Charge Air System, Checking For Leaks

WARNING: This page is about a different car, the 2024 Audi Q7 and 2023 Audi Q7. However, it is still accessible from the selected car via links, so may be relevant.

Special tools and workshop equipment required

Turbo System Tester Kit:VAG1687

Fig 1: Identifying Turbo System Tester Kit
Courtesy of AUDI
Turbo System Tester Kit - Adapter 6:VAG1687/6

Fig 2: Identifying Turbo System Tester Kit
Courtesy of AUDI
Ultrasonic Tester:VAG1842S , not illustrated
Leak detection spray, commercially available

Procedure

-- Pay attention to the guidelines for clean working conditions. Refer to GUIDELINES FOR CLEAN WORKING CONDITIONS .

-- Remove the air filter housing. Refer to AIR FILTER HOUSING, REMOVING AND INSTALLING .

-- Connect the Turbo System Tester Kit - Adapter 6:VAG1687/6 -1- to the air duct hose.

Courtesy of AUDI

-- Connect the hose -arrow- from the Turbo System Tester Kit:VAG1687 to the adapter.

Prepare the Turbo System Tester Kit:VAG1687 as follows:

Fig 3: Connecting Pressurized Air Hose To Testing Unit For Turbo Charger V.A.G 1687

Courtesy of AUDI

-- Completely remove the pressure regulating valve -2- and close the valves -3 and 4-.

The knob must face upward so the pressure regulating valve can be turned.

-- Connect the Turbo System Tester Kit:VAG1687 to compressed air -1- with a commercially available intermediate piece.

-- Drain the water in the viewing glass via the water drain plug -6-.

-- Open the valve -3-.

CAUTION:

There is a risk of damage if the pressure is set too high.

- The pressure must not exceed 0.2 bar (2.9 psi).

-- Set the pressure to 0.2 bar (2.9 psi) using the pressure regulating valve -2-.

-- Open the valve -4- and wait until the test circuit is filled. Regulate the pressure back to 0.2 bar (2.9 psi), if necessary.

-- Listen, feel and use commercially available leak detection spray or the Ultrasonic Measuring Device:VAG1842 to check the charge air system for leaks. Refer to the appropriate Service Information.

TIP:

A small quantity of air dissipates via the valves in the engine. For this reason a pressure retention test is not possible.

-- Release the pressure in the test circuit by removing the hose coupling before removing the adapter.

Assembling

Assemble in the reverse order of removal. Note the following:

Replace the seal and O-ring after removal.
Secure all hose connections with hose clamps that match the ones used in series production. Refer to the appropriate Electronic Parts Information.

-- Install the air filter housing. Refer to AIR FILTER HOUSING, REMOVING AND INSTALLING .

Tightening Specifications

Refer to OVERVIEW - CHARGE AIR HOSE CONNECTIONS .