Intercooler: Testing and Inspection

Charge Air System, Checking for Leaks

Special tools, testers and auxiliary items required

• Adapter (V.A.G 1687/5)

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

• Ultrasonic Measuring Device (V.A.G 1842)

Test Sequence:

- Remove the noise insulation.

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






- Connect the adapter (V.A.G 1687/5) to the charge air hose - A - and rotate it around 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 the compressed air line - 1 - (pressurized air supply) to the testing unit for turbocharger (V.A.G 1687).






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

- Open the valve - 3 -.

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


The 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 poorly sealed areas by listening, feeling, using commercially available leak detection spray or by using the ultrasonic measuring device (V.A.G 1842).

• Charge air hose connecting and disconnecting, Refer to => [ Charge Air Hose and Pipe, Disconnecting and Connecting ] Charge Air Hose and Pipe, Disconnecting and Connecting.

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

• Handling instructions for the ultrasonic measuring device (V.A.G 1842). Refer to the tools operating manual.

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

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