Engine - Intake System Leak Checking
Condition
24 07 06 Feb. 6, 2007 2010580 Supersedes T. B. Group 24 number 04-01 dated June 22, 2004 due to inclusion into ElsaWeb.
Intake System, Checking For Leaks Using the VAG Diagnostic Tool
Diagnostic trouble codes (DTC's) related to fuel trim, charge (boost) pressure or Mass air flow (MAF), may be caused by:
Leaking (worn/torn) intake hoses during charge conditions.
Incorrectly tightened or improperly placed, clamps on intake hoses etc., causing leaks during charge conditions.
Technical Background
Tools to assist technician when checking for charge air system leaks.
Production Solution
No production change required.
Service
The charge air pressure system can be checked using the VAG 1687 Charge air system tester along with the VAG1687/1 adapter as follows:
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 the assembly.
- Close valve -3- before gauge.
- Close valve -4- after gauge.
Shop air supply line will later be attached to 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 (See Note).
NOTE:
Use only approved air fittings to adapt shop air supply line to VAG 1687 tester.
Special tool VAG 1687/1 pressure adapter, installing
On Golf, Jetta and New Beetle Models:
- Separate intake hose from the Mass Airflow Sensor assembly (MAF).
- Insert VAG 1687/1 pressure adapter in intake hose -black arrow- using existing clamp (as shown).
- Remove crankcase ventilation valve or tube from intake hose at -white arrow-.
- Plug hose with appropriate metal plug and hose clamps supplied with VAG 1687/1 special tool kit at -white arrow-.
On Passat models:
- Separate intake hose from the Mass Airflow Sensor assembly (MAF).
- Insert VAG 1687/1 pressure adapter in intake hose -black arrow- using existing clamp (as shown).
- Remove crankcase ventilation valve or tube from intake hose at -white arrow-.
- Plug hose with appropriate metal plug and hose clamps supplied with VAG 1687/1 special tool kit at -white arrow-.
- Remove oil cap.
NOTE:
To help find small leaks, BEFORE pressurizing the system, fill system with smoke using special tool KLI9210 and adapter KLI9210/50 as outlined in this bulletin.
An Ultrasonic detector may also be used to detect extremely small leaks where smoke may not be visible.
Special tool KLI9210 (EVAP system leak detector)
- Install optional fitting KLI 9210/50 on hose of special tool KLI9210.
- Connect KLI9210 to VAG 1687/1 adapter (KLI 9210 is shown attached to VAG1687/1 at arrow on 1.8L Turbo).
Special tool KLI9210 (EVAP system leak detector), preliminary setup
- Setup KLI 9210 as described in user manual regarding self-test and output pressure.
- 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).
- Check for escaping smoke for two minutes.
Tip: Smoke may escape from crankcase hose or oil fill hole. This is normal.
With system filled with smoke:
- Remove smoke generator hose and connect VAG 1687 quickly to prevent smoke from leaking out.
- Connect VAG 1687 quickly to prevent smoke from leaking out.
Special tool VAG 1687 connecting to pressure adapter 1687/1
VAG 1687 is shown connected to VAG 1687/1 (black arrow)
Shop air supply 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 (see Note below) by turning the regulator valve -2-.
NOTE: DO NOT pressurize system above 0.5bar.
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.
Tip: Some pressure will be lost past the throttle plate.
- Readjust test pressure to 0.5 bar (see CAUTION above) by turning the regulator valve -2-.
- Listen for any very large intake leaks.
If smoke generator was used to fill the system with smoke:
- Check for smoke escaping from intake connections.
Tip: 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 5051/5052 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.
Tip: 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 5051/5052 diagnostic tool connected:
- Erase DTC memory.
If no leaks are found, but complaint still exists, refer to Repair Group 21 in ElsaWeb for detailed testing of charge system components.
Warranty
Non-VAS 5051/5052 diagnostic time under 1 hour, must be claimed per Service Circular VRT-00-03 dated Aug. 28, 2000.
Non-VAS 5051/5052 diagnostic time over 1 hour, must be claimed per Service Circular VWA-04-08 dated Mar, 17, 2004.
Required Parts and Tools
No Special Parts required. Always see ETKA for the latest part(s) information.