), or HEADLIGHTS, ADJUSTING (Cabriolet, Halogen), or HEADLIGHTS, ADJUSTING (Cabriolet, gas discharge Xenon).

TIGHTENING TORQUES: FRONT COOLANT PIPE

1. Spring-type clip pliers VAS 5024 A

Scheme 32

Removing

Note. All cable ties unfastened or cut open on removal are to be re-attached in same position on installation.

Scheme 33

Scheme 34

Scheme 35

Scheme 36

Scheme 37

Scheme 38

Scheme 39

Scheme 40

1. Drain coolant. See «COOLING SYSTEM, DRAINING AND FILLING WITH COOLANT»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf).
2. Move lock carrier to service position. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION.
3. Remove right coolant pipe. See «RIGHT COOLANT PIPE, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf).
4. Take support bar 10-222 A out of engine compartment. NOTE: Support bar is required for removal of right coolant pipe but would impede further work.
5. Remove coolant hoses -1- and -2-. (Scheme 33)
6. Remove fastener for coolant expansion tank (arrow).
7. Disconnect wire to Engine Coolant Level (ECL) warning switch -F66- at bottom of expansion tank.
8. Take connectors -1 to 4- out of holder on left of bulkhead.
9. Remove holder from bulkhead.
10. Disconnect vacuum pipe (arrow) to brake servo at bulkhead.
11. Disconnect coolant hose to heating system heat exchanger at coolant pipe on back of engine.
12. Disconnect coolant hose from Y -piece -arrow-.
13. Disconnect connector (arrow) for Camshaft Position (CMP) sensor 2 -G163- at left cylinder head. NOTE: The following illustrations show view from the rear with engine removed.
14. Disconnect connector (arrow) for Camshaft Position (CMP) sensor -G40- at right cylinder head.
15. Disconnect connector -2- at Engine Coolant Temperature (ECT) sensor -G2-/-G62-.
16. Remove nut -1- and take off wiring harness at rear coolant pipe.
17. Unfasten hose clamp -1- using VAS 5024 A. (Scheme 41)
18. Unfasten hose clamp -6- using VAS 5024 A and disconnect coolant hose.
19. Remove bolts -2 to 5-.
20. Disconnect rear coolant pipe.

Scheme 41

Install in reverse order. Note the following

Note. Replace O-rings. Re-attach all cable ties at same location on installation. Secure all hose connections with standard hose clamps.

Scheme 42

1. Clean and smooth sealing surfaces for O-rings before installing.
2. Coat new O-rings with acid-free grease (Vaseline), place rear coolant pipe in position and fasten.
3. Install right coolant pipe. See «RIGHT COOLANT PIPE, REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) .
4. Install lock carrier with attachments. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION .
5. Allow stop for torque reaction support to settle on rubber buffer for torque reaction support and tighten bolts (arrows) to 28 Nm.
6. Install front bumper. See FRONT BUMPER (except Cabriolet), or FRONT BUMPER (Cabriolet).
7. Fill with coolant. See «FILLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf__filling) .
8. Adjust headlights. See HEADLIGHTS, ADJUSTING (except Cabriolet), or HEADLIGHTS, ADJUSTING (Cabriolet, Halogen), or HEADLIGHTS, ADJUSTING (Cabriolet, gas discharge Xenon).

TIGHTENING TORQUES: REAR COOLANT PIPE

Special tools and workshop equipment required

1. Spring clip pliers V.A.G 1921

Scheme 43

Scheme 44

Scheme 45

Scheme 46

1. Remove engine. See ENGINE, REMOVING AND INSTALLING.
2. Place engine on workbench or a firm surface and secure in position with wooden blocks. WARNING: Engine must be placed in an absolutely firm position to avoid risk of accident. Do not set engine on sump.
3. Remove bolts -1- and -2-. (Scheme 44) NOTE: Leave hose (arrow) connected to power steering to stop oil escaping.
4. Remove bolt (arrow) and dipstick guide tube.
5. Remove bolts -1- and -2-. (Scheme 46)
6. Unfasten hose clamps (arrows) and disconnect left coolant pipe from coolant hoses.

Install in reverse order. Note the following

Note. Replace O-ring. Secure all hose connections with standard hose clamps.

1. Replace O-ring at dipstick guide tube and insert guide tube in hole in upper part of sump.
2. Install engine. See ENGINE, REMOVING AND INSTALLING .

TIGHTENING TORQUES: LEFT COOLANT PIPE

Scheme 47

Scheme 48

1. Support bar 10-222 A
2. Shackle 10-222 A12
3. VAS 5024 A Spring-type clip pliers
4. Special tool T40045 (6.5 mm plastic pads for edges of wing)

Scheme 49

Note. All cable ties unfastened or cut open on removal are to be re -attached in same position on installation.

Scheme 50

Scheme 51

Scheme 52

Scheme 53

Scheme 54

Scheme 55

Scheme 56

Scheme 57

Scheme 58

Scheme 59

Scheme 60

Scheme 61

Scheme 62

Scheme 63

Scheme 64

Scheme 65

1. Drain coolant. See «COOLING SYSTEM, DRAINING AND FILLING WITH COOLANT»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf).
2. Move lock carrier to service position. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION.
3. Remove holder for wiring harness at engine bracket on right (arrows).
4. Remove nut at bottom -1- of right engine mounting. NOTE: Please ignore item -2- in the illustration.
5. Remove rear engine cover (arrows).
6. Remove front engine cover (arrows -1- and -2-).
7. Remove cover -1- on right of engine compartment.
8. Disengage EVAP canister purge regulator valve -N80- -1- at air duct. (Scheme 55)
9. Remove bolts (arrows).
10. Remove air duct -2-.
11. Unscrew fuel hose from connection on fuel rail pipe. To do so, counterhold using an open-end wrench at each hex head and unscrew union nut. WARNING: The fuel system is pressurized. Wrap a cloth around the joint before opening the system. Then dissipate pressure by carefully unfastening the joint.
12. Disconnect connector -2- at EVAP canister purge regulator valve -N80-. (Scheme 56)
13. Disconnect connector -3-at mass air flow sensor.
14. Disconnect hose -1- to secondary air injection pump.
15. Disconnect air hose -4- at mass air flow sensor. (Scheme 56)
16. Move wiring harness clear at air cleaner housing.
17. Unfasten clip and take out air cleaner housing with mass air flow sensor.
18. Disconnect vacuum hose -1-.
19. Disconnect air hose -2- from throttle valve control module.
20. Disconnect vacuum hose (arrow) at intake manifold.
21. Disconnect crankcase breather hose from right cylinder head cover (arrow).
22. Take connectors -1 to 4- out of holder on right of bulkhead.
23. Move wires clear.
24. Attach shackle 10-222 A12 to rear right engine lifting eye. NOTE: Please ignore item -1- in the illustration.
25. Position support bar 10 -222 A on fender mounting flange.
26. Engage shackle 10 -222 A12 at spindle of support bar 10 -222 A.
27. Lift engine slightly with spindle of support bar.
28. Disconnect upper coolant hose (arrow) from radiator.
29. Disconnect air hose (arrow) to secondary air injection system combination valves.
30. Remove bolts -1- and -2-.
31. Unfasten hose clamps (arrows) and remove right coolant pipe from coolant hoses.
32. If necessary, disconnect support bar to take out coolant pipe.

Install in reverse order. Note the following

Note. Re-attach all cable ties at same location on installation. Secure all hose connections with standard hose clamps.

See

Scheme 66

1. Secure fuel hose to connection on fuel rail pipe. To do so, counterhold using an open -end wrench at each hex head -1- and -3- and tighten union nut -2- to 22 Nm.
2. Install lock carrier with attachments. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION .
3. Allow stop for torque reaction support to settle on rubber buffer for torque reaction support and tighten bolts (arrows) to 28 Nm.
4. Install front bumper. See FRONT BUMPER (except Cabriolet), or FRONT BUMPER (Cabriolet).
5. Fill with coolant. See «FILLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf__filling) .
6. Adjust headlights. See HEADLIGHTS, ADJUSTING (except Cabriolet), or HEADLIGHTS, ADJUSTING (Cabriolet, Halogen), or HEADLIGHTS, ADJUSTING (Cabriolet, gas discharge Xenon).

TIGHTENING TORQUES: RIGHT COOLANT PIPE

1. Drip tray V.A.G 1306
2. Oil collector

Scheme 67

Note. Drained coolant must be collected in a clean container for disposal/re -use.

Scheme 68

Scheme 69

Scheme 70

Scheme 71

Scheme 72

Scheme 73

Scheme 74

Scheme 75

Scheme 76

Scheme 77

Scheme 78

Scheme 79

Scheme 80

Scheme 81

1. Unscrew cap of coolant expansion tank.
2. On vehicles with auxiliary heater, remove bolts (arrows) for exhaust pipe of auxiliary/additional heater at sound insulation.
3. Unfasten quick-release fasteners -1-, remove bolts -2- and remove sound insulation.
4. Remove front bumper. See FRONT BUMPER (except Cabriolet), or FRONT BUMPER (Cabriolet).
5. Position drip tray V.A.G 1306 beneath engine.
6. Remove drain plug (arrow) at thermostat housing and drain coolant at engine.
7. Remove right air duct (arrow) in front of auxiliary radiator.
8. Remove left air duct (arrow) in front of auxiliary radiator.
9. Disconnect coolant hose at bottom of radiator (arrow) and drain remaining coolant.
10. Remove cover -1- on right of engine compartment.
11. Disengage EVAP canister purge regulator valve -N80- -1-at air duct. (Scheme 75)
12. Remove bolts (arrows).
13. Remove air duct -2-.
14. Disconnect upper coolant hose (arrow) from radiator.
15. Remove bolts (arrows) at air ducts on left and right of radiator.
16. Unclip temperature sensor -1- for ambient temperature gauge from holder and move wire clear.
17. Unfasten cooling coil for power steering hydraulic fluid (arrows); do not open hydraulic fluid circuit.
18. Tie up cooling coil for power steering hydraulic fluid to one side.
19. Remove bolt for Coolant fan control module -J293- from radiator (arrow). CAUTION: Do not open refrigerant circuit of air conditioner. NOTE: Avoid straining, kinking or bending refrigerant lines and hoses at the condenser and elsewhere to prevent damage to these components.
20. Disconnect connector -1- at High pressure sensor -G65-.
21. Remove bolts (arrows).
22. Remove condenser and swivel downward with lines connected.
23. Release both retaining pins for radiator and lift radiator (arrows).
24. Swivel top edge of radiator forward and lift off.

Install in reverse order. Note the following

1. Fill with coolant. See «FILLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf__filling) . NOTE: Entire coolant must be replaced following radiator replacement.
2. Install front bumper. See FRONT BUMPER (except Cabriolet), or FRONT BUMPER (Cabriolet).

TIGHTENING TORQUES: RADIATOR

1. Drip tray V.A.G 1306

Scheme 82

Scheme 83

1. Drain coolant. See «COOLING SYSTEM, DRAINING AND FILLING WITH COOLANT»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) .
2. Move lock carrier to service position. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION .
3. Disconnect coolant hoses -1- and -2-.
4. Remove bolt (arrow).
5. Remove left auxiliary radiator.

Install in reverse order. Note the following

Note. Secure all hose connections with standard hose clamps.

See

Scheme 84

1. Install lock carrier with attachments. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION .
2. Allow stop for torque reaction support to settle on rubber buffer for torque reaction support and tighten bolts (arrows) to 28 Nm.
3. Install front bumper. See FRONT BUMPER (except Cabriolet), or FRONT BUMPER (Cabriolet).
4. Fill with coolant. See «FILLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf__filling) . NOTE: The entire coolant quantity must be replaced following radiator replacement.
5. Adjust headlights. See HEADLIGHTS, ADJUSTING (except Cabriolet), or HEADLIGHTS, ADJUSTING (Cabriolet, Halogen), or HEADLIGHTS, ADJUSTING (Cabriolet, gas discharge Xenon).

TIGHTENING TORQUES: LEFT AUXILIARY RADIATOR

Scheme 85

1. Drip tray V.A.G 1306

Scheme 86

Scheme 87

Scheme 88

Scheme 89

1. Drain coolant. See «COOLING SYSTEM, DRAINING AND FILLING WITH COOLANT»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf).
2. Move lock carrier to service position. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION.
3. Unscrew fuel hose from connection on fuel rail pipe. To do so, counterhold using an open-end wrench at each hex head and unscrew union nut. WARNING: Fuel system is pressurized. Wrap a cloth around the joint before opening the system. Then dissipate the pressure by carefully unfastening the joint.
4. Disconnect connector -2- at EVAP canister purge regulator valve -N80-. (Scheme 86)
5. Disconnect connector -3- at mass air flow sensor.
6. Disconnect hose -1- to secondary air injection pump. (Scheme 86)
7. Disconnect air hose -4- at mass air flow sensor.
8. Move wiring harness clear at air cleaner housing.
9. Unfasten clip and take out air cleaner housing with mass air flow sensor.
10. Disconnect hose at top of auxiliary radiator (arrow).
11. Remove bolts -1- and -2-.
12. Remove bolt for wiring harness holder at engine bracket on right (arrow).
13. Disconnect coolant hose at bottom of auxiliary radiator (arrow).
14. Remove nuts -2- and take off holder -1-.
15. Remove right auxiliary radiator.

Install in reverse order. Note the following

Note. Secure all hose connections with standard hose clamps.

Scheme 90

1. Secure fuel hose to connection on fuel rail pipe. To do so, counterhold using an open -end wrench at each hex head and tighten union nut to 22 Nm.
2. Install lock carrier with attachments. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION .
3. Allow stop for torque reaction support to settle on rubber buffer for torque reaction support and tighten bolts (arrows) to 28 Nm.
4. Install front bumper. See FRONT BUMPER (except Cabriolet), or FRONT BUMPER (Cabriolet).
5. Fill with coolant. See «FILLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf__filling) . NOTE: The entire coolant quantity must be replaced following radiator replacement.
6. Adjust headlights. See HEADLIGHTS, ADJUSTING (except Cabriolet), or HEADLIGHTS, ADJUSTING (Cabriolet, Halogen), or HEADLIGHTS, ADJUSTING (Cabriolet, gas discharge Xenon).

TIGHTENING TORQUES SPECIFICATION

Scheme 91

1. Cooling system tester V.A.G 1274
2. Adapter V.A.G 1274/8
3. Adapter V.A.G 1274/9

Requirement

1. Engine warm

Work sequence

Scheme 92

1. Unscrew cap of coolant expansion tank.
2. Position tester V.A.G 1274 with adapter V.A.G 1274/8 on expansion tank.
3. Use hand pump of tester to generate a pressure of approx. 1.0 bar.
4. Locate leak and eliminate fault if there is a drop in pressure.

Checking pressure relief valve in cap

1. Position tester V.A.G 1274 with adapter V.A.G 1274/9 on cap.
2. Operate hand pump. Pressure relief valve must open at a pressure of 1.4 to 1.6 bar

Scheme 93

Function

The cooling system is provided with 2 electric coolant fans.

1. Coolant fan -V7- on left in direction of travel with Coolant fan control module -J293
2. Coolant fan -2-V177- on right in direction of travel with Coolant fan control module 2 -J671

Both fans are actuated with infinitely variable control by the engine control module via the corresponding coolant fan control module.

1. Contact 66 of the engine control module is the control output for coolant fan control 1.
2. Contact 104 of the engine control module is the control output for coolant fan control module 2.

The coolant fans are actuated on the basis of the following criteria

1. Fan request from air conditioner: Fan request is transmitted from air conditioner operating element via CAN bus to engine control module, from where it is relayed directly to fans
2. Normal engine operation: In normal operation and with engine idling, fans are controlled as a function of coolant and ambient temperatures.

Scheme 94

1. V.A.G 1526 A
2. V.A.G 1527 B
3. V.A.G 1594 A
4. V.A.G 1598/31
5. VAS 5051 with VAS 5051/1

Scheme 95

1. Connect vehicle diagnostic, testing and information system VAS 5051 and select vehicle system "01 - Engine electronic from list. Ignition must be on. Indicated on VAS 5051
2. From list -1- select diagnostic function "03 -Final control diagnosis".
3. Keep touching right arrow key until coolant fan control module 2 is activated. Coolant fan control module 2 -J671- switches Coolant fan -2- -V177- (right) on one time and slowly brings fan up to full speed.
4. Keep touching right arrow key until coolant fan control module 1 is activated. Coolant fan control module -J293- switches Coolant fan -V7- (left) on one time and slowly brings fan up to full speed.
5. Terminate function "03 - Final control diagnosis" by touching left arrow key.

If fan actuation does not react as described

1. Based on previously mentioned criteria, create preconditions for coolant fan start-up (e.g. switch on air conditioner, increase engine temperature accordingly).

Indicated on VAS 5051

Scheme 96

1. From list -1- select diagnostic function "08 - Reading measured value block".

Indicated on VAS 5051

Scheme 97

1 - Enter display group

1. Use keypad -2- to enter "135" for "Display group number 135" and confirm by touching Q key.

Indicated on VAS 5051

Scheme 98

1. Check display in zones -2- and -3-. Duty cycle of fan 1 (left): min. 10% Duty cycle of fan 2 (right): min. 10% NOTE: In the event of a fan request from the air conditioner and/or if the coolant temperature is greater than 98 °C, the duty cycle must increase to more than 10 % and the fans must start up.

If duty cycle does not increase to above 10 %

1. Read fault memory of engine control module.
2. Eliminate any faults displayed.

If relevant fan does not start up although duty cycle is above 10 %

1. Check Coolant fan -V7-. See «CHECKING COOLANT FAN -V7- (LEFT)»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) or «CHECKING COOLANT FAN -2- -V177- (RIGHT)»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) .

Requirements

1. Coolant fan fuses and coolant fan control module OK

Scheme 99

Scheme 100

Scheme 101

1. Remove cover -1- on left of engine compartment.
2. Take connector -1- out of holder and disconnect.
3. Connect multimeter for voltage measurement as follows. COOLANT FAN -V7- CIRCUIT TEST: TERMINALS 1 & $ Connector Contact Measure to 1 Engine Ground 4 Battery positive Specification: approx. battery voltage

If readings do not match specifications

1. Use wiring diagram to eliminate open circuit in wiring.

If readings match specifications

1. Connect multimeter for voltage measurement as follows. COOLANT FAN -V7- CIRCUIT TEST: TERMINAL 2 Connector Contact Measure to 2 Engine Ground Specification: approx. battery voltage

If reading does not match specification

1. Use wiring diagram to eliminate open circuit in wiring.

If reading matches specification

Scheme 102

1. Connect multimeter for voltage measurement between contacts 2 and 3 of connector. Vehicle diagnostic, testing and information system VAS 5051 connected; vehicle self-diagnosis and vehicle system "01 - Engine electronics" selected. Ignition must be on.

Indicated on VAS 5051

Scheme 103

1. From list -1- select diagnostic function "03 - Final control diagnosis".
2. Keep touching right arrow key until coolant fan control module 1 is activated. Voltage value must slowly drop from approx. battery voltage to roughly 8 V (and then increase again)
3. Terminate function "03 - Final control diagnosis" by touching left arrow key.

If reading does not match specification

Scheme 104

1. Connect test box V.A.G 1598/31 to wiring harness connectors. Actual engine control module is not to be connected. Connect Ground clip of test box to Ground (not (Scheme 104)). See WIRING AND COMPONENT CHECK USING TEST BOX V.A.G 1598/31. CAUTION: Observe the test conditions and select the required measuring range before connecting the test leads to prevent damaging the electronic components.
2. Check for open circuit and short to Ground/positive in following wiring. COOLANT FAN -V7- CIRCUIT TEST: TERMINAL 4 Connector Contact Test box V.A.G 1598/31 Socket 4 66
3. Use wiring diagram to eliminate open circuit in wiring/short circuit.

If no fault is found

Scheme 105

1. Remove front bumper. See FRONT BUMPER (except Cabriolet), or FRONT BUMPER (Cabriolet).
2. Connect multimeter with prods and plug-in adapters from V.A.G 1594 A between contacts 1 and 2 of brown connector at Coolant fan control module -J293-; leave connector attached. Vehicle diagnostic, testing and information system VAS 5051 connected; vehicle self-diagnosis and vehicle system "01 - Engine electronics" selected. Ignition must be on.

Indicated on VAS 5051

Scheme 106

1. From list -1- select diagnostic function "03 - Final control diagnosis".
2. Keep touching right arrow key until coolant fan control module 1 is activated. Voltage value must increase to approx. 10.5 V (and then decrease again)
3. Terminate function "03 - Final control diagnosis" by touching left arrow key.
4. Touch "06 - End of output".
5. Switch off ignition.

If reading matches specification, but fan does not run

1. Replace Coolant fan -V7-. See «COOLANT FAN -V7- (LEFT), REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) .

If reading does not match specification

1. Use wiring diagram to check wiring from connector at front left of engine compartment to Coolant fan control module -J293-.

Scheme 107

If no fault is found

1. Replace Coolant fan control module -J293-.

1. Coolant fan fuse OK

Scheme 108

1. Remove front bumper. See FRONT BUMPER (except Cabriolet), or FRONT BUMPER (Cabriolet).
2. Connect multimeter with prods and plug-in adapters from V.A.G 1594 A between contacts 1 and 2; leave connector for Coolant fan -2- -V177- attached. Vehicle diagnostic, testing and information system VAS 5051 connected; vehicle self-diagnosis and vehicle system "01 - Engine electronics" selected. Ignition must be on.

Indicated on VAS 5051

Scheme 109

1. From list -1- select diagnostic function "03 - Final control diagnosis".
2. Keep touching right arrow key until coolant fan control module 2 is activated. Voltage value must increase to approx. 9 V

If reading matches specification, but fan does not run

1. Replace Coolant fan -2-, -V177-. See «COOLANT FAN -2- -V177- (RIGHT), REMOVING AND INSTALLING»(/audi/s4/b7-2004-2008/remont/cooling-fan/#engine-cooling-42l-v8-5v-bhf) .

If reading does not match specification

Scheme 110

Scheme 111

1. Move lock carrier to service position. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION .
2. Unscrew Coolant fan control module 2 -J671- at front left longitudinal member (arrows).
3. Disconnect connector -2- at coolant fan control module 2.
4. Connect multimeter for voltage measurement as follows. COOLANT FAN -2-, -V177- CIRCUIT TEST: TERMINALS 1 & 2 Connector Contact Measure to 1 Battery positive 2 Engine Ground Specification: approx. battery voltage

If readings do not match specifications

1. Use wiring diagram to eliminate open circuit in wiring.

If readings match specifications

Scheme 112

Scheme 113

1. Disconnect connector -1- at Coolant fan control module 2 -J671-.
2. Connect multimeter for voltage measurement between contacts 1 and 2 of connector. Vehicle diagnostic, testing and information system VAS 5051 connected; vehicle self-diagnosis and vehicle system "01 - Engine electronics" selected. Ignition must be on.

Indicated on VAS 5051

Scheme 114

1. From list -1- select diagnostic function "03 - Final control diagnosis".
2. Keep touching right arrow key until coolant fan control module 2 is activated. Voltage value must slowly drop from approx. battery voltage to roughly 8 V (and then increase again).
3. Terminate function "03 - Final control diagnosis" by touching left arrow key.

If reading does not match specification

Scheme 115

Scheme 116

1. Connect test box V.A.G 1598/31 to wiring harness connectors. Actual engine control module is not to be connected. Connect Ground clip of test box to Ground (not (Scheme 116)). See WIRING AND COMPONENT CHECK USING TEST BOX V.A.G 1598/31. CAUTION: Observe the test conditions and select the required measuring range before connecting the test leads to prevent damaging the electronic components.
2. Check for open circuit and short to Ground/positive in following wiring. CONNECTOR CONTACT REFERENCE Connector Contact Test box V.A.G 1598/31 Socket 2 104
3. Use wiring diagram to eliminate open circuit in wiring/short circuit.

If no fault is found

1. Checking wiring from Coolant fan control module 2 -J671- to connector at longitudinal member (arrow).

Scheme 117

If no fault is found in wiring

1. Replace Coolant fan control module 2, -J671-.

Note. All cable ties unfastened or cut open on removal are to be re-attached in same position on installation.

Scheme 118

Scheme 119

1. Move lock carrier to service position. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION .
2. Disconnect connector (arrow) at Coolant fan control module -J293-.
3. Move wiring harness to coolant fan clear.
4. Remove bolts (arrows) and take out fan.

Install in reverse order. Note the following

Note. Re-attach all cable ties at same location on installation.

Scheme 120

1. Install lock carrier with attachments. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION .
2. Allow stop for torque reaction support to settle on rubber buffer for torque reaction support and tighten bolts (arrows) to 28 Nm.
3. Install front bumper. See FRONT BUMPER (except Cabriolet), or FRONT BUMPER (Cabriolet).
4. Adjust headlights. See HEADLIGHTS, ADJUSTING (except Cabriolet), or HEADLIGHTS, ADJUSTING (Cabriolet, Halogen), or HEADLIGHTS, ADJUSTING (Cabriolet, gas discharge Xenon).

TIGHTENING TORQUES: LEFT COOLANT FAN

Note. All cable ties unfastened or cut open on removal are to be re-attached in same position on installation.

Scheme 121

Scheme 122

1. Move lock carrier to service position. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION .
2. Disconnect connector (arrow).
3. Move wiring harness to coolant fan clear.
4. Remove bolt -1-.
5. Turn coolant fan in direction of arrow and remove.

Install in reverse order. Note the following

Note. Re-attach all cable ties at same location on installation.

Scheme 123

1. Install lock carrier with attachments. See LOCK CARRIER, MOVING TO SERVICE POSITION (except Cabriolet), or LOCK CARRIER, MOVING TO SERVICE POSITION .
2. Allow stop for torque reaction support to settle on rubber buffer for torque reaction support and tighten bolts (arrows) to 28 Nm.
3. Install front bumper. See FRONT BUMPER (except Cabriolet), or FRONT BUMPER (Cabriolet).
4. Adjust headlights. See HEADLIGHTS, ADJUSTING (except Cabriolet), or HEADLIGHTS, ADJUSTING (Cabriolet, Halogen), or HEADLIGHTS, ADJUSTING (Cabriolet, gas discharge Xenon).

TIGHTENING TORQUES: COOLANT FAN

See also:
• RIGHT AUXILIARY RADIATOR, REMOVING AND INSTALLING
• CHECKING PRESSURE RELIEF VALVE IN CAP
• FILLING