Mechanical Recirculating Valve, Checking

Mechanical Recirculating Valve, Checking

• The mechanical recirculating valve is located in front of the turbocharger. It is opened by a vacuum via the Turbocharger Recirculating Valve (N249) during deceleration, idle and partial throttle. This decreases the charge pressure in front of the throttle valve. This keeps the turbocharger running at a higher speed.

• Check the recirculating valve if there is a lack of performance or sudden throttle changes.

Special tools, testers and auxiliary items required

• Hand Vacuum Pump (V.A.G 1390)

Test Sequence

- Connect the Hand Vacuum Pump (V.A.G 1390 ) to the recirculating valve.

- Operate hand vacuum pump.

• The recirculating valve must open - arrow -.





- After about 30 seconds, activate vacuum pump ventilation valve.

• The recirculating valve must close - arrow -.

If recirculating valve does not open or close or if valve plate is not properly sealed when recirculating valve is closed:

- Replace the recirculating valve and secure the hose connections with hose clamps.