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
inlet air on the way to the inlet manifold.
3 Boost pressure (the pressure in the inlet
manifold) is limited by a wastegate, which
diverts the exhaust gas away from the turbine
wheel in response to a pressure-sensitive
actuator.
4 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
5 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.
6 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.
7 Do not race the engine immediately after
start-up, especially if it is cold. Give the oil a
few seconds to circulate.
8 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.
9 Allow the engine to idle for several minutes
before switching off after a high-speed run.
10 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.
14 Turbocharger -
removal and refitting
1
Removal
1 Disconnect the battery negative (earth) lead
(refer to Chapter 5, Section 1).
2 Drain the cooling system as described in
Chapter 1.
3 Remove the air cleaner complete with
airflow meter assembly as described in
Section 2.
4 Undo the bolts and remove the heat shield
behind the alternator.
5 Slacken the two clips and remove the oil
return hose at the base of the turbocharger.
6 Slacken the two hose clips and remove air
the outlet hose from the turbocharger.
7 Disconnect the vacuum hose at the
wastegate solenoid valve.
8 Disconnect the oil feed pipe unions at the
turbocharger.
9 Disconnect the coolant feed and return
hoses at the turbocharger and engine pipe
outlets.
10 Remove the engine oil dipstick and
release the dipstick tube from its upper
attachments.
11 Release the hose clips and support
brackets and remove the coolant pipe over
the top of the exhaust manifold.
12 Disconnect the wiring multiplug connector
above the alternator and release the cable
harness from its clips.
13 Disconnect the wastegate control
solenoid wiring.
14 Undo the three nuts and separate the
exhaust downpipe from the turbocharger
outlet flange.
15 Undo the exhaust manifold retaining nuts
and withdraw the manifold complete with
turbocharger assembly off the studs. Recover
the manifold gasket.
16 Undo the nuts securing the turbocharger
to the exhaust manifold and remove the
turbocharger. Recover the flange gasket .
17 Thoroughly clean all the joint mating faces
prior to refitting.
Refitting
18 Refitting is a reversal of removal, but use
new gaskets at all the flange joints. Refill the
cooling system and top-up the engine oil as
described in Chapter 1 on completion.
15 Turbocharger -
examination and renovation
2
1 With the turbocharger removed, inspect the
housing for cracks or other visible damage.
2 Spin the turbine or the compressor wheel,
to verify that the shaft is intact and to feel for
excessive shake or roughness. Some play is
normal, since in use, the shaft is “floating” on
a film of oil. Check that the wheel vanes are
undamaged.
3 If the exhaust or induction passages are oil-
contaminated, the turbo shaft oil seals have
probably failed.
4 No DIY repair of the turbo is possible. A
new unit may be available on an exchange
basis.
16 Exhaust system - general
information and component
renewal
Refer to Part A, Section 13 and, on vehicles
equipped with a catalytic converter, to Part E,
Section 3.
4B•8 Fuel and exhaust systems - Lucas multi-point injection engines
1380 Rover 800 Series Remake
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