2000 AUDI A6 engine

19-14

- Replace coolant drain plug O-ring and install
coolant drain plug into engine.

Tightening torque: 20 Nm (15 ft lb).

- Install lower right coolant hose and secure with
retaining clip.

- Secure coolant drain valve to radiator.

- Screw VAG1274/9 onto expansion tank and insert VAG1274/10 into
adapter.

- Loosen clamp on coolant hose on heater core and pull back hose until
bleeder hole in coolant hose (arrow) is no longer sealed by connection.
- Top off coolant until it flows out from bleeder hole in coolant hose.
- Push coolant hose onto connection and tighten.
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19-15


- Loosen bleeder screw on lower coolant line (arrow) under expansion
tank (if necessary, unbolt expansion tank).
- Top off coolant until it flows out from bleeder screw.
- Close bleeder screw and tighten to 20 Nm (15 ft lb).

- Loosen bleeder screw on front coolant line (arrow) between power
steering pump and left-side of cylinder head.
- Top off coolant until it flows out from bleeder hole in coolant line.
- Close bleeder screw and tighten to 20 Nm (15 ft lb).
- Top up coolant to MAX mark.
- Install coolant expansion tank cap.
- Set heater controls to maximum heat position.
- Start engine and let run at idle for approx. 10 minutes.
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19-16

- Raise engine speed to approx. 2000 rpm for
approx. 5 minutes.

- Allow engine to idle until lower coolant hose on
radiator is hot.

- Check coolant level and top-off if necessary.
When engine is at normal operating
temperature, coolant level must be on MAX
mark. When engine is cold, coolant level must
be between MIN and MAX marks.

WARNING!

The cooling system is pressurized when the
engine is warm. When opening the expansion
tank, wear gloves and other appropriate
protection, cover the cap with a cloth and
open carefully to relieve system pressure
slowly.
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19-24

Installing
Installation is the reverse of removal, noting the
following:

Bleeder valve for thermostat (arrow) must be at the top.
- Install thermostat -4- into engine block.
- Moisten new O-ring -3- with coolant.

- Install connection -2- for thermostat and tighten bolt -1- to 10 Nm (7 ft
lb).
- Install and tension toothed belt page 13
-12
.
- Install ribbed belt page 13
-8 .
- Fill cooling system with coolant page 19
-11
.
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19-28

Cooling system, pressure test


Engine at operating temperature

WARNING!

The cooling system is pressurized when the
engine is warm. When opening the expansion
tank, wear gloves and other appropriate
protection, cover the cap with a cloth and
open carefully to relieve system pressure
slowly.

- Open cap on coolant expansion tank.

- Using VAG1274/8 adapter attach VAG1274 cooling system tester to
coolant expansion tank.
- Use tester hand pump to create a pressure of approx. 1.0 bar (14.5
psi).
- If pressure falls, check for leaks and repair.
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19-32

After-run coolant pump, checking


Note:

Control modules with an after-run time of 15
seconds after engine is turned off were installed
since start of production. As a running change
in m.y. 1999, control modules with an after-run
time of 3 minutes were installed.
The coolant after-run pump also continues to
run after the engine is started again before the
15 second or 3 minute cycle is completed.
The coolant after-run pump and the after-run
fan are controlled via the same control module.
After switching off the engine, the after-run pump
always runs for 15 seconds or 3 minutes after the
engine has been switched off. If during this time
the switch-on temperature of 102 C (coolant
temperature) is reached at the thermostat of the
second fan stage, the after-run pump continues
to run and the coolant fan continues to run in the
after-run stage until the switch-off temperature of
91 C of the coolant at thermostat has been
reached. The maximum running time of the after-
run pump is 10 minutes.
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11/21/2002 htt
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yp
e=re
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