Turbocharging system — general information (VW Passat B4)

The boost is provided by a turbocharger operating on exhaust gases. On vehicles with "RA" and "SB" engines, the boost air is cooled in an air-to-air heat exchanger.

The "RA" and "SB" engines use a Garett turbocharger of the TZ type, and the "AAZ" engines use a KKK type.

Boost pressure:

• engines "RA" and "SB" 0.64-0.83 kgf/cm²;
• engines "AAZ" 0.60-0.83 kgf/cm².

The turbocharging system of the "RA" and "SB" engines includes a pressure reducing valve. Opening pressure is 0.85+0.05 kgf/cm².

Warning: When working on the turbocharger, strictly adhere to the following requirements:

• before removing parts, thoroughly clean their joints and surrounding surfaces;
• place the removed parts on a clean surface and cover them with film;
• carefully close and seal the exposed internal cavities of the parts if the repair is not carried out immediately after opening;
• clean parts thoroughly before assembly;
• open the packaging of the spare parts to be installed only immediately before their installation;
• do not use parts that have been stored without original packaging;
• after opening the turbocharger, do not use compressed air to clean parts and do not move the vehicle.

[The original text is available on the website VWmanual]