Checking Intake Air System For Leaks (Unmetered or False Air)

Special tools and equipment







- VAS5051 with VAG 5051/1
or
- VAG 1551 with VAG 1551/3A
- Engine leak detection spray G 001 800 A1


NOTE:
- Leak detection spray is drawn into intake system along with un-metered air by vacuum in intake system. Leak detection spray decreases ignition quality and performance of the fuel mixture. This causes a reduction in engine speed and a sharp increase of CO content.
- Always observe the safety precautions printed on can.


Test sequence
- Connect VAS5051 tester or VAG 1551 scan tool and select control module for engine electronics using "address word" 01.
- Engine must run at idle for this.

When indicated on display:


Rapid data transfer HELP
Select function XX


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

When indicated on display:


Read Measuring Value Block number Q
Input display group number XXX


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

Indicated on display: (1 - 4 = display fields)


Read Measuring Value Block 1 ->
1 2 3 4


- Note engine speed in display field 1.
- Systematically spray parts of intake system with engine leak detection spray.

If engine speed does not change:
- Press -> button.

Indicated on display (function selection):


Rapid data transfer HELP
Select function XX


If engine speed decreases:
- Press -> button.
- Press buttons -0- and -6- to select "End output" and press -Q- button to confirm input.
- Switch ignition off.
- Check sprayed portions of intake system for leaks and repair malfunction.