1996 AUDI A4 AEB ATW Engines Charge Air System With Turbocharger Workshop Manual

21-71

WARNING!

Use only approved air fittings to adapt shop
air supply line to VAG 1687 tester.

Special tool VAG 1687/1 pressure adapter,
installing (1.8L Turbo)

- Separate intake hose from Mass Air Flow (MAF)
sensor assembly.

Special tool VAG 1687/1 pressure adapter, installing (2.7L BiTurbo)
Repair Manual, Maintenance; Air cleaner housing, cleaning; Air cleaner element, replacing
- Insert VAG 1687/1 pressure adapter in intake hose -black arrow- using
existing clamp (as shown).
- Remove crankcase ventilation tube from intake hose at -white arrow-.
- Remove upper air cleaner housing and hoses to intake manifold as
necessary

- Insert VAG 1687/1 pressure adapter in intake hose -white arrow- using
existing clamp (as shown).
- Disconnect engine crankcase ventilation hose from intake manifold -
black arrow-.
-
Plug intake manifold fitting (for crankcase ventilation hose) with
appropriate hose and metal plug using clamps supplied with VAG
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1687/1 special tool kit.
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21-72

Note:

To help find small leaks, BEFORE pressurizing
the system fill system with smoke using special
tool KLI9210 and adapter KLI9210/50 as
described on Page 21
-72
.

An ultrasonic detector may also be used to
detect extremely small leaks where smoke may
not be visible.

Special tool KLI9210 (Evaporative system
leak detector), connecting to 1.8L Turbo

- Install optional fitting LKI9210/50 on hose of
special tool KLI9210.

Special tool KLI9210 (Evaporative system leak detector), connecting
to 2.7L BiTurbo - Connect KLI9210 to VAG 1687/1 adapter (KLI9210 is shown attached
to VAG 1687/1 at arrow on 1.8L Turbo).
- Install optional fitting LKI9210/50 on hose of special tool KLI9210.

-
Connect KLI9210 to VAG 1687/1 adapter (KLI9210 is shown attached
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to VAG 1687/1 at arrow on 2.7L BiTurbo).
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21-73

Special tool LKI9210 (Evaporative system
leak detector), preliminary set-up

- Connect smoke generator leads to vehicle
battery.

With system filled with smoke:
Special tool VAG 1687, connecting to pressure adapter VAG 1687/1
(1.8L Turbo)
For illustrations purposes VAG is shown lying in the engine compartment.
In practice the tool should be hung from the hood. - Turn valve to test -black arrow-.
- Press smoke generator button to fill system with smoke (see
instructions printed on tester).
- Remove smoke generator hose and connect VAG1687 quickly to
prevent smoke from leaking out Page 21
-73
.
- Connect VAG 1687 quickly to prevent smoke from leaking out.

VAG 1687 is shown connected to VAG 1687/1 -black arrow-
Shop air supply will be connected to VAG 1687 -at white arrow-
- Perform pressure test Page 21
-75
.
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21-74

Special tool VAG 1687, connecting to
pressure adapter VAG 1687/1 (2.7L BiTurbo)
For illustrations purposes VAG is shown lying in
the engine compartment. In practice the tool
should be hung from the hood.

- Connect VAG 1687 quickly to prevent smoke
from leaking out.

VAG 1687 is shown connected to VAG 1687/1 -black arrow-
Shop air supply will be connected to VAG 1687 -at white arrow-
- Perform pressure test Page 21
-75
.
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21-75

Performing pressure test:

- With outlet hose -1- of VAG 1687 connected to air pressure adapter:
- Attach shop air supply line to previously installed male fitting Page
21
-70
.

CAUTION! - Open valve -3- between regulator valve and gauge.
- Adjust test pressure up to 0.5 bar ( CAUTION below) by turning
regulator valve -2-.
DO NOT pressurize the system above 0.5 bar!Doing so may force oil into the intake system which can damage
the engine.
- Slowly open outlet valve -4- (after gauge) to test hose connections.
- Observe pressure gauge for a drop in pressure.
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21-76

Note:
Some pressure will be lost past the throttle plate.

- Readjust test pressure to 0.5 bar ( CAUTION
above) by turning regulator valve -2-.
- Listen for any very large intake leaks.
If smoke generator was used to fill the system
with smoke:

- Inspect intake system connections for smoke at
leaks.

Note:
An ultrasonic detector may also be used to
detect extremely small leaks where smoke may
not be visible.

- Repair any leaks found.

- Remove tester.

- Remove plug from crankcase ventilation hose.

- Remove air pressure adapter.
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pair&id=AUDI.B5.GE02.21.3