Volkswagen Workshop Service and Repair Manuals

Checking charge air system for leaks Special tools and workshop equipment required

t  Charge air system tester -V.A.G 1687- with adapter -V.A.G 1687/12- Procedure –  Remove engine cover panel → Chapter.

–  Remove crankcase breather hose -1- from cylinder head cover. To do this, press release buttons. –  Expose vacuum hoses -arrows- at air pipe. –  Release hose clips -3- and remove air hose from air filter housing. –  Unscrew bolt -2-, swing air pipe with inlet connection to rear and pull off from turbocharger.

–  Remove bolts -arrows-. –  Undo hose clip -1- and remove the pulsation damper -2-.

–  Insert adapter -1687/12- into intake hose -1- and secure with a clip. Prepare charge air system tester -V.A.G 1687- as follows:

–  Unscrew pressure control valve -2- completely and close valves -3- and -4-.   Note To turn the pressure regulating valve -2- the knob must be pulled upwards.

–  Connect charge air system tester -V.A.G 1687- to adapter -1687/12- as shown.

–  Connect compressed air hose -1- (compressed air supply) to charge air system tester -V.A.G 1687-.   Note If there is water in inspection glass, drain via drain screw -6-. –  Open valve -3-. –  Set pressure to 0.5 bar at pressure control valve -2-.   Caution 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 test circuit is full. If necessary, regulate pressure to 0.5 bar. –  Check charge-air system for leaks by: t  listening t  feeling t  using standard leak detecting spray t  Ultrasonic tester -V.A.G 1842-   Note t  Slight leaks on the intake side of turbocharger are permissible, as the intake hoses are not designed for high-pressure. t  A small amount of air escapes through the valves and enters the engine. Therefore a holding pressure test is not possible. t  How to use the ultrasonic tester -V.A.G 1842- → operating instructions t  If a leak has been located, observe notes for charge air system when carrying out any repair work. t  Depressurise test circuit by detaching coupling from adapter -1687/10- before removing adapter. Reassembly Installation is carried out in the reverse order; note the following:   Note t  Renew the seal and O-ring. t  Hose connections and air intake pipes/hoses must be free of oil and grease when installing. t  Secure hose connections with hose clips corresponding to the series equipment → Electronic parts catalogue. –  Installing inlet connection and pulsation damper → Chapter. –  Installing intake hoses with screw-type clips → Chapter.