48Turn the crankshaft clockwise until the
TDC marks on the camshaft sprockets are
aligned with the notches in the camshaft
cover, and check that the crankshaft pulley
TDC mark is aligned with the pointer on the
rear timing belt cover.
49Proceed as described in paragraphs 30 to
34 inclusive.
5Timing belt, with automatic
adjuster- removal, refitting
and adjustment
3
Removal
1The operations are essentially the same as
described in Section 4, except that the
tensioner pulley incorporates an automatic
adjuster that simplifies the procedure as
follows.
2To release the belt tension before removal,
unscrew the timing belt tensioner pulley
securing bolt slightly then, with a large
screwdriver (or similar tool) inserted in the slot
on the tensioner arm, turn the tensioner arm
until the timing belt is slack. Tighten the
securing bolt slightly to hold the tensioner in
this position.
Refitting
3To refit the timing belt, first ensure that the
coolant pump is correctly positioned by
checking that the lug on the coolant pump
flange is aligned with the corresponding lug
on the cylinder block. If this is not the case,
slacken the coolant pump mounting bolts
slightly and move the pump accordingly.
Tighten the bolts to the specified torque on
completion (see Chapter 3).
4Refit the timing belt as described in Section 4,
then tension it as follows.
Adjustment
5Slacken the tensioner pulley securing bolt
and move the tensioner arm anti-clockwise,
until the tensioner pointer lies at its stop.
Tighten the tensioner pulley securing bolt to
hold the tensioner in this position.
6Turn the crankshaft through two complete
revolutions in the normal direction of rotation
and check that with the crankshaft pulley TDC
mark aligned with the pointer on the rear
timing belt cover, the TDC marks on the
camshaft sprockets are still aligned with the
notches in the camshaft cover.
7Slacken the tensioner pulley securing bolt
once again and move the tensioner arm
clockwise, until the tensioner pointer is
aligned with the notch in the tensioner. In the
first few hours of operation a new belt will be
subjected to ‘settling-in’, (known as the
running-in procedure). If you are refitting a
used belt (one that has been ‘run-in’), align the
pointer to approximately 4 mm to the left of
the notch, refer to Section 14 in Chapter 2A.
Tighten the tensioner pulley securing bolt
securely. Turn the crankshaft through onecomplete revolution in the normal direction of
rotation and check that the crankshaft and
camshaft timing marks still align, then refit the
remainder of the components as described in
Section 4.
8With the timing belt adjustment set in this
way, correct tension will always be maintained
by the automatic tensioner and no further
checking or adjustment will be necessary.
6Camshaft front oil seal-
removal and refitting
3
Note: A new timing belt should be used on
refitting
Removal
1The camshaft front oil seals may be
renewed with the engine in the vehicle without
removing the camshafts as follows.
2Remove the timing belt and the relevant
camshaft sprocket(s), as described in Section 4.
3Punch or drill a small hole in the centre of
the now-exposed oil seal. Screw in a
self-tapping screw, and pull on the screw with
pliers to extract the seal.
4Clean the oil seal seat with a wooden or
plastic scraper.
5Turn the camshaft until the locating peg for
the camshaft sprocket is uppermost, then
lubricate the lips of a new camshaft front oil
seal with a little grease, and fit the oil seal,
using a tube or socket of similar diameter with
a washer and the camshaft sprocket bolt.Screw the camshaft sprocket bolt into the end
of the camshaft to draw the oil seal into
position on its shoulder (see illustration).
6Where applicable, repeat the procedure on
the remaining camshaft oil seal.
Refitting
7Refit the camshaft sprockets, the timing
belt and tension the timing belt as described
in Sections 4 and 5.
7Camshafts- removal,
inspection and refitting
4
Note: A new timing belt should be used on
refitting
Removal
1Remove the timing belt and the relevant
camshaft sprockets, as described in Section 4.
2If the exhaust camshaft is to be removed,
unscrew the two securing bolts and remove
the distributor from the end of the cylinder
head, referring to Chapter 5, if necessary.
3Check the camshaft bearing caps for identi-
fication marks, and if none are present, make
corresponding marks on the bearing caps and
the top surface of the cylinder head using a
centre punch. Note the orientation of the
bearing caps before removal, as they must be
refitted in exactly the same positions from
which they are removed (see illustration).
4Loosen the relevant camshaft bearing cap
nuts by half a turn, then loosen all the nuts by
a further half turn and so on (this is necessary
to slowly relieve the tension in the valve
springs). Note that the exhaust camshaft rear
bearing cap that also supports the distributor
is secured by four nuts (see illustration).
5Remove the bearing cap nuts and the
bearing caps, then carefully lift the relevant
camshaft from the cylinder head without
jerking.
6Repeat the procedure for the remaining
camshaft if desired.
Inspection
7With the camshaft(s) removed, examine the
bearing surfaces in the cylinder head and
bearing caps for signs of obvious wear or
2B•6DOHC engine procedures
6.5 Using the camshaft sprocket bolt,
washer, and a tube to fit a new camshaft
front oil seal
7.4 Exhaust camshaft rear bearing cap
securing nuts (arrowed)7.3 Camshaft bearing cap. Note position
of identification mark (arrowed)
32Release the securing clips and remove the
main outer timing belt cover, then unclip the
smaller outer timing belt cover from the
coolant pump.
33Turn the crankshaft through at least
quarter of a turn clockwise using a socket or
spanner on the crankshaft sprocket bolt.
34If the special gauge is available, place the
locked gauge at the centre of the belt run
between the coolant pump and the camshaft
sprocket. The gauge should locate on the
timing belt (see illustration).
35Slowly release the operating lever on the
gauge, then lightly tap the gauge two or three
times, and note the reading on the scale (see
illustration).
36If the reading is not as specified, loosen
the three coolant pump securing bolts, and
rotate the pump in the required direction to
achieve the desired reading on the gauge.
Rotate the pump clockwise to increase the
belt tension, or anti-clockwise to decrease the
tension.
37Lightly tighten the coolant pump securing
bolts.
38Remove the tensioning gauge, and turn
the crankshaft through one full turn clockwise.
39Re-check the belt tension as described in
paragraphs 4 and 5.
40If the tension is not as specified, repeat
paragraphs 6 to 9 inclusive until the desired,
consistent, reading is obtained.
41On completion of adjustment, remove the
checking gauge, tighten the coolant pump
bolts to the specified torque, and refit the
outer timing belt covers.
42If the special checking gauge is not
available, the timing belt tension can be
checked approximately by twisting the belt
between the thumb and forefinger, at the
centre of the run between the coolant pump
and the camshaft sprocket. It should just be
possible to twist the belt through 90°using
moderate pressure (see illustration). If
adjustment is necessary, continue as
described previously in this Section, but have
the belt tension checked by a Vauxhall dealer
using the special gauge at the earliest
opportunity. If in doubt, err on the tight side
when adjusting the tension, as if the belt is too
slack, it may jump on the sprockets, which
could result in serious engine damage.12Timing belt and tensioner 1.4
and 1.6 models (not C16 NZ2) -
removal, refitting and adjustment
3
Removal
1Remove the timing belt outer covers as
described in Section 11, paragraphs 1 to 5.
2To lock the tensioner in its slackest position
for removal and refitting, move the tensioner
indicator arm clockwise until the holes align in
the baseplate and the arm. Then insert a
close-fitting pin, such as a drift, to retain them
(see illustration). The tensioner can then be
unbolted, or the belt can be removed.
3Check that the tensioner roller rotates
smoothly and easily, with no noises or signs
of free play, roughness or notchy movement.
Check also that there is no sign of physical
wear or damage. If the tensioner is faulty in
any way, or if there is any reason to doubt the
continued efficiency of its spring, the
complete assembly must be renewed.
Refitting
4On refitting, ensure that the tensioner
baseplate lug engages with the hole in the oil
pump housing, then tighten the tensioner bolt
securely and remove the locking pin; the
tensioner should be quite free to move.
5Set the belt tension as described below.
Adjustment
6Whenever the timing belt is disturbed,
whether during belt renewal or any otherengine overhaul work, its tension must be set
on assembly - note that this procedure must
only be carried out on a cold engine.
7It is assumed that the belt has been
removed and refitted, i.e. that the crankshaft
pulley and timing belt outer covers are
removed, that the tensioner is unlocked (see
above) and that No 1 cylinder is in its firing
position (just before TDC on the compression
stroke). Temporarily refit the crankshaft pulley
bolt and remove the spark plugs so that the
crankshaft can be rotated easily.
8Note also that turning the coolant pump
with the precision required is a great deal
easier if a special spanner (Kent-Moore Part
No KM-421-A) is used. Alternatives are
available from manufacturers such as
Sykes-Pickavant (Part No 031300) (see
illustration).
9With the belt refitted and correctly routed
(see Section 11), ensure that the punch mark
on the crankshaft sprocket and the stamped
line on the camshaft sprocket are aligned with
their respective timing belt rear cover notches
(see illustrations).
10Tighten the belt by slackening its three
securing bolts, and turning the coolant pump
clockwise until the holes align in the tensioner
indicator arm and baseplate (the tensioner
indicator arm will then have moved fully
clockwise to its stop). Lightly tighten the
pump securing bolts, just sufficiently to
prevent the pump from moving.
11Using a spanner applied to the crankshaft
pulley bolt, turn the crankshaft smoothly
2A•16SOHC engine procedures
11.34 Tension blade KM-510-A correctly
positioned on timing belt. Belt must pass
through points A, B and C - SOHC engines11.42 Checking timing belt tension by
twisting belt through 90º between thumb
and forefinger
12.8 Using a special spanner to adjust the
timing belt by moving the coolant pump12.2 Using a close-fitting drift to lock the
tensioner. Note baseplate lug engaged in
oil pump housing (arrowed)
11.35 Note the reading on the scale of the
tension gauge -
1.6 litre engine
(without jerking it or the belt may jump a
tooth), through 2 complete revolutions (720°)
clockwise, until the camshaft and crankshaft
sprocket timing marks are once again aligned
as described in paragraph 13. The position of
the coolant pump must not alter.
12Slacken the timing belt by turning the
coolant pump anti-clockwise until the
tensioner’s indicator pointer is in the centre of
its baseplate notch; the timing belt tension is
then correct (see illustration). Tighten the
coolant pump bolts to the specified torque
wrench setting (see Chapter 3), then turn the
crankshaft through two further turns
clockwise and recheck the setting.
13If the pointer and notch are not aligned,
the operation must be repeated from
paragraph 7. On completion, refit all
components removed.
13Timing belt cover aperture,
1.4 and 1.6 models - general
General
The rear timing belt cover fitted to 1991 and
1992 model year 1.4 and 1.6 litre engines,
incorporates a small aperture just above the
oil pump housing. In certain circumstances, it
is possible for foreign objects, such as gravel,
to penetrate through this aperture and cause
the timing belt to jump a tooth on its
sprockets. For this reason, it is desirable to
cover the aperture to prevent the possibility of
this occurrence. A modified cover without an
aperture was introduced for 1993 models.
A piece of suitably moulded sponge rubber
(P/N 90469594), is available from Vauxhall
dealers to enable the aperture to be covered.
On models without power steering, the
sponge rubber can be inserted into the cover
aperture from above. If power steering is
fitted, the sponge rubber is inserted into place
from below. If access is difficult, particularly if
the drivebelt is of the ribbed V-belt type, it
may be easier to remove the alternator/power
steering pump drivebelt as described in
Chapter 5. Refit, and where applicable adjust,
the belt tension on completion.
14Timing belt and tensioner C16
NZ2, 1.8 and 2.0 litre - removal,
refitting and adjustment
3
Removal
1An alternative type of spring loaded
automatic timing belt tensioner is fitted to
these engines, from 1993 onward (see
illustration). The tensioner assembly is similar
to other automatic tensioners, but the removal
and refitting procedures vary as follows.
2The timing belt main outer cover may be
secured either by clips or by hexagon-headed
screws to the rear cover; in some cases, a
combination of clips and screws may be used.
3To release the belt tension before removal,
unscrew the timing belt tensioner securing
bolt slightly then, with a tool inserted in the
slot on the tensioner arm, turn the tensioner
arm until the timing belt is slack. If necessary,remove completely and examine the tensioner
as described in Section 12.
Refitting
4Refit the tensioner into position and tighten
the securing bolt slightly.
5Ensure that the coolant pump is correctly
positioned by checking that the lug on the
coolant pump flange is aligned with the
corresponding lug on the cylinder block. If this
is not the case, slacken the coolant pump
mounting bolts slightly and move the pump
accordingly (see Chapter 3). Tighten the bolts
to the specified torque on completion.
6Refit the timing belt then tension it as
follows.
Adjustment
7Slacken the automatic tensioner securing
bolt and move the tensioner arm anti-
clockwise, until the tensioner pointer lies at its
stop. Tighten the tensioner securing bolt to
hold the tensioner in this position.
SOHC engine procedures 2A•17
12.12 Timing belt tension is correct when
the tensioner indicator pointer aligns with
the centre of the baseplate notch12.9B . . . and stamped line (A) on
camshaft sprocket with timing belt rear
cover notch (B)12.9A Align punch mark (A) on crankshaft
sprocket with timing belt rear
cover notch (B) . . .
2A
14.1 Timing belt automatic tensioner details (alternative type)
A Alignment lugs on coolant pump and cylinder block
B Tensioner pointer aligned with notch in tensioner bracket
1 Move the tensioner arm anti-clockwise to release the belt tension
2 Move the tensioner arm clockwise to tension the belt
8Turn the crankshaft through two complete
revolutions in the normal direction of rotation,
and check that with the crankshaft pulley TDC
mark aligned with the pointer on the rear
timing belt cover. The TDC mark on the
camshaft sprocket is still aligned with the
notch in the timing belt rear cover. Slacken
the automatic tensioner securing bolt again
and move the tensioner arm clockwise, until
the tensioner pointer is aligned with the notch
in the tensioner bracket. In the first few hours
of operation a new belt will be subjected to
‘settling-in’, (known as the running-in
procedure). If you are refitting a used belt (one
that has been ‘run-in’), align the pointer to
approximately 4 mm to the left of the notch
(see illustration).
9Tighten the tensioner securing bolt
securely. Turn the crankshaft through one
complete revolution, in the normal direction of
rotation, and check that the crankshaft and
camshaft timing marks still align. Then refit
the remainder of the components as
described in Section 12.
10With the timing belt adjustment set in this
way, correct tension will always be maintained
by the automatic tensioner and no further
checking or adjustment will be necessary.
15Camshaft front oil seal -
removal and refitting
3
Removal
1The camshaft front oil seal may be renewed
with the engine in the vehicle without
removing the camshaft as follows.
2Remove the timing belt and the camshaft
sprocket, as described in Section 11.
3Punch or drill a small hole in the centre of
the now-exposed oil seal. Screw in a
self-tapping screw, and pull on the screw with
pliers to extract the seal.
Refitting
4Clean the oil seal seat with a wooden or
plastic scraper.
5Grease the lips of the new seal, and drive it
into position until it is flush with the housing,
using a socket or tube. Take care not to
damage the seal lips during fitting.
6Refit the camshaft sprocket and the timing
belt and tension the timing belt as described
in Section 11.
16Camshaft rear oil seal -
removal and refitting
3
Removal
1The camshaft rear oil seal may be renewed
with the engine in the vehicle without
removing the camshaft as follows.
2Remove the distributor as described in
Chapter 53On 1.4 and 1.6 litre models (except C16
NZ2), the seal takes the form of an O-ring on
the rear of the distributor body. Prise off the
old O-ring carefully, using a screwdriver.
4On C16 NZ2, 1.8 and 2.0 litre models, prise
the seal from the camshaft housing
Refitting
5 On 1.4 and 1.6 litre models (except C16
NZ2), fit the new O-ring, and refit the
distributor as described in Chapter 5.
6On C16 NZ2, 1.8 and 2.0 litre models, fit the
new seal so that it is flush with the end of the
housing, then refit the distributor components
as described in Chapter 5.
17Camshaft housing and
camshaft -general
Note: The engine must be cold when
removing the camshaft housing. Do not
remove the camshaft housing from a hot
engine. New cylinder head bolts must be used
on refitting and sealer will be required when
refitting the camshaft housing. Also see
paragraph 3 before starting work:
General
1The camshaft can only be removed without
disturbing the housing, if a special tool is
available to depress the cam followers whilst
the camshaft is withdrawn.2If such a tool is available, the camshaft can
be removed, after removing the timing belt
and camshaft sprocket as described in
Section 11.
3If the special tool is not available, the
camshaft housing must be removed. Since
the cylinder head bolts must be removed, it is
strongly recommended that a new cylinder
head gasket is fitted. If the gasket is not
renewed, and it “blows” on reassembly, the
cylinder head will have to be removed to
renew the gasket, and another new set of
bolts will have to be obtained for refitting. You
have been warned!
4Removal and refitting of the camshaft
housing is described in Section 18, along with
cylinder head removal and refitting. If it is
decided not to disturb the cylinder head, the
relevant paragraphs referring specifically to
cylinder head removal and refitting can be
ignored.
5Removal of the camshaft from the housing
is described in Section 18.
18Camshaft housing and
camshaft - dismantling,
inspection and reassembly
4
Dismantling
1With the camshaft housing removed from
the cylinder head as described in Section 18,
continue as follows.
2Remove the distributor and it’s
components as described in Chapter 5 and
on C 16 NZ2, 1.8 and 2.0 litre, carefully prise
out the camshaft rear oil seal.
3On carburettor models, remove the fuel
pump, referring to Chapter 4A, if necessary.
4Working at the distributor end of the
camshaft, unscrew the two camshaft
thrustplate securing bolts, using an Allen key
or hexagon bit (see illustration).
5Withdraw the thrustplate, noting which way
round it is fitted (see illustration).
6Carefully withdraw the camshaft from the
distributor end of the camshaft housing,
taking care not to damage the bearing
journals (see illustration).
2A•18SOHC engine procedures
14.8 Timing belt adjustment
1 Alignment for new belts
2 Alignment for ‘run-in’ belts (gap is
approximately 4 mm to the left of centre)
18.4 Camshaft thrustplate and
securing bolts -
1.6 litre engine
REF•4General Repair Procedures
Whenever servicing, repair or overhaul work
is carried out on the car or its components, it is
necessary to observe the following procedures
and instructions. This will assist in carrying out
the operation efficiently and to a professional
standard of workmanship.
Joint mating faces and gaskets
When separating components at their
mating faces, never insert screwdrivers or
similar implements into the joint between the
faces in order to prise them apart. This can
cause severe damage which results in oil
leaks, coolant leaks, etc upon reassembly.
Separation is usually achieved by tapping
along the joint with a soft-faced hammer in
order to break the seal. However, note that this
method may not be suitable where dowels are
used for component location.
Where a gasket is used between the mating
faces of two components, ensure that it is
renewed on reassembly, and fit it dry unless
otherwise stated in the repair procedure. Make
sure that the mating faces are clean and dry,
with all traces of old gasket removed. When
cleaning a joint face, use a tool which is not
likely to score or damage the face, and remove
any burrs or nicks with an oilstone or fine file.
Make sure that tapped holes are cleaned
with a pipe cleaner, and keep them free of
jointing compound, if this is being used, unless
specifically instructed otherwise.
Ensure that all orifices, channels or pipes
are clear, and blow through them, preferably
using compressed air.
Oil seals
Oil seals can be removed by levering them
out with a wide flat-bladed screwdriver or
similar implement. Alternatively, a number of
self-tapping screws may be screwed into the
seal, and these used as a purchase for pliers
or some similar device in order to pull the seal
free.
Whenever an oil seal is removed from its
working location, either individually or as part
of an assembly, it should be renewed.
The very fine sealing lip of the seal is easily
damaged, and will not seal if the surface it
contacts is not completely clean and free from
scratches, nicks or grooves.
Protect the lips of the seal from any surface
which may damage them in the course of
fitting. Use tape or a conical sleeve where
possible. Lubricate the seal lips with oil before
fitting and, on dual-lipped seals, fill the space
between the lips with grease.
Unless otherwise stated, oil seals must be
fitted with their sealing lips toward the
lubricant to be sealed.
Use a tubular drift or block of wood of the
appropriate size to install the seal and, if the
seal housing is shouldered, drive the seal
down to the shoulder. If the seal housing is
unshouldered, the seal should be fitted with its
face flush with the housing top face (unless
otherwise instructed).
Screw threads and fastenings
Seized nuts, bolts and screws are quite a
common occurrence where corrosion has set
in, and the use of penetrating oil or releasing
fluid will often overcome this problem if the
offending item is soaked for a while before
attempting to release it. The use of an impact
driver may also provide a means of releasing
such stubborn fastening devices, when used
in conjunction with the appropriate
screwdriver bit or socket. If none of these
methods works, it may be necessary to resort
to the careful application of heat, or the use of
a hacksaw or nut splitter device.
Studs are usually removed by locking two
nuts together on the threaded part, and then
using a spanner on the lower nut to unscrew
the stud. Studs or bolts which have broken off
below the surface of the component in which
they are mounted can sometimes be removed
using a proprietary stud extractor. Always
ensure that a blind tapped hole is completely
free from oil, grease, water or other fluid
before installing the bolt or stud. Failure to do
this could cause the housing to crack due to
the hydraulic action of the bolt or stud as it is
screwed in.
When tightening a castellated nut to accept
a split pin, tighten the nut to the specified
torque, where applicable, and then tighten
further to the next split pin hole. Never slacken
the nut to align the split pin hole, unless stated
in the repair procedure.
When checking or retightening a nut or bolt
to a specified torque setting, slacken the nut
or bolt by a quarter of a turn, and then
retighten to the specified setting. However,
this should not be attempted where angular
tightening has been used.
For some screw fastenings, notably cylinder
head bolts or nuts, torque wrench settings are
no longer specified for the latter stages of
tightening, “angle-tightening” being called up
instead. Typically, a fairly low torque wrench
setting will be applied to the bolts/nuts in
the correct sequence, followed by one or
more stages of tightening through specified
angles.
Locknuts, locktabs and washers
Any fastening which will rotate against a
component or housing in the course of
tightening should always have a washer
between it and the relevant component or
housing.
Spring or split washers should always be
renewed when they are used to lock a critical
component such as a big-end bearing
retaining bolt or nut. Locktabs which are
folded over to retain a nut or bolt should
always be renewed.
Self-locking nuts can be re-used in non-
critical areas, providing resistance can be felt
when the locking portion passes over the bolt
or stud thread. However, it should be noted
that self-locking stiffnuts tend to lose theireffectiveness after long periods of use, and in
such cases should be renewed as a matter of
course.
Split pins must always be replaced with new
ones of the correct size for the hole.
When thread-locking compound is found on
the threads of a fastener which is to be re-
used, it should be cleaned off with a wire
brush and solvent, and fresh compound
applied on reassembly.
Special tools
Some repair procedures in this manual
entail the use of special tools such as a press,
two or three-legged pullers, spring
compressors, etc. Wherever possible, suitable
readily-available alternatives to the
manufacturer’s special tools are described,
and are shown in use. Unless you are highly-
skilled and have a thorough understanding of
the procedures described, never attempt to
bypass the use of any special tool when the
procedure described specifies its use. Not
only is there a very great risk of personal injury,
but expensive damage could be caused to the
components involved.
Environmental considerations
When disposing of used engine oil, brake
fluid, antifreeze, etc, give due consideration to
any detrimental environmental effects. Do not,
for instance, pour any of the above liquids
down drains into the general sewage system,
or onto the ground to soak away. Many local
council refuse tips provide a facility for waste
oil disposal, as do some garages. If none of
these facilities are available, consult your local
Environmental Health Department for further
advice.
With the universal tightening-up of
legislation regarding the emission of
environmentally-harmful substances from
motor vehicles, most current vehicles have
tamperproof devices fitted to the main
adjustment points of the fuel system. These
devices are primarily designed to prevent
unqualified persons from adjusting the fuel/air
mixture, with the chance of a consequent
increase in toxic emissions. If such devices are
encountered during servicing or overhaul, they
should, wherever possible, be renewed or
refitted in accordance with the vehicle
manufacturer’s requirements or current
legislation.
Note: It is
antisocial and
illegal to dump
oil down the
drain. To find
the location of
your local oil
recycling
bank, call this
number free.
MOTTest Checks REF•11
MExamine the handbrake mechanism,
checking for frayed or broken cables,
excessive corrosion, or wear or insecurity of
the linkage. Check that the mechanism works
on each relevant wheel, and releases fully,
without binding.
MIt is not possible to test brake efficiency
without special equipment, but a road test can
be carried out later to check that the vehicle
pulls up in a straight line.
Fuel and exhaust systems
MInspect the fuel tank (including the filler
cap), fuel pipes, hoses and unions. All
components must be secure and free from
leaks.
MExamine the exhaust system over its entire
length, checking for any damaged, broken or
missing mountings, security of the retaining
clamps and rust or corrosion.
Wheels and tyres
MExamine the sidewalls and tread area of
each tyre in turn. Check for cuts, tears, lumps,
bulges, separation of the tread, and exposure
of the ply or cord due to wear or damage.
Check that the tyre bead is correctly seated
on the wheel rim, that the valve is sound andproperly seated, and that the wheel is not
distorted or damaged.
MCheck that the tyres are of the correct size
for the vehicle, that they are of the same size
and type on each axle, and that the pressures
are correct.
MCheck the tyre tread depth. The legal
minimum at the time of writing is 1.6 mm over
at least three-quarters of the tread width.
Abnormal tread wear may indicate incorrect
front wheel alignment.
Body corrosion
MCheck the condition of the entire vehicle
structure for signs of corrosion in load-bearing
areas. (These include chassis box sections,
side sills, cross-members, pillars, and all
suspension, steering, braking system and
seat belt mountings and anchorages.) Any
corrosion which has seriously reduced the
thickness of a load-bearing area is likely to
cause the vehicle to fail. In this case
professional repairs are likely to be needed.
MDamage or corrosion which causes sharp
or otherwise dangerous edges to be exposed
will also cause the vehicle to fail.
Petrol models
MHave the engine at normal operating
temperature, and make sure that it is in good
tune (ignition system in good order, air filter
element clean, etc).
MBefore any measurements are carried out,
raise the engine speed to around 2500 rpm,
and hold it at this speed for 20 seconds. Allowthe engine speed to return to idle, and watch
for smoke emissions from the exhaust
tailpipe. If the idle speed is obviously much
too high, or if dense blue or clearly-visible
black smoke comes from the tailpipe for more
than 5 seconds, the vehicle will fail. As a rule
of thumb, blue smoke signifies oil being burnt
(engine wear) while black smoke signifies
unburnt fuel (dirty air cleaner element, or other
carburettor or fuel system fault).
MAn exhaust gas analyser capable of
measuring carbon monoxide (CO) and
hydrocarbons (HC) is now needed. If such an
instrument cannot be hired or borrowed, a
local garage may agree to perform the check
for a small fee.
CO emissions (mixture)
MAt the time of writing, the maximum CO
level at idle is 3.5% for vehicles first used after
August 1986 and 4.5% for older vehicles.
From January 1996 a much tighter limit
(around 0.5%) applies to catalyst-equipped
vehicles first used from August 1992. If the
CO level cannot be reduced far enough to
pass the test (and the fuel and ignition
systems are otherwise in good condition) then
the carburettor is badly worn, or there is some
problem in the fuel injection system or
catalytic converter (as applicable).
HC emissionsMWith the CO emissions within limits, HC
emissions must be no more than 1200 ppm
(parts per million). If the vehicle fails this test
at idle, it can be re-tested at around 2000 rpm;
if the HC level is then 1200 ppm or less, this
counts as a pass.
MExcessive HC emissions can be caused by
oil being burnt, but they are more likely to be
due to unburnt fuel.
Diesel models
MThe only emission test applicable to Diesel
engines is the measuring of exhaust smoke
density. The test involves accelerating the
engine several times to its maximum
unloaded speed.
Note: It is of the utmost importance that the
engine timing belt is in good condition before
the test is carried out.
M
Excessive smoke can be caused by a dirty
air cleaner element. Otherwise, professional
advice may be needed to find the cause.
4Checks carried out on
YOUR VEHICLE’S EXHAUST
EMISSION SYSTEM
REF
Note:Due to the complexity of the automatic transmission, it is difficult
for the home mechanic to properly diagnose and service this unit. For
problems other than the following, the vehicle should be taken to a
dealer service department or automatic transmission specialist. Do not
be too hasty in removing the transmission if a fault is suspected, as
most of the testing is carried out with the unit still fitted.
Fluid leakage
MAutomatic transmission fluid is usually dark in colour. Fluid leaks
should not be confused with engine oil, which can easily be blown
onto the transmission by airflow.
MTo determine the source of a leak, first remove all built-up dirt and
grime from the transmission housing and surrounding areas using
a degreasing agent, or by steam-cleaning. Drive the vehicle at low
speed, so airflow will not blow the leak far from its source. Raise
and support the vehicle, and determine where the leak is coming
from. The following are common areas of leakage:
a)Fluid pan or “sump” (Chapter 1 and 7B).
b)Dipstick tube (Chapter 1 and 7B).
c)Transmission-to-fluid cooler pipes/unions (Chapter 7B).
Transmission fluid brown, or has burned smell
MTransmission fluid level low, or fluid in need of renewal (Chapter 1).
General gear selection problems
MChapter 7B deals with checking and adjusting the selector cable
on automatic transmissions. The following are common problems
that may be caused by a poorly adjusted cable:a)Engine starting in gears other than Park or Neutral.
b)Indicator panel indicating a gear other than the one actually being
used.
c)Vehicle moves when in Park or Neutral.
d)Poor gear shift quality or erratic gear changes.
MRefer to Chapter 7B for the selector cable adjustment procedure.
Transmission will not downshift (kickdown) with
accelerator pedal fully depressed
MLow transmission fluid level (Chapter 1).
MIncorrect selector cable adjustment (Chapter 7B).
Engine will not start in any gear, or starts in gears
other than Park or Neutral
MIncorrect starter/inhibitor switch adjustment (Chapter 7B).
MIncorrect selector cable adjustment (Chapter 7B).
Transmission slips, shifts roughly, is noisy, or has
no drive in forward or reverse gears
MThere are many probable causes for the above problems, but the
home mechanic should be concerned with only one possibility -
fluid level. Before taking the vehicle to a dealer or transmission
specialist, check the fluid level and condition of the fluid as
described in Chapter 1. Correct the fluid level as necessary, or
change the fluid and filter if needed. If the problem persists,
professional help will be necessary.
Clicking or knocking noise on turns (at slow speed
on full-lock)
MLack of constant velocity joint lubricant, possibly due to damaged
gaiter (Chapter 8).
MWorn outer constant velocity joint (Chapter 8).
Vibration when accelerating or decelerating
MWorn inner constant velocity joint (Chapter 8).
MBent or distorted driveshaft (Chapter 8).
REF•16Fault Finding
Automatic transmission
Driveshafts
Noisy in neutral with engine running
MInput shaft bearings worn (noise apparent with clutch pedal
released, but not when depressed), (Chapter 7A).*
MClutch release bearing worn (noise apparent with clutch pedal
depressed, possibly less when released), (Chapter 6).
Noisy in one particular gear
MWorn, damaged or chipped gear teeth (Chapter 7A).*
Difficulty engaging gears
MClutch fault (Chapter 6).
MWorn or damaged gear linkage (Chapter 7A).
MIncorrectly adjusted gear linkage (Chapter 7A).
MWorn synchroniser units (Chapter 7A).*
Jumps out of gear
MWorn or damaged gear linkage (Chapter 7A).
MIncorrectly adjusted gear linkage (Chapter 7A).MWorn synchroniser units (Chapter 7A).*
MWorn selector forks (Chapter 7A).*
Vibration
MLack of oil (Chapter 1).
MWorn bearings (Chapter 7A).*
Lubricant leaks
MLeaking differential output oil seal (Chapter 7A).
MLeaking housing joint (Chapter 7A).*
MLeaking input shaft oil seal (Chapter 7A).*
* Although the corrective action necessary to remedy the symptoms
described is beyond the scope of the home mechanic, the above
information should be helpful in isolating the cause of the condition.
This should enable the owner can communicate clearly with a
professional mechanic.
Manual transmission