service AUDI A6 1995 C5 / 2.G AEB ATW Engines Valvetrain Servicing Workshop Manual

15-32


Valvetrain, servicing

Note:

Cylinder heads with small cracks between the
valve seats that are less than 0.3 mm (0.012
in.) wide and/or between one valve seat and
only the first 4 threads of the spark plug thread,
can continue to be used without reduced
service life.
Always replace gaskets, seals and O-rings.

CAUTION!
After installing the camshafts, the engine
must not be started for approx. 30 minutes.
The hydraulic valve lifters have to settle
(otherwise valves will strike the pistons).
After installing the valvetrain and lifters,
carefully rotate the crankshaft by hand at
least 2 full revolutions before starting to be
sure that valves do not strike the pistons.
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15-42

Oil seals for camshafts, replacing


Cylinder head installed
Lock carrier in service position Page 13
-1

Special tools and equipment

2085 seal puller
3241 seal installer
3036 retainer

Replacing exhaust camshaft oil seal

Removing

- Remove ribbed belt and ribbed belt tensioner
Page 13
-15
.

- Remove engine covers.

- Remove upper toothed belt cover Page 13
-
29
.

-
Turn crankshaft at central bolt of toothed belt gear in direction of
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15-50

Camshafts and hydraulic chain
tensioner, removing and installing


Cylinder head installed
Lock carrier in service position Page 13
-1

Special tools and equipment

3036 retainer
3366 bracket-tensioner

Removing

- Remove ribbed belt and ribbed belt tensioner
Page 13
-15
.

- Remove engine covers.

- Remove upper toothed belt cover Page 13
-
29
.

- Turn crankshaft at central bolt of toothed belt gear in direction of engine
rotation to TDC Cyl. 1 marking (arrows).
- Remove cylinder head cover Page 15
-17
.
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15-60

Hydraulic valve lifters, checking


Special tools and equipment

Feeler gauge
Wood or plastic wedge

Note:
Hydraulic valve lifters cannot be serviced.
Irregular valve noise when starting engine is
normal.

- Start engine and let run until coolant
temperature reaches at least 80 C (176 F).

- Increase RPM to 2500 for about 2 minutes; if
necessary test drive vehicle.

Note:
If irregular valve noises disappear but then
reappear during drive, replace oil retaining valve.
Oil retaining valve is located in oil filter bracket
Page 17
-6 .
If hydraulic valve lifters are still loud, locate faulty
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