Checking the Pressure Regulator

Checking the pressure regulator







WARNING: Be careful if the car is warm. The coolant is hot and there is a risk of burns from the intake manifold.

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

1 Undo the hose clip on the turbocharger delivery pipe and bend the bypass pipe aside.
2 Remove the exhaust manifold heat shield. The heat shield is attached with a nut and two clips on the underside.
3 Remove the three bolts securing the front exhaust pipe to the turbo unit.

Important
The flexible section at the front of the exhaust system should not bend out of line by more than 7 °C, i.e. if the front exhaust system is allowed to hang, it must not bend more than the sag caused by its own weight.

If the pipe is overloaded, permanent deformation of the components will result. This can cause noise and leakage, and damage at a later stage.







4 Remove the locking ring and unhook the pushrod from the valve operating arm.
5 Observe whether the flap valve abuts firmly against the turbine housing. Check for carbon deposits, etc.
6 Check that the arm moves easily.







7 Refit the locking ring and hook the pushrod on.







8 Attach the front exhaust pipe to the turbo. Grease the stud with Molykote 1000, part no. 30 20 271.
Tightening torque: 25 Nm (18.4 lbf ft)

Important
When fitting the front exhaust system to the turbo, the nuts should be tightened alternately to avoid distorting the flange. The flange must not abut against the turbo connection flange.

9 Mount the heat shield. Press on the left-hand clamp first. Coat the stud with Molykote 1000, part no. 30 20 971.
10 Mount the bypass valve with pipe. Fit a new O-ring, greased with non-acidic vaseline.
Tightening torque: 8 Nm (5.9 lbf ft)