coolant temperature AUDI A4 1999 B5 / 1.G AHA ATQ Engines Valve Gear Service Manual

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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15-45

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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11/21/2002 htt
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yp
e=re
pair&id=AUDI.B5.GE03.15.1