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– Using adapter - T40058- , turn crankshaft in direction of engine
rotation -arrow- until cam of hydraulic compensation element
to be checked faces upwards.
– Push roller rocker finger down using a screwdriver -arrow- and
measure clearance between roller rocker finger and cam.
If it is possible to insert a feeler gauge of 0.20 mm between cam‐
shaft and roller rocker finger:
– Renew hydraulic compensation element
⇒ “3.4 Removing and installing camshafts”, page 140
Additional steps required
– Install radiator cowl
.
– Install cylinder head cover: left-side
.
3.8
Valve dimensions
Note
Inlet and exhaust valves must not be machined. Only grinding-in
is permitted.
Dimension
Inlet valve
Exhaust valve
∅ a
mm
33.85 ± 0.10
28.0 ± 0.1
∅ b
mm
5.980 ± 0.007
5.965 ± 0.007
c
mm
103.97 ± 0.20
101.87 ± 0.20
α
∠°
45
45
WARNING
♦ Care must be taken when disposing of old sodium-cooled
exhaust valves.
♦ The valves must be sawn in two with a metal saw between
the centre of the stem and valve head. When doing so, the
valves must not come into contact with water. After pre‐
paring the valves, throw a maximum of ten into a bucket
of water. Then step away immediately, since a chemical
reaction will occur in which the sodium filling burns.
♦ After performing these steps the valves can be disposed
of in the normal way.
3.9
Checking valve guides
Special tools and workshop equipment required
Audi A8 2003 ➤
10-cylinder direct petrol injection engine (5.2 ltr. 4-valve), mechanics - Edition 10.2013
154
Rep. gr.15 - Cylinder head, valve gear