Checking & Adjusting Basic Charging Pressure: 9-3
- Remove the bypass pipe with valve.NOTE: There is an "O" ring where the bypass pipe is fastened to the turbocharger inlet pipe.
- Remove the exhaust manifold heat shield. The heat shield is fastened with a nut and two clips underneath. See Fig 1.
- Remove the circlip from the operating arm using Circlip tool (83 94 538).
- Hold the pushrod with pliers. Undo the lock nut. See Fig 2.
- Hold the operating arm and detach the pushrod. Secure the arm. Otherwise, the operating arm may "jump over".
- Move the operating arm on the boost pressure control valve towards "Closed" and adjust the end piece so that the pushrod fits easily on the operating arm pin.
- Detach the pushrod from the control arm pin. Turn the end piece clockwise approx. 2 turns so that a 2 mm tension is achieved. Hook on the pushrod to the operating arm pin. Fit the locking ring.
- Detach the hose from the diaphragm box.
- Connect Pressure/Vacuum Pump (30 14 883) to the diaphragm unit and Charge Pressure Gauge (83 93 514). See Fig 3.
- Carefully pump up pressure until the control rod moves to regulate the boost pressure.
- Just as the control rod starts to move, read off the pressure on the pressure gauge. It should be 0.42-0.48 bar.
- Shorten the rod if the pressure is too low until 0.45 bar is obtained.
- Undo the pushrod and apply Molycote 1000, or equivalent to the pin on the operating arm. See Fig 4.
- Fit the pushrod and clip, grip the pushrod with a pair of adjustable pliers and lock the nut.
- Remove the pressure gauge and pump.
- Reconnect the hose to the diaphragm box.
- Fit the heat shield. See Fig 5.
- Lubricate the "O" ring with acid-free petroleum jelly and fit the bypass pipe.