check engine AUDI A4 1998 B5 / 1.G APB Engine Valve Gear Service User Guide

15-88

Hydraulic lifters, checking


Notes:

Replace malfunctioning lifters completely (lifters
cannot be adjusted or repaired).
When new lifters have been installed the engine
must not be started for about 30 minutes
(otherwise valves will strike pistons).
Irregular valve noises when starting engine are
normal.

- Start engine and run until coolant temperature
reaches approx. 80 C.

- Increase engine speed to about 2500 RPM for
approx. 2 minutes: if necessary, perform road
test.
If the hydraulic lifters are still noisy, locate
malfunctioning lifters as follows:

- Remove cylinder head cover.

- Rotate crankshaft clockwise by turning securing
bolt for toothed belt sprocket until cams of lifters
to be checked are pointing upward.
Pa
ge 89 of 99 Valve
gear, servicin
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11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.15.1

15-95

Valve guides, checking

When repairing engines or cylinder heads 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.

Wear limit
If the wear limit is exceeded, replace cylinder head. - Insert valve into valve guide so that end of valve stem is flush with end
of guide. The valve stems have different diameters, so only use an inlet
valve in an inlet guide and an exhaust valve in an exhaust guide.
- Measure amount of rock. Inlet valve guide
Exhaust valve guide
0.8 mm 0.8 mm
Pa
ge 96 of 99 Valve
gear, servicin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.15.1