Contents - Volkspage

4C.2 Emission control and exhaust systems
Exhaust systems
9 The exhaust system comprises the exhaust
manifold, a number of silencer units (depending
on model and specification), a catalytic
converter (where fitted), a number of mounting
brackets and a series of connecting pipes.
General information
1 The evaporative loss emission control
system consists of the purge valve, the
activated charcoal filter canister and a series
of connecting vacuum hoses.
2 The purge valve is mounted on a bracket
behind the air cleaner housing, and the
charcoal canister is mounted on a bracket
above the right hand front wheel housing.
Purge valve
3 On single-point injection models, ensure
that the ignition is switched off, then unplug
the wiring harness from the purge valve at the
connector.
4 Slacken the clips and pull the vacuum
(where applicable) and vapour hoses off the
purge valve ports. Make a note of their
orientation to aid refitting later. Remove the
valve from the engine bay (see illustration).
5 Refitting is a reversal of removal.
Charcoal canister
6 Open the bonnet and locate the canister in
the right hand wing (see illustration).
Disconnect the vapour hoses from it and
make a note of their order of connection to aid
correct refitting later.
7 Remove the screws from the securing
bracket and lift the canister out of its aperture.
8 Refitting is a reversal of removal.
3 Crankcase emission system
- general information
The crankcase emission control system
consists of a series of hoses that connect the
crankcase vent to the camshaft cover vent
and the air inlet, a pressure regulating valve
(where applicable) and an oil separator unit.
The components of this system require no
attention other than to check at regular
intervals that the hose(s) are free of blockages
and undamaged.
The exhaust manifold removal is described
as part of the cylinder head dismantling
sequence; refer to Chapter 2A.
General information
1 The exhaust system is made up of the
downpipe, (with integral catalytic converter,
where fitted), the intermediate pipe and the
tail section which contains the rear silencer.
2 On all models, the system is suspended
throughout its entire length by rubber
mountings, which are secured to the
underside of the vehicle by metal brackets.
Removal
3 Each exhaust section can be removed
individually or, alternatively, the complete
system can be removed as a unit.
4 To remove the system or part of the
system, first jack up the front or rear of the car
and support it on axle stands (see “Jacking
and vehicle support”). Alternatively position
the car over an inspection pit or on car ramps.
Downpipe
5 Place blocks of wood under the catalytic
converter/front silencer to act as a support.
Where applicable, refer to Chapter 4A or B
and remove the Lambda sensor from the
exhaust pipe.
6 Slacken the clamp and separate the down
pipe from the intermediate pipe.
7 Undo the nuts and separate the downpipe
from the exhaust manifold. Recover the
gasket.
2.4 Purge valve location - 2.6 Charcoal canister location -
engine code 3F shown
engine code 3F shown
Catalytic converter
8 Where fitted, the catalytic converter is
integral with the down pipe.
Intermediate pipe
9 Slacken the clamping ring bolts and
disengage the clamp from the intermediate
pipe-to-tailpipe joint and the intermediate
pipe-to-catalytic converter/front silencer joint.
10 Disengage the intermediate pipe from the
tailpipe and the catalytic converter/front
silencer and remove it from underneath the
vehicle.
Tailpipe
11 Slacken the clamping ring bolts and
disengage the tailpipe at the joint.
12 Unhook the tailpipe from its mounting
rubbers and remove it from the vehicle.
Complete system
13 Disconnect the down pipe from the
manifold as described earlier in this Section.
14 With the aid of an assistant, free the
system from all its mounting rubbers and
manoeuvre it out from underneath the vehicle.
Heatshields
15 The heatshields, where fitted, are secured
to the underside of the body by a combination
of nuts, bolts and clips. Each shield can be
removed once the relevant exhaust section
has been removed. Note that if the shield is
being removed to gain access to a
component located behind it, in some cases it
may prove sufficient to remove the retaining
nuts and/or bolts and simply lower the shield,
removing the need to disturb the exhaust
system.
Refitting
16 Each section is refitted by a reverse of the
removal sequence, noting the following
points.
a) Ensure that all traces of corrosion have
been removed from the flanges and
renew all necessary gaskets.
b) inspect the rubber mountings for signs of
damage or deterioration and renew as
necessary.
c) On joints which are secured by clamping
rings, apply a smear of exhaust system
jointing paste to the joint mating surfaces
to ensure an air-tight seal. Tighten the
clamping ring nuts evenly and
progressively to the specified torque so
that the clearance between the clamp
halves is equal on either side.
d) Prior to tightening the exhaust system
fastenets, ensure that all rubber
mountings are correctly located and that
there is adequate clearance between the
exhaust system and vehicle underbody.