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Removal/installation & Specifications (2.8l v6) Audi A6 C4

Cooling System (mechanical) 3 illustrations ~770 words

COOLING SYSTEM, COMPONENTS

Note. Always replace seals and gaskets. Check thermal switch for proper function. See COOLANT FAN CONTROL (FC) THERMAL SWITCH, CHECKING . It is not necessary to remove the toothed belt to remove the thermostat. Arrows on ends of hoses must be aligned with arrows on coolant pipes. Tightening torque for coolant pipe hose clamps: 3-3.5 Nm (27-31 in lb). An oil cooler, located between the oil filter and the oil filter bracket, is connected to the coolant circuit.

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

  1. Thermostat Replacing. See «THERMOSTAT, REPLACING»(/audi/a6/c4-1994-1997/remont/cooling-system-mechanical/#removalinstallation-specifications-28l-v6__thermostat-replacing) . Start of opening. See «THERMOSTAT, REPLACING»(/audi/a6/c4-1994-1997/remont/cooling-system-mechanical/#removalinstallation-specifications-28l-v6__thermostat-replacing) .
  2. Seal Always replace
  3. Thermostat housing
  4. 10 Nm (7 ft lb)
  5. Gasket Always replace
  6. Coolant Pump To remove and install, remove ribbed drive belt and toothed belt
  7. 10 Nm (7 ft lb)

Scheme 1

Scheme 1
Scheme 1

COOLANT PIPES, LAYOUT

Note. The intake manifold must be removed first in order to remove the coolant pipes. Arrows on ends of hoses must be aligned with arrows on coolant pipes. Tightening torque for coolant pipe hose clamps: 3-3.5 Nm (27-31 in lb). Always replace gaskets and seals.

Note. The following list refers to items in (Scheme 2).

  1. Large coolant pipe
  2. Bleed screw Tightening torque: 15 Nm (11 ft lb) Filling system. See «COOLING SYSTEM, DRAINING AND FILLING»(/audi/a6/c4-1994-1997/remont/cooling-system-mechanical/#removalinstallation-specifications-28l-v6__cooling-system-draining-and-filling) .
  3. Engine Coolant Temperature (ECT) G62- Tightening torque: 15 Nm (11 ft lb)
  4. 10 Nm (7 ft lb)
  5. Small coolant pipe
  6. 20 Nm (15 ft lb)
  7. Electronic Engine Coolant Temperature (ECT) thermal switch F76
  8. 10 Nm (7 ft lb)

Scheme 2

Scheme 2
Scheme 2

THERMOSTAT, REPLACING

  1. Remove timing belt. See «TIMING BELT»(ref-155373-S22559391872003061300000) .
  2. Drain coolant into suitable container if it is to be reused.
  3. Remove thermostat housing from under toothed belt cover.
  4. Lift out housing.

Installation position of thermostat. The vent valve must be installed facing up (arrow).

Scheme 3

Scheme 3
Scheme 3
  1. Opens approx. 87° C(189° F)
  2. Closes approx. 102° C (216° F)
  3. Stroke: minimum 8.0 mm (5/16 in.)

COOLANT FAN CONTROL (FC) THERMAL SWITCH, CHECKING

The coolant fan control thermal switch -F54- is located in the radiator at the bottom left.

Switch 3-PoleSwitching temperature
OnOff
1 = Stage 192-97° C (198-207° F)Approx. 84° C (183° F)
2 = Stage 299-105° C (210-221° F)Approx. 91° C (196° F)
3 = Positive (B+)

COOLANT FAN CONTROL (FC) THERMAL SWITCH, CHECKING

COOLING SYSTEM LEAKS, CHECKING

CAUTIONIf coolant is hot, carefully remove expansion tank cap.
  1. Engine must be at operating temperature.
  1. Connect cooling system tester VW 1274 to expansion tank using adapter VW 1274/1.
  2. Operate the hand pump to create a pressure of approx. 1 bar (15 psi).

If the pressure drops quickly

  1. Locate and repair leak in the cooling system.

EXPANSION TANK CAP, PRESSURE TESTING

  1. Screw cap onto cooling system tester VW 1274 with adapter VW 1274/1.
  2. Operate hand pump.
  3. Pressure relief valve must open at 1.2-1.5 bar (17-22 psi).

COOLING SYSTEM, DRAINING AND FILLING

Note. Prominent designations for coolant additives are G 011 A8B or C. There are coolant additives that correspond to the TLVW, but are not released by VW/Audi. Only coolant additives with the designation J 011 A8B or C can be used. The cooling system is filled year round with a mixture of water and J 011 A8B anti-freeze. J 011 A8B prevents freezing, corrosion damage and scale formation and raises the coolant boiling point. For these reasons the cooling system should be filled with J 011 A8B anti-freeze and anti-corrosion additive all the year round. Due to its high boiling point, coolant is an aid to operational efficiency when the engine is operating at full load, particularly in tropical climates. Coolant must be drained and replaced if either the engine or one of the cylinder heads has been replaced, or if the coolant has become contaminated.

Draining

  1. Using special tool 3247, drain coolant from engine drain plug (arrow) and at drain plug on bottom left of radiator. Tightening torque: 20 Nm (15 ft lb)
  2. Remove cap from expansion tank.

Filling

Recommended mixing rations for 8 liter (8.4 qt.) capacity, see COOLANT FILLING RECOMMENDATIONS .

Frost ProtectionJ 011 A8B or CWater
25° C (-13° F)3.2L (3.4 qt.)4.8L (5.1 qt.)
35° C (-31° F) (1)4.0L (4.2 qt)4.0L (4.2 qt)
(1) For cold climates
(1)For cold climates

COOLANT FILLING RECOMMENDATIONS

  1. back off each of two bleed screw approx. 2 turns. In coolant hose to heater core, right, next to brake booster Bleed screw in large coolant pipe, next to engine coolant temperature sensor. See «COOLANT PIPES, LAYOUT»(/audi/a6/c4-1994-1997/remont/cooling-system-mechanical/#removalinstallation-specifications-28l-v6__coolant-pipes-layout) .
  2. Pour coolant into expansion tank.
  3. Check bleed screws and close when coolant starts to run out.
  4. Fill expansion tank until level reaches top edge.
  5. Install cap on expansion tank.
  6. Run engine at idle until coolant fan has switched on once.
  7. Increase engine speed to 2000 RPM for approx. 30 seconds.
  8. Stop engine (switch ignition off).
  9. Check coolant level in expansion tank and top up to MAX mark if necessary.

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