Intake Air System, Checking For Leaks (Outside Air)

INTAKE AIR SYSTEM, CHECKING FOR LEAKS (OUTSIDE AIR)

Special tools, testers and auxiliary items
- VAG 1551 Scan Tool (ST) or vehicle system tester VAG 1552 with VAG 1551/3 adapter cable
- Engine leak detector spray G 001 800 A1

WARNING! The safety precautions listed on the leak detector spray container must be followed

NOTE:
- The vacuum in the intake system will cause the leak detector spray to be drawn in with outside air.
- The leak detector spray reduces the flammability of the mixture. This leads to a drop in engine speed (idle RPM) and to a significant increase in CO content.

Test sequence
- Start engine and run at idle speed.
- Connect VAG 1551 scan tool (VAG 1552) and insert "Engine Electronics" address word 01. Carry out selection at idle. RTefer to "On-Board Diagnostic". Testing and Inspection

Indicated on display

Rapid data transfer HELP
Select function XX

- Press buttons -0- and -8- to select "Read Measuring Value Block" function 08.
- Press -Q- button to confirm input.

Indicated on display

Read measuring value block HELP
Input display group number XXX

- Press -0-, -0- and -1- to input display group number 001.
- Press -Q- button to confirm input.

Indicated on display (1, 2, 3 and 4 = Display fields)

Read measuring value block 1 ->
1 2 3 4

NOTE: If something different is indicated on the display:
See Scan tool operating instructions.

- Read and record oxygen sensor factor in display field 3.
- Systematically spray parts of intake air system with engine leak detector spray.

If the engine speed drops or if oxygen sensor factor in display field 3 changes:

- Check for intake air system leaks in sprayed area and eliminate leak.