engine AUDI A4 1997 B5 / 1.G AWM Engine Valve Gear Service Workshop Manual

15-37


Valve gear, servicing

Note:

Cylinder heads that have cracks between the
valve seats or between valve seat inserts and
the spark plug thread can be used further
without reducing service life, provided the
cracks do not exceed a maximum of 0.3 mm in
width, or when no more than the first 4 turns of
the spark plug threads are cracked.
Wait about 30 minutes after installing the
camshafts before starting the engine. Hydraulic
valve compensation elements have to settle
(otherwise valves will strike pistons).
After working on the valve gear, turn the engine
carefully at least 2 rotations to ensure that none
of the valves make contact when the starter is
operated.
Replace all gaskets and seals.
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15-51

Removing

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

- Remove engine cover -arrows-.
- Remove upper toothed belt guard Page 13
-35
.
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15-58

Removing

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

- Remove engine cover -arrows-.
- Remove upper toothed belt guard Page 13
-35
.

- Disconnect connector from camshaft position sensor -arrow-.
- Remove sensor housing.
- Remove sensor rotor and washer.
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15-63

Removing

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

- Remove engine cover -arrows-.
- Remove combination valve for secondary air inlet Page 26
-64
.

- Disconnect connector -arrow- from camshaft adjuster.
- Remove upper toothed belt guard Page 13
-35
.
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15-72


Note:
When turning the camshaft the crankshaft must not be at TDC. There is a
danger of damage to the valves/piston crown.
Note: - Align markings on camshaft sprocket with marking on cylinder head
cover.
- Align marking on vibration damper with marking on lower part of
toothed belt guard.
- Install toothed belt (adjust valve timing) Page 13
-44
.
Observe all instructions on removing and installing the toothed belt
Page 13
-40
.
Wait about 30 minutes after installing the camshafts before starting
the engine. Hydraulic valve compensation elements have to settle
(otherwise valves will strike pistons). After working on the valve gear, turn the engine carefully at least 2
rotations to ensure that none of the valves make contact when the
starter is operated.
Pa
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gear, servicin
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pair&id=AUDI.B5.GE06.15.2

15-74

Hydraulic valve lifters, checking


Special tools and equipment

Feeler gauge
Wood or plastic wedge

Note:
Hydraulic valve lifters cannot be adjusted or
repaired.
Irregular valve noise during starting is normal.

Test sequence

- Start engine and let run until coolant
temperature has reached approx. 80 C.

- Increase engine speed to about 2500 rpm for 2
minutes (perform road test if necessary).

Note:
If the irregular valve noises stop but recur
repeatedly during short journeys, a new oil
retention valve must be fitted. Oil retention valve
location: In oil filter bracket -Item 6 -, Page
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15-76

Note:

Wait about 30 minutes after installing the
camshafts before starting the engine. Hydraulic
valve compensation elements have to settle
(otherwise valves will strike pistons).
After working on the valve gear, turn the engine
carefully at least 2 rotations to ensure that none
of the valves make contact when the starter is
operated.
Pa
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gear, servicin
g
11/21/2002 htt
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yp
e=re
pair&id=AUDI.B5.GE06.15.2

15-85

- Install camshafts and camshaft adjuster Page
15
-67


Note:

Wait about 30 minutes after installing the
camshafts before starting the engine. Hydraulic
valve compensation elements have to settle
(otherwise valves will strike pistons).
After working on the valve gear, turn the engine
carefully at least 2 rotations to ensure that none
of the valves make contact when the starter is
operated.
Pa
ge 51 of 58 Valve
gear, servicin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
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yp
e=re
pair&id=AUDI.B5.GE06.15.2

15-88

Valve seats, reworking


Note:
If a good seating pattern cannot be obtained by
grinding the valve seats (lapping), they must be
refaced (reworked):

Special tools and equipment

Depth gauge
Valve seat machining tool

Note:
When repairing engines with leaking valves, it is
not sufficient to reface the valve seats and
replace the valves. The valve guides must also
be checked for wear. This is particularly
important on high mileage engines Page 15
-
86
.

Only rework the valve seats as far as is
necessary to ensure a good seating pattern.
Before starting to rework the valve seats,
calculate the maximum permissible reworking
dimension.
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