1999 AUDI A6 coolant

15-16


Rear sealing flange (left cylinder head)
The sealing flange and rear oil seal on the left cylinder head must be
replaced together as follows: - Press seal flush using 3241/1 press sleeve and 3241/3 bolt.
- Unbolt engine coolant expansion tank from bracket.
- Remove crankshaft ventilation line from cylinder head cover.
- Unbolt Camshaft Position (CMP) sensor.
Tightening torque: 10 Nm (7 ft lb)
- Unbolt shutter wheel for Camshaft Position (CMP) sensor G40 and
carefully pry out using screwdriver.
- Remove cylinder head cover.

- Remove double bearing cap (arrows).
- Remove seal and sealing flange.
- Clean running and sealing surfaces as well as contact surface of
double bearing cap.
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15-19

- Place VAG1306 drip tray beneath engine.

- Open engine coolant expansion tank cap.

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.

- With bumper removed, open coolant drain plug (arrow) on lower left of
radiator by turning it counterclockwise. If necessary, attach accessory
hose to connection.
- With bumper installed, pull off retaining clamp for lower right radiator
hose (from radiator to engine) and disconnect radiator hose from
radiator.

- Using 3247 hex ball socket, open coolant drain plug on engine (arrow)
as well.
- Unbolt engine coolant expansion tank from bracket and lay aside
(remove if necessary).
-
Disconnect crankshaft housing ventilation line from cylinder head
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15-20


- Disconnect blue harness connector on Intake Manifold Tuning (IMT)
valve.
- Disconnect black harness connector for intake air temperature sensor
on resonator.
- Cut tie wraps and move wiring to side.
- Disconnect vacuum line at cruise control vacuum diaphragm and at
vacuum booster.
- Unbolt cruise control vacuum diaphragm and unhook cruise control
vacuum diaphragm linkage at throttle body.
- Disconnect harness connector on throttle body and vacuum lines on
fuel pressure regulator.

- Disconnect harness connectors from camshaft adjustment valve and
from fuel injectors (arrows).
- Disconnect harness connectors from Engine Coolant Temperature
(ECT) sensor and Camshaft Position (CMP) sensor (arrows).
- Cut tie wraps on valve cover.
- Unclip wiring retainer on fuel rail and disconnect crankshaft housing
ventilation lines from left and right-side valve covers. Move hoses and
wiring clear (to rear).
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15-22


- Disconnect vacuum line at throttle body and line between vacuum
booster and intake air elbow (arrows).
- Remove intake air elbow.
- Remove intake manifold.
- Disconnect heated oxygen sensor harness connector at left-side of
heater core and set aside.

- Remove left-rear toothed belt guard (arrows).
- Unbolt coolant hose at rear of cylinder head.
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15-23


- Unbolt coolant hose at front of cylinder head (arrows).
- Using 3452 polydrive special tool, loosen cylinder head bolts in reverse
order of tightening sequence and remove.
- Carefully lift off cylinder head.

- When removing and installing, use 3452 polydrive together with
normal commercial 10 mm socket.
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15-24

Installing

Notes:

Bolt holes in engine block for cylinder head
bolts must be free of oil and coolant.
Always replace cylinder head bolts.
Vacuum line connections page 10-23
When installing a new cylinder head:

- Install centering pin for intake manifold.

- Replacement cylinder head may be used to
replace left or right cylinder head. Install sealing
cap at appropriate front end of replacement
cylinder head.

- Coat lip of sealing cap with sealant AMV 188
001 02.

- Using VW295 needle bearing drift press in sealing cap until lip of cap
seals with chamfer end of cylinder head.
- Before installing cylinder head, set crankshaft and camshafts to TDC
for cylinder 3.
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15-31

Camshafts and camshaft adjusters,
removing and installing


Removing

- Remove engine cover (arrows).
Cylinder head installed Lock carrier in service position page 13
-1
- Remove ribbed belt page 13
-8 .
- Remove toothed belt page 13
-12
.

Left-side cylinder head - Remove noise insulation panel (arrows).
- Unbolt engine coolant expansion tank from bracket and lay aside.
- Remove crankshaft housing ventilation line from valve cover.
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15-45

Hydraulic valve lifters, checking


CAUTION!

After installing new hydraulic valve lifters the
engine must not be started for about 30
minutes. The hydraulic valve lifters must
settle (otherwise valves will strike pistons).
Then turn crankshaft two full revolutions by
hand before starting.

Notes:

Only replace hydraulic valve lifters in complete
sets. Hydraulic valve lifters cannot be adjusted
or repaired.
Irregular valve noise when starting engine is
normal.

- Start engine and let run until coolant
temperature reaches at least 80 C.

- Increase RPM to 2500 for about 2 minutes. If
necessary, test drive vehicle.
If hydraulic valve lifters are still loud, locate faulty
valve lifter as follows:

- Remove cylinder head cover.
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