Intake Air System, Checking For Leaks (False/Unmetered Air)

Intake Air System, Leak Checking

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required
- VAG 1551/1552 Scan Tool with VAG 1551/3 Adaptor cable
- G 001 800 A1 Engine leak detector spray

Requirements
- Engine Coolant Temperature 85 °C minimum.

Test sequence


NOTE:
- Intake system vacuum will cause the leak detector spray to be drawn in along with any unmeasured air. Leak detector spray reduces the ignitability of the mixture leading to a drop in engine speed and a change in the Oxygen sensor reading.
- Always observe safety precautions listed on the container.


- Connect VAG 1551/1552 Scan Tool.
- Start engine and let idle.
- Press 0 and 1 buttons to select "Engine Electronics" address word 01.

Indicated on display (example only)


06A906018AB Motronic M5.9.2 HS V06 ->
Coding 00000 WSC 00000


- Press -> button.

Indicated on display


Rapid data transfer HELP
Select function XX


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

Indicated on display


Read measuring value block
Input Display group number XXX


- Press 0, 0 and 1 buttons to select "Display group 1"
- Press Q button to enter input.

Indicated on display (1 to 4 = Display fields)


Read measuring value block 1 ->
1 2 3 4


- Check if Engine Coolant Temperature is above 85 °C in Display field 2.
- Note Oxygen control in Display fields 3 and 4.







- Systematically spray the intake system components with engine leak detector spray.

If engine speed drops or the Oxygen sensor control displayed value changes
- Press -> button.

Indicated on display


Rapid data transfer HELP
Select function XX


- Press 0 and 6 buttons to select "End output" function 06.
- Press Q button to enter input.
- Switch OFF ignition.
- Check sprayed areas of intake system for leaks and correct as necessary.