Intake System, Checking For Leaks Using VAG 1687 Diagnostic Tool
Intake System, Checking For Leaks Using VAG 1687 Diagnostic Tool
Diagnostic trouble codes (DTCs) related to fuel trim, charge pressure or mass air flow (MAF) may be caused by:
- Leaking (worn/torn) intake hoses during charge conditions
- Incorrectly torqued or improperly placed clamps on intake hoses etc. causing leaks during charge conditions
Check the charge air pressure system using the VAG 1687 Charge air system tester.
Special tool VAG 1687 Charge air system tester preliminary set-up
- Back off pressure regulator knob -2- of VAG 1687 fully to protect gauge when shop air supply is applied to assembly.
- Close valve -3- before gauge.
- Close valve -4- after gauge.
The shop air supply line will later be attached to the inlet of VAG 1687.
- Remove female fitting from tester (arrow) and install an appropriate "male" air fitting that will connect to your shop air supply line.
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.
- 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).
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.
- 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.
- Connect KLI9210 to VAG 1687/1 adapter (KLI9210 is shown attached to VAG 1687/1 at arrow on 1.8L Turbo).
Special tool LKI9210 (Evaporative system leak detector), preliminary set-up
- Connect smoke generator leads to vehicle battery.
- Turn valve to test (black arrow).
- Press smoke generator button to fill system with smoke (see instructions printed on tester).
With system filled with smoke:
- Remove smoke generator hose and connect VAG1687 quickly to prevent smoke from leaking out.
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.
- 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.
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.
- Open valve -3- between regulator valve and gauge.
- Adjust test pressure up to 0.5 bar by turning regulator valve -2-.
CAUTION:
- 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.
NOTE: Some pressure will be lost past the throttle plate.
- Readjust test pressure to 0.5 bar 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.
With VAS 5051 diagnostic tool connected:
- Erase DTC memory.
If smoke generator was not used to fill the system with smoke:
- Apply soapy water solution or equivalent to intake system connections.
NOTE: An ultrasonic detector may also be used to detect extremely small leaks.
- Inspect intake system connections for leaks.
- Repair any leaks found.
- Remove tester.
- Remove plug from crankcase ventilation hose.
- Remove air pressure adapter.
With VAS 5051 diagnostic tool connected:
- Erase DTC memory.