Charge air control valve: Checking

If the basic boost pressure cannot be adjusted, check as follows:

1. Unhook the exhaust pipe bend from the turbocharger and visually check the flap valve's contact with the turbine housing.
   Fig 1: Unhooking Exhaust Pipe

   
2. Break the seal, remove the circlip and unhook the pushrod from the valve's operating arm.
3. Check that the arm moves easily.

   Change the control valve if it is defective.

4. Refit the circlip and affix a seal to the pushrod.