Engine Cooling - 1.8l 4-cyl. 5v Turbo, Amb Audi A4 B6

Cooling system components, removing and installing

Note. Cooling system is under pressure when engine is warm. If necessary release pressure before repair work. Secure all hose connections with standard hose clamps: See Special tool VAG 1921 is recommended for installing spring clips. Always replace gaskets and sealing rings. Arrows on coolant lines and on ends of hoses must be aligned.

Coolant hose connection diagram

Note. The following list refers to items in (Scheme 31).

1. Heat exchanger for heater After replacing, fill with fresh coolant
2. Coolant line (bottom)
3. Expansion tank With cap Checking pressure relief valve in cap. See «CHECKING PRESSURE RELIEF VALVE IN CAP»(/audi/a4/b6-2000-2006/remont/cooling-fan/#engine-cooling-18l-4-cyl-5v-turbo-amb) .
4. Oil cooler Removing and installing, see «ENGINE-LUBRICATION»(ref-197056-S00966465262005101100000) .
5. Intake manifold
6. Coolant hose (bottom)
7. Coolant hose (top)
8. Radiator Removing and installing See «RADIATOR, REMOVING AND INSTALLING»(/audi/a4/b6-2000-2006/remont/cooling-fan/#engine-cooling-18l-4-cyl-5v-turbo-amb) After replacing, fill with fresh coolant
9. Coolant line (top
10. Coolant pump / thermostat Removing and installing coolant pump, see «COOLANT PUMP, REMOVING AND INSTALLING»(/audi/a4/b6-2000-2006/remont/cooling-fan/#engine-cooling-18l-4-cyl-5v-turbo-amb) Check for ease of movement
11. Turbocharger
12. Cylinder head / cylinder block After replacing, fill with fresh coolant
13. Connection

Scheme 31

Scheme 32

1. Refractometer T10007
2. Drip tray VAG 1306
3. Assembly tools for spring clips VAS 5024

Draining

Note. Catch drained-off coolant in a clean container for re-use or disposal.

Scheme 33

Scheme 34

Scheme 35

1. Open cap on coolant expansion tank.
2. Remove noise insulation -arrows-.
3. Place drip tray VAG 1306 under engine.
4. Pull retaining clip -1-for coolant temperature sender -G2- -2- off bottom coolant hose and drain off coolant from radiator.
5. Also disconnect coolant hose from oil cooler -arrow- and drain off remaining coolant.

Note. Observe disposal regulations.

Filling

Note. Only use coolant additive G 12 - meeting specification TL VW 774 D. Identifiable by: red color

1. Never mix G 12 with other coolant additives .
2. If fluid in expansion tank is brown, G 012 A8 D has been mixed with a different type of coolant. In this case, flush out cooling system and replace coolant. To flush out, fill cooling system with clean water and allow engine to run for approx. 2 minutes. This should remove virtually all the old coolant .
3. G 011 A8 C or G 012 A8 D and coolant additives marked "meeting TL VW 774 C" or "meeting TL VW 774 D" prevent frost and corrosion damage and stop scale forming. They also raise the boiling point. The cooling system must therefore be filled all year round with the correct anti-freeze and anti-corrosion additive .
4. On account of the higher boiling point, the coolant helps to enhance engine reliability under heavy loads particularly in countries with tropical climates .
5. Frost protection must be guaranteed to around - 25 ° C (in countries with arctic climate to around -35 ° C) .
6. 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% .
7. If greater frost protection is required in very cold climates, the amount of G 012 A8 D 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 .
8. Only use clean drinking water for mixing coolant .
9. If radiator, heat exchanger, cylinder head or cylinder head gasket is replaced, do not reuse old coolant .

Recommended mixture ratios

COOLANT MIXTURE RATIOS

Scheme 36

Scheme 37

1. Insert coolant temperature sender -G2 -2- back into bottom coolant hose and attach clip -1-.
2. Attach coolant hose to oil cooler.
3. Screw adapter VAG 1274/8 onto coolant expansion tank.
4. Fit special tool VAG 1274/10 onto adapter.
5. Fill cooling system with coolant.
6. Seal expansion tank.
7. Start engine and maintain engine speed of approx. 2000 RPM for approx. 3 minutes.
8. Then allow engine to run at idling speed until lower hose on radiator becomes hot.

1. Check coolant level and top up if necessary. When engine is at normal operating temperature, coolant level must be at max. mark; when engine is cold, coolant level must be between min. and max. marks.
2. Switch off engine.

Scheme 38

1. Refractometer T10007
2. Drip tray VAG 1306
3. Torque wrench (5...50 Nm) VAG 1331
4. Assembly tools for spring clips VAS 5024

Scheme 39

Scheme 40

1. Remove front bumper: See «FRONT BUMPER»(/audi/a4/b6-2000-2006/remont/exterior-body-panels/#bumpers-except-cabriolet) (except Cabriolet), or «FRONT BUMPER»(/audi/a4/b6-2000-2006/remont/exterior-body-panels/#bumpers-cabriolet) (Cabriolet).
2. Drain off coolant. See «COOLING SYSTEM, DRAINING AND FILLING»(/audi/a4/b6-2000-2006/remont/cooling-fan/#engine-cooling-18l-4-cyl-5v-turbo-amb) .
3. Remove coolant hose couplers from top and bottom of radiator.
4. Remove air ducts on left and right of radiator -arrows-.
5. Disconnect connector -1-from air conditioner pressure switch -F129-.
6. Disconnect connector -2-from ambient temperature sensor.
7. Move both wires clear.

1. Unbolt condenser -arrows-from radiator.

Note. To prevent damage to condenser and refrigerant lines/hoses ensure that lines and hoses are not stretched, kinked or bent.

Scheme 41

Scheme 42

1. Carefully swivel condenser downward and set down.
2. Release two retaining bolts for radiator and pull out upward -arrows-.
3. Swivel radiator forward out of lock carrier and lift out.

Installing

Install in reverse order, paying attention to the following

1. Fill coolant system. See «COOLING SYSTEM, DRAINING AND FILLING»(/audi/a4/b6-2000-2006/remont/cooling-fan/#engine-cooling-18l-4-cyl-5v-turbo-amb) .
2. Install front bumper: See «FRONT BUMPER»(/audi/a4/b6-2000-2006/remont/exterior-body-panels/#bumpers-except-cabriolet) (except Cabriolet), or «FRONT BUMPER»(/audi/a4/b6-2000-2006/remont/exterior-body-panels/#bumpers-cabriolet) (Cabriolet).

Scheme 43

1. Refractometer T10007
2. Drip tray VAG 1306
3. Torque wrench (5 to 50 Nm) VAG 1331
4. Assembly tools for spring clips VAS 5024

Removing

Note. Always replace gaskets and sealing rings.

Scheme 44

Scheme 45

1. Front bumper, removing and installing: See «FRONT BUMPER»(/audi/a4/b6-2000-2006/remont/exterior-body-panels/#bumpers-except-cabriolet) (except Cabriolet), or «FRONT BUMPER»(/audi/a4/b6-2000-2006/remont/exterior-body-panels/#bumpers-cabriolet) (Cabriolet). Move lock carrier to service position. See «LOCK CARRIER, MOVING TO SERVICE POSITION»(/audi/a4/b6-2000-2006/remont/exterior-body-panels/#body-front-except-cabriolet__lock-carrier-moving-to-service-position) (except Cabriolet), or «LOCK CARRIER, MOVING TO SERVICE POSITION»(/audi/a4/b6-2000-2006/remont/exterior-body-panels/#body-front-cabriolet__lock-carrier-moving-to-service-position) (Cabriolet).
2. Drain off coolant. See «COOLING SYSTEM, DRAINING AND FILLING»(/audi/a4/b6-2000-2006/remont/cooling-fan/#engine-cooling-18l-4-cyl-5v-turbo-amb) . Remove radiator. See «RADIATOR, REMOVING AND INSTALLING»(/audi/a4/b6-2000-2006/remont/cooling-fan/#engine-cooling-18l-4-cyl-5v-turbo-amb) .
3. Disconnect connectors -1- and -2- and move fan motor wires clear.
4. Unbolt radiator fan -arrows- from radiator cowl.

Install in reverse order, paying attention to the following

1. Install front bumper: See «FRONT BUMPER»(/audi/a4/b6-2000-2006/remont/exterior-body-panels/#bumpers-except-cabriolet) (except Cabriolet), or «FRONT BUMPER»(/audi/a4/b6-2000-2006/remont/exterior-body-panels/#bumpers-cabriolet) (Cabriolet).

Scheme 46

1. Refractometer T10007
2. Drip tray VAG 1306
3. Torque wrench (5 to 50 Nm) VAG 1331
4. Assembly tools for spring clips VAS 5024

Note. Always replace gaskets and sealing rings. Remove toothed belt completely so that it cannot be damaged by coolant.

Scheme 47

1. Drain cooling system. See «COOLING SYSTEM, DRAINING AND FILLING»(/audi/a4/b6-2000-2006/remont/cooling-fan/#engine-cooling-18l-4-cyl-5v-turbo-amb) .
2. Remove ribbed belt. See «RIBBED BELT, REMOVING AND INSTALLING»(ref-197056-S06598932702005101100000) .
3. Remove ribbed belt tensioning element.
4. Remove toothed belt. See «TOOTHED DRIVE BELT, REMOVING, INSTALLING AND TENSIONING»(ref-197056-S06449327332005101100000) .
5. Remove bolts -arrows- securing coolant pump and remove coolant pump.

Install in reverse order, paying attention to the following

Scheme 48

1. Moisten new O-ring -3-with coolant.
2. Insert coolant pump into cylinder block and tighten securing bolts -1-. Tightening torque: 15 Nm

How to install toothed belt and adjust valve timing. See TOOTHED DRIVE BELT, REMOVING, INSTALLING AND TENSIONING .

1. Install ribbed belt tensioning element. Tightening torque: 25 Nm
2. Install ribbed belt. See «RIBBED BELT, REMOVING AND INSTALLING»(ref-197056-S06598932702005101100000) .
3. Fill coolant system. See «COOLING SYSTEM, DRAINING AND FILLING»(/audi/a4/b6-2000-2006/remont/cooling-fan/#engine-cooling-18l-4-cyl-5v-turbo-amb) .

Scheme 49

1. VAG 1274
2. Adapter VAG 1274/8
3. Adapter VAG 1274/9

Test requirement

1. Engine warm.

Scheme 50

1. Open cap on coolant expansion tank.
2. Install tester VAG 1274 with adapter VAG 1274/8 onto expansion tank.
3. Use tester hand pump to generate pressure of approx. 1.0 bar.
4. If there is a drop in pressure, locate leak and eliminate fault.

Scheme 51

1. Install tester VAG 1274 with adapter VAG 1274/9 onto cap.
2. Operate hand pump. Pressure relief valve must open at pressure of 1.4 to 1.6 bar.

See also:
• FRONT BUMPER
• FRONT BUMPER
• LOCK CARRIER, MOVING TO SERVICE POSITION
• LOCK CARRIER, MOVING TO SERVICE POSITION
• CHECKING PRESSURE RELIEF VALVE IN CAP