Checking charge air system for leaks — VW

🧭 Before you start

Fits: VW Touran I (1T, 2003–2015), VW Golf V / Jetta (1K, 2003–2009), VW Tiguan I (5N, 2007–2016); platform code 5M1

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• Crankcase breather hose must be pulled off during leak test to prevent damage to engine. — Seal intake connecting pipe with a bung from engine bung setVAS 6122.
• If there is water in the sight glass, drain at water drain screw (6).
• The pressure must not exceed 0.5 bar! If the pressure is too high this can cause damage to the engine. — Open valve (4) and wait until the test circuit is filled. If necessary readjust pressure to 0.5 bar.
• Ensure that the vacuum hose is locked onto the union (2).

🔧 Engine codes this applies to

📐 36 workshop diagrams for ADR

Real factory drawings for this job — timing marks, bolt locations and routing. Locked in the free view.

📋 Procedure

1. Release vacuum hose on vacuum reservoir (arrow) and pull it off.
2. Lift engine cover panel at points (1) and pull it forwards in direction of (arrow).
3. Pull vacuum hose off (arrow).
4. Lift engine cover panel at points (1) and pull it forwards in direction of (arrow).
5. Press hose locking mechanism and pull hose for crankcase breather (1) off intake connecting pipe.

6. Also pull crankcase breather hose off valve timing housing.
7. ⚠ Crankcase breather hose must be pulled off during leak test to prevent damage to engine. — Seal intake connecting pipe with a bung from engine bung setVAS 6122.
8. Remove spring-type clips (2) from intake hose and remove intake hose.
9. Renew spring-type clips (arrows) with screw-type clips from charge air system testerV.A.G 1687.
10. Slide adapterV.A.G 1687/6 into intake hose (2) and secure hose to intake connecting pipe with screw-type clips (1) from charge air system testerV.A.G 1687.
11. Unscrew pressure regulating valve (2) and close valves (3) and (4).
12. Connect charge air system testerV.A.G 1687 as shown.
13. Connect pressure hose (1) (compressed air supply) to charge air system testerV.A.G 1687. [Note: If there is water in the sight glass, drain at water drain screw (6).]
14. Open valve (3).
15. Adjust pressure to 0.5 bar with pressure regulating valve (2).
16. ⚠ The pressure must not exceed 0.5 bar! If the pressure is too high this can cause damage to the engine. — Open valve (4) and wait until the test circuit is filled. If necessary readjust pressure to 0.5 bar.
17. Check the charge air system for leaks by hearing, touching, with commercially available leak detector spray or using ultrasonic testerV.A.G 1842. [Note: Slight leaks in the area of the intake connecting pipe (arrows) are permissible, as the intake hoses are not designed for high-pressure.A small amount of air escapes through the valves and enters the engine. Therefore a holding pressure test is not possible.How to use the ultrasonic testerV.A.G 1842operating instructionsDepressurise test circuit by detaching coupling from adapterV.A.G 1687/6 before removing adapter.Hose connections and hoses must be free of oil and grease before assembly.After testing compression, secure intake hoses again with spring-type clips.]
18. Place vacuum hose (2) onto vacuum reservoir union (1). [Note: Ensure that the vacuum hose is locked onto the union (2).]
19. Push engine cover panel down at points (1) in direction of (arrow) until it engages.
20. Push engine cover panel down at points (1) in direction of (arrow) until it engages.
21. Fit vacuum hose onto connection (arrow).

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