Checking charge air system for leaks, vehicles with two turbochargers — AUDI

🧭 Before you start

Fits: Audi A6/A7 C7 (4G, 2011–2018)

• Special tools named: V.A.G 1687/18, V.A.G 1687, V.A.G 1842
• Renewed: gasket
• Also covered elsewhere: Operating instructions

Don't miss

• If there is water in sight glass, remove drain plug (6) and drain water.
• Risk of damage if pressure is set too high.The pressure must not exceed 0.5 bar. — Adjust pressure to 0.5 bar via pressure control valve (2).

🔧 Engine codes this applies to

📋 Procedure

1. Remove engine cover panel .
2. Release hose clips (arrows) and remove air pipe (1).
3. Press release tabs and disconnect crankcase breather hose (1) from connection(2).
4. Remove bolts (arrows) and detach connection from turbocharger.
5. Connect adapter V.A.G 1687/18-1 with V.A.G 1687/18-2 to turbocharger.

6. Release hose clip (arrow) and detach air hose.
7. Connect adapter1687/11 to air hose going to throttle valve module J338.
8. Connect hose (1) of charge air system tester V.A.G 1687 to adapter.
9. Unscrew pressure control valve (2) completely and close valves (3) and (4).
10. Using a commercially available connection piece, connect charge air system testerV.A.G 1687 to compressed air (1). [Note: If there is water in sight glass, remove drain plug (6) and drain water.]
11. Open valve (3).
12. ⚠ Risk of damage if pressure is set too high.The pressure must not exceed 0.5 bar. — Adjust pressure to 0.5 bar via pressure control valve (2).
13. Open valve (4) and wait until test system is pressurised. If necessary, adjust pressure to 0.5 bar again.
14. Check charge air system for audible leaks or leaks that can be felt with the hand; apply commercially available leak detecting spray or use ultrasonic testerV.A.G 1842. [Note: A small amount of air escapes through the valves and enters the engine. Therefore it is not possible to perform a pressure retention test.For operation of ultrasonic tester V.A.G 1842, refer to Operating instructions.Release pressure in test circuit by detaching hose coupling from adapter before removing adapter.] [Note: Renew gasket and O-rings.]

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