Intake Air System, Checking For Leaks (False/Unmetered Air)
Intake air system, checking for leaks
Special tools and equipment
- VAG1551 or VAG1552 Scan Tool (ST) with VAG1551/3 adapter cable
- Engine leak detector spray G 001 800 A1
CAUTION! Part numbers are listed here for reference only. Always check with your Parts department for the latest information.
Checking conditions
- Engine coolant temperature at least 85 °C (185 °F) See VAG1551 scan tool function 08, display group 004, display field 3
Checking
NOTE:
- If there are leaks, in take manifold vacuum will draw in the leak detector spray with outside air. The spray reduces the ability of the fuel air mixture to ignite, which causes a drop in engine speed and a significant increase in CO-content.
- Observe the safety precautions listed on the container.
- Connect VAG1551 or VAG1552 scan tool and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (with engine running at idle), 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, and press -Q- button to confirm input.
Indicated on display
Read Measuring Value Block HELP
Input display group number XXX
- Press buttons -0-, -0- and -1- to input display group number 1(001), and press -Q- button to confirm input.
Indicated on display (1-4 = display fields)
Read Measuring Value Block ->
1 2 3 4
- Monitor oxygen sensor control in display fields 3 and 4.
Display Group 1:
- Systematically spray parts of intake system with engine leak detector spray.
If engine speed drops, or the values displayed for oxygen sensor control change:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06, and press -Q- button to confirm input.
- Switch ignition off.
- Check for leaks in area of intake air system most recently sprayed, and eliminate leaks.