Charge Air System, Checking for Leaks

Charge Air System, Checking for Leaks

Special tools, testers and auxiliary items required

• Testing Unit for Turbocharger (V.A.G 1687) with Adapter (V.A.G 1687/10)

• Ultrasonic Measuring Device (V.A.G 1842) , commercially available leak detection spray


• Follow the safety precautions when working on the charge air system and turbocharger. Refer to => [ Safety Precautions ] Safety Precautions.

• Observe the rules for cleanliness. Refer to => [ Clean Working Conditions ] Clean Working Conditions.

Always follow these instructions before and during work.

Test Sequence

- Disconnect the intake tube - 1 - from the Mass Airflow (MAF) sensor. Loosen the hose clamps using hose clip pliers (VAS 6362).






- Place the adapter (V.A.G 1687/10) in the intake tube - 1 - and secure it with a clamp.

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

- Unscrew the pressure regulator valve - 2 - completely and close 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) to the adapter (V.A.G 1687/10) as shown.






- Connect the pressurized air hose - 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 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 test circuit is filled. Adjust the pressure to 0.5 bar if necessary.

- 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 cooler hose disconnecting and connecting. Refer to => [ Charge Air Cooler Hose, Disconnecting and Connecting ] Service and Repair.

• Small leaks on the intake side of the turbocharger are permitted because the intake hoses are not designed for positive pressure.

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

• For handling instructions of the ultrasonic measuring device (V.A.G 1842). Refer to the tools owners manual.

• If a poorly sealed area is discovered, observe the notes for the charge air system when repairing. Refer to => [ Charge Air System ] Charge Air System.

• Before removing the adapter, discharge the pressure in the testing circuit by pulling off the hose from the adapter (V.A.G 1687/10).