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:V.A.G 1687

Fig 1: Identifying Turbo System Tester Kit
Courtesy of AUDI
Turbo System Tester Kit - Adapter 6:V.A.G 1687/6 and the Adapters :V.A.G 1687/3 , :V.A.G 1687/13-2 , :V.A.G 1687/15

Fig 2: Identifying Turbo System Tester Kit
Courtesy of AUDI

Procedure

Follow the guidelines for clean working conditions. Refer to GUIDELINES FOR CLEAN WORKING CONDITIONS .

All except Audi Q7/Q8:

-- Remove the engine cover. Refer to ENGINE COVER, REMOVING AND INSTALLING .

-- Remove the lock carrier cover. Refer to OVERVIEW - BUMPER COVER .

Audi A4/A5:

Courtesy of AUDI

-- Remove the bolts -arrows- and the air guide -2-.

-- Loosen the hose clamps -arrows-.

Courtesy of AUDI

-- Remove the vacuum hose -2- at the same time to not damage it.

-- Remove the air duct pipe -1-.

Audi A6/A7:

Courtesy of AUDI

-- Remove the bolts -arrows- and then remove the air guides -1 and 2-.

-- If installed, press the release buttons on both sides and remove the secondary air injection hose -arrow- (example illustration).

Courtesy of AUDI

-- Disengage the EVAP system hose -1- with the fuel hose.

Courtesy of AUDI

-- Loosen the hose clamps -arrows-.

-- Remove the vacuum hose -2- and air duct pipe -1-.

Audi A8:

Courtesy of AUDI

-- Free up the EVAP system hose -3- from the air duct pipe.

-- Remove the vacuum hose -4- without damaging it.

-- Press the release buttons on both sides and remove the secondary air injection pipe -5-.

-- Loosen the hose clamps -2 and 6- and remove the air duct hose.

Audi Q5:

Courtesy of AUDI

-- Remove the bolts -arrows- and air duct -1-.

-- Remove the vacuum hose -2- at the same time to not damage it.

Courtesy of AUDI

-- If installed, press the release buttons on both sides and remove the secondary air injection hose -3-.

-- Loosen the hose clamps -arrows- and remove the air duct pipe -1-.

Audi Q7/Q8:

Courtesy of AUDI

-- Remove the air filter upper section. Refer to AIR FILTER HOUSING, REMOVING AND INSTALLING, AUDI Q7/Q8 .

-- Remove the cap -2-.

-- Release the retainer -arrow B- and remove the oil filler tube -1- upward from the air filter lower section.

-- Turn the oil filler tube counter-clockwise -arrow A- and remove it.

-- Close the oil filler tube with the cap.

-- Loosen the hose clamp -arrow- and remove the air duct pipe from the air filter housing.

Courtesy of AUDI

-- Free up the EVAP system hose -2- from the air duct pipe.

Fig 3: Fuel Tank Pressure Sensor 2 -G850- Component Location

Courtesy of AUDI

-- Remove the vacuum hose -3-.

Courtesy of AUDI

-- Press the release buttons on both sides and remove the secondary air injection hose -4-.

-- Loosen the hose clamp -1- and remove the air duct pipe -2-.

Continuation for All Vehicles:

Courtesy of AUDI

-- Install the Turbo System Tester Kit - End Seal:V.A.G 1687/6 and Turbo System Tester Kit - Adapter:V.A.G 1687/13-2 on the turbocharger.

CAUTION:

Risk of damaging the coupling due to improper handling.

- Coupling must not be bent more than 10°.

- Do not load the coupling on the cable.

-- Loosen the front clamping sleeve -arrows- and push toward the rear.

Fig 4: Identifying Bolts

Courtesy of AUDI

-- Slightly lower the front muffler -2- and secure as shown with a cable tie -1-.

Courtesy of AUDI

-- Seal the front muffler with Turbo System Tester Kit - Adapter:V.A.G 1687/3 and Turbo System Tester Kit - Adapter:V.A.G 1687/15 .

Courtesy of AUDI

-- Connect the Turbo System Tester Kit:V.A.G 1687 to the Turbo System Tester Kit - Adapter 6:V.A.G 1687/6 using the connection -5-.

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

Courtesy of AUDI

Pull the knob in order to rotate the pressure regulating valve -2-.

-- Connect the Turbo System Tester Kit:V.A.G 1687 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:

Risk of damaging the components if the pressure is set too high.

- Never set the test pressure above the specified adjustment.

-- 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 to 0.2 bar (2.9 psi) again if necessary.

-- Check the charge air system for leaks by listening, feeling and using commercially available leak detection spray or the Ultrasonic Tester:V.A.G 1842S .

A small quantity of air dissipates via the valves in the engine. For this reason a pressure retention test is not possible.
Refer to the appropriate Operating Instructions for information on using the Ultrasonic Tester:V.A.G 1842S .

Assembling

Assembly is performed in reverse order.

Release the pressure in the test circuit by pulling off the coupling before removing the adapter.
Secure all hose connections with hose clamps that match the ones used in series production. Refer to the appropriate Electronic Parts Information.

-- Install the lock carrier cover. Refer to OVERVIEW - BUMPER COVER .

-- Install the air filter upper section. Refer to AIR FILTER HOUSING, REMOVING AND INSTALLING, AUDI Q7/Q8 .

-- Install the engine cover. Refer to ENGINE COVER, REMOVING AND INSTALLING .

Tightening Specifications

Refer to OVERVIEW - AIR FILTER HOUSING
Refer to OVERVIEW - MUFFLER
Refer to OVERVIEW - CHARGE AIR HOSE CONNECTIONS