Operation CHARM: Car repair manuals for everyone.

Turbocharger: Testing and Inspection






Charge Air System, Checking for Leaks

Special tools, testers and auxiliary items required

Testing Unit for Turbocharger (V.A.G 1687)

End Seal (V.A.G 1687/5)

- Remove the noise insulation.

- Release the clip - A - and disconnect the charge air hose - B - from the charge air pipe.






- Install the end seal (V.A.G 1687/5) to charge air hose - A - and rotate it approximately 90° - B -.






Prepare the testing unit for turbocharger (V.A.G 1687) as follows:

- Turn the pressure regulator valve - 2 - counterclockwise until it stops.






- Close the valves - 3 and 4 -.

In order to be able to turn the pressure regulator valve - 2 -, the rotary knob must be pulled upward.

- Connect the testing unit for turbocharger (V.A.G 1687) as shown.






- Connect a pressurized air hose - 1 - to the testing unit for turbocharger (V.A.G 1687).






If water is located in the viewing glass, drain it via the water drain plug - 6 -.

- Open the valve - 3 -.

- Set the pressure to 0.5 bar using the pressure regulator valve - 2 -.


Pressure must not exceed 0.5 bar! A pressure set too high may damage the engine.

- Open the valve - 4 - and wait until the testing circuit has filled. If necessary, continue to regulate pressure to 0.5 bar.

- Check the charge air system for leaks by listening, feeling, using commercially available leak detection spray or by using the ultrasonic measuring device (V.A.G 1842).

Charge air hose connecting, refer to => [ Charge Air Hose, Disconnecting and Connecting ] Charge Air Hose, Disconnecting and Connecting.

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

Handling instructions of ultrasonic measuring device (V.A.G 1842). Refer to the operator's manual.

Before removing the end seal, discharge the pressure in the testing circuit by pulling off the coupling from the end seal (V.A.G 1687/5).

Hose connections and charge air system hoses must be free of oil and grease before installing.