Intercooler; Turbocharger; Exhaust Manifold And Turbocharger - Opel Zafira B MPV 2006 Owners Workshop Manual

48•14 Fuel and exhaust systems - diesel engines
Removal
1 Disconnect the battery negative terminal
(refer to Disconnecting the battery in the
Reference Chapter).
2 Remove the plastic cover from the top of
the engine.
3 Remove the radiator as described in
Chapter 3.
4 Slacken the retaining clip, undo the
mounting bolt and remove the charge air pipe
from the top of the intercooler.
5 Undo the two retaining nuts and lift the
auxiliary cooling fan off the intercooler
bracket.
6 Undo the three bolts securing the intercooler
to the radiator.
7 Unclip the charge air pipe from the radiator
bracket and remove the intercooler from the
radiator.
Refitting
8 Refitting is the reverse of removal.
18 Turbocharger-
descr!ption precautions
1 The turbocharger increases engine efficiency
by raising the pressure in the intake manifold
above atmospheric pressure. Instead of the
air simply being sucked into the cylinders, it is
forced in.
2 Energy for the operation of the turbocharger
comes from the exhaust gas. The gas flows
through a specially-shaped housing (the
turbine housing) and, in so doing, spins the
turbine wheel. The turbine wheel is attached to
a shaft, at the end of which is another vaned
wheel known as the compressor wheel. The
compressor wheel spins in its own housing,
and compresses the intake air on the way to
the intake manifold.
3 The turbocharger operates on the principle
19.Sa Undo the two bolts {arrowed) each
side ..•
19.7 Insert a drill bit (arrowed} or similar,
through the holes provided on the radiator
mounting brackets (shown with radiator
removed)
of variable vane geometry. At low engine
speeds the vanes close to give less flow
cross-section, then as the speed increases the
vanes open to give an increased flow cross-
section. This helps improve the efficiency of
the turbocharger.
4 Boost pressure (the pressure in the intake
manifold) is limited by a wastegate, which
diverts the exhaust gas away from the turbine
wheel in response to a pressure-sensitive
actuator.
5 The turbo shaft is pressure-lubricated by
an oil feed pipe from the main oil gallery. The
shaft 'floats' on a cushion of oil. A drain pipe
returns the oil to the sump.
Precautions
6 The turbocharger operates at extremely high
speeds and temperatures. Certain precautions
must be observed, to avoid premature failure
of the turbo, or injury to the operator.
Do not operate the turbo with any of its parts
exposed, or with any of its hoses removed.
Foreign objects falling onto the rotating
vanes could cause excessive damage, and (if
ejected) personal injury.
• Do not race the engine immediately after
start-up, especially if it is cold. Give the oil a
few seconds to circulate.
., Always allow the engine to return to idle
speed before switching it off - do not blip the
throttle and switch off, as this will leave the
turbo spinning without lubrication.
• Allow the engine to idle for several minutes
before switching off after a high-speed run.
19.Sb ... and remove the radiator
mounting brackets, noting their orientation
• Observe the recommended intervals for
oil and filter changing, and use a reputable
oil of the specified quality. Neglect of oil
changing, or use of inferior oil, can cause
carbon formation on the turbo shaft, leading
to subsequent failure.
Note: New manifold retaining nuts, new
gaskets for all disturbed joints, and new
copper washers for the turbocharger oil supply
pipe banjo union will be required for refitting.
Removal
1 Disconnect the battery negative terminal
(refer to Disconnecting the battery in the
Reference Chapter).
2 Remove the plastic cover from the top of
the engine.
3 Firmly apply the handbrake, then jack up
the front of the car and support it securely on
axle stands (see Jacking and vehicle support).
4 Drain the cooling system as described in
Chapter 18.
5 On models equipped with air conditioning,
remove the auxiliary drivebelt as described in
Chapter 18.
Automatic transmission models
6 Remove the front bumper as described in
Chapter 11.
7 Retain the radiator in position by inserting
a drill bit or similar through the holes provided
on each of the radiator upper mounting
brackets (see illustration).
8 Undo the two bolts each side securing
the radiator left-hand and right-hand
mounting brackets to the subframe. Remove
the brackets, noting their orientation {see
illustrations).
9 Taking care to avoid damaging the attached
parts and surrounding components, pull the
radiator assembly forward at the bottom and
retain it in that position by inserting a suitable
block of wood between the base of the
radiator and the subframe.
10 Undo the bolt and remove the clamp
securing the fluid cooler pipes to the front of
the engine mounting.
All models
11 Remove the exhaust system front pipe as
described in Section 20.
12 Remove the air cleaner assembly and air
intake duct as described in Section 3.
13 On DOHC (Z19DTH) engines, release the
retaining clip securing the engine breather
hose to the breather pipe adjacent to the
engine oil dipstick. Undo the two bolts
securing the breather pipe to the cylinder
head, and disconnect the pipe from the hose
(see illustration 14.30).
14 Unclip the vacuum hose from the engine
oil dipstick guide tube, then undo the bolt and
remove the dipstick guide tube.