check engine OPEL VECTRA 1988 Service Manual Online

14Working under the vehicle, unscrew and
remove the two nuts securing the
engine/transmission rear mounting to the front
subframe, and the three bolts securing the
mounting bracket to the transmission, then
withdraw the mounting bracket (see
illustrations).
15Carefully swing the engine/transmission
assembly across the engine compartment as
necessary, to allow the assembly to be lifted
vertically from the vehicle by raising the hoist.
Take care not to damage any of the
surrounding components in the engine
compartment.
Separation
16With the engine/transmission assembly
removed, support the assembly on blocks of
wood positioned on a workbench, or failing
that, on a clean area of the workshop floor.
17Clean away any external dirt using
paraffin or a water-soluble solvent and a stiff
brush.
18Unbolt and remove the transmission
bellhousing cover plate.
19Ensure that both engine and transmission
are adequately supported, then unscrew and
remove the engine-to-transmission bolts.
20Carefully withdraw the transmission from
the engine, ensuring that the weight of the
transmission is not allowed to hang on the
input shaft while it is engaged with the clutch
friction disc. Note that the transmission
locates on dowels positioned in the cylinder
block.
21On automatic models unbolt the
transmission bellhousing cover plate (three
bolts), then use chalk or a felt-tip pen to mark
the relationship of the torque converter to the
flexplate before unbolting the torque
converter. Note:If the torque converter is
removed (even partially) from the transmission,
a considerable amount of the fluid inside it will
leak out. To prevent this, when prising the
transmission off its locating dowels and
removing it, be careful to keep the torque
converter pressed firmly into the transmission.
If the transmission is to be removed for some
time, retain the torque converter by bolting a
strip of metal across the bellhousing mating
surface. Applying a spanner to the crankshaft
pulley/sprocket bolt, rotate the crankshaft
until the first bolt appears, then use ascrewdriver or similar to jam the flexplate ring
gear teeth to prevent it from rotating as the
bolt is unscrewed. Unscrew each of the three
bolts in turn and remove them.
Reconnection
22Before beginning the refitting operations,
check that the two original bolts that secured
the left-hand transmission rubber mounting to
the vehicle body rotate freely in their threaded
bores in the body. If necessary, re-cut the
threaded bores using an M10 x 1.25 mm tap.
23Where applicable, if the clutch assembly
has been removed from the flywheel, it will
prove easier to refit after the transmission has
been refitted.
24On automatics, if any fluid was spilled from
the torque converter, be careful to refill it as
much as possible. Wipe clean the converter’s
spigot to prevent damage to the transmission’s
input shaft oil seal as the converter is installed,
and ensure that the converter engages
correctly on the fluid pump shaft.
25If the transmission has been renewed, be
careful to flush clean the radiator fluid cooler
passages. Vauxhall recommend the use of
low-pressure compressed air, but this will
require great care to avoid deforming the
radiator.
26Be very careful to ensure that all
components are scrupulously clean, to avoid
the risk of dirt getting into the system.
27Use an M10 x 1.25 bottoming tap to clean
the threads in the torque converters threaded
bosses and ensure that new bolts are
available for reassembly, where applicable.
28Tighten all nuts and bolts to their specified
torque wrench settings.
29Refer also to Section 7, paragraphs 35
and 36.
30Carefully offer the transmission to the
engine until the bellhousing is located on the
dowels in the cylinder block, then refit the
engine-to-transmission bolts, and tighten
them to the specified torque.
31Refit the transmission bellhousing cover
plate.
Refitting
32Working under the vehicle, refit the rear
engine/transmission mounting to the
transmission, using new locking plates under
the bolt heads, and tighten the bolts to the
specified torque.
33Fit the two bolts securing the engine/
transmission rear mounting to the front
subframe, but do not fully tighten at this stage.
34Fit the right-hand engine mounting
bracket to the cylinder block, and tighten the
securing bolts to the specified torque.
35Fit new right-hand engine
mounting-to-body bolts, but do not fully
tighten them at this stage.
36Fit the left-hand transmission mounting
bracket to the transmission, and tighten the
securing bolts to the specified torque.
37Fit new left-hand transmission
mounting-to-body bolts, and tighten them to
the specified torque.
38Tighten the right-hand engine mounting-
to-body bolts and the engine/transmission
rear mounting-to-front subframe bolts to their
specified torques, then remove the lifting
tackle and hoist from the engine.
39Where applicable, the clutch can now be
fitted, and the transmission input shaft can be
pressed into engagement with the splined hub
of the clutch friction disc, (see Chapter 5).
40Reconnect the inboard ends of the
driveshafts to the differential, with reference
to the relevant paragraphs of Chapter 8, and
using new snap rings.
41Refit the front section of the exhaust
system, as described in Chapter 4C.
42Refit the crankshaft pulley, using a
reversal of the removal procedure described
in Section 7, paragraph 22, and tighten the
securing bolt(s) to the specified torque.
43On automatic models, connect the wires
to the various switches, solenoids and
sensors. Replace the transmission breather
hose and oxygen sensor (if fitted).
44Reconnect the transmission earth strap,
and tighten the securing nut.
45Lower the vehicle to the ground.
46Reconnect the speedometer cable to the
transmission, and tighten the securing sleeve.
47Reconnect the reversing lamp wiring.
48On manual transmission models, refit the
clutch cable to the bracket on the
transmission casing, then reconnect the cable
to the release lever, and adjust the cable as
described in Chapter 6. Ensure that the cable
is routed as noted during removal.
49Refit the gear selector linkage, as
described in Chapter 7A, if applicable.
50Proceed as described in Section 7,
paragraphs 41 to 52 inclusive.
51Top-up the transmission oil level, as
described in Chapters 7A and 7B.
52Adjust the selector cable on completion,
and refill the transmission with fluid (see
above).
53Reconnect the battery negative lead.
54Refer to Section 37
SOHC engine procedures 2A•11
8.14B Rear engine/transmission mounting-
to-transmission bolts (arrowed)8.14A Rear engine/transmission
mounting-to-front subframe nuts
2A
If a tap is not available, cut
two slots into the threads of
one of the old flywheel bolts
and use the bolt to remove
the locking compound from the threads.

9Engine and transmission
mountings - renewal
3
Note: New left and right-hand
engine/transmission mounting-to-body bolts
must be used on refitting
1The engine/transmission assembly is
suspended in the engine compartment on
three mountings, two of which are attached to
the transmission, and one to the engine.
Right-hand mounting
2If not already done, apply the handbrake,
then raise the front of the vehicle, and support
securely on axle stands (see “Jacking and
Vehicle Support”)..
3Attach lifting tackle and a hoist to the
engine lifting brackets on the cylinder head,
and support the weight of the engine.
4Working under the vehicle, unbolt the
engine mounting bracket from the cylinder
block, and unbolt the mounting block from the
body, then withdraw the bracket/mounting
assembly (see illustration).
5Unbolt the mounting block from the
bracket.
6Fit the new mounting block to the bracket,
and tighten the securing bolts to the specified
torque.
7Refit the mounting bracket to the cylinder
block, and tighten the securing bolts to the
specified torque.
8Fit new mounting block-to-body bolts, and
tighten them to the specified torque.
9Disconnect the lifting tackle and hoist from
the engine.
10Lower the vehicle to the ground.
Left-hand mounting
11Proceed as described in paragraphs 2
and 3.
12Working under the vehicle, unbolt the
mounting block from the mounting bracket
and the body (see illustration).13Before fitting the new mounting block,
check that the original engine bolts which
secured the mounting block to the body
rotate freely in their threaded bores in the
body. If necessary, re-cut the threaded bores
using an M10 x 1.25 mm tap.
14Fit the new mounting block to the bracket,
and tighten the securing bolts to the specified
torque.
15Fit new mounting block-to-body bolts,
and tighten them to the specified torque.
16Proceed as described in paragraphs 9
and 10.
Rear mounting
17Proceed as described in paragraphs 2
and 3.
18Working under the vehicle, unbolt the
mounting block from the front subframe and
the mounting bracket.
19Fit the new mounting block to the
subframe and mounting bracket, and tighten
the securing bolts to the specified torque.
20Proceed as described in paragraphs 9
and 10.
10Engine dismantling and
reassembly - general
4
General
1Ideally, the engine should be mounted on a
dismantling stand, but if this is not available,
stand the engine on a strong bench, at a
comfortable working height. Failing this, the
engine will have to be stripped down on the
floor.
2Cleanliness is most important, and if theengine is dirty, it should be cleaned with
paraffin in an upright position.
3Avoid working with the engine directly on a
concrete floor, as grit presents a real source
of trouble.
4If the engine oil appears extremely dirty or
contaminated, avoid inverting the engine until
the sump has been removed. This will prevent
any contaminated “sludge” from entering the
oilways.
5As parts are removed, clean them in a
paraffin bath. Do not immerse parts with
internal oilways in paraffin, as it is difficult to
remove, usually requiring a high pressure
hose. Clean oilways with nylon pipe cleaners.
6It is advisable to have containers available
to hold small items, to prevent loss and
confusion when refitting.
7Always obtain complete sets of gaskets
when the engine is being dismantled. Keep
the old gaskets as they can be used as
patterns to make replacements should new
gaskets not be available.
8Where possible, refit nuts, bolts and
washers to their locations after removal of the
relevant components, as this helps protect
the threads, and will also prove helpful during
reassembly.
9Retain unserviceable components, to
compare them with the new components
supplied.
10Many of the engine components are
secured using socket-headed “Torx” or
“Allen” bolts, and tools will be required to
remove and refit such bolts.
11Read through each relevant Section of
this Chapter carefullybeforebeginning work,
to ensure that any special tools that may be
required are available. Many components
(gaskets, oil seals, and certain bolts) must be
renewed on reassembly; where applicable,
obtain the required new components before
starting work.
12Before beginning a complete strip of the
engine, the following ancillary components
can be removed once the engine has been
removed from the vehicle:
2A•12SOHC engine procedures
9.4 Right-hand engine mounting
1 Mounting block-to-body bolts
2 Mounting bracket-to-cylinder block bolts9.12 Left-hand engine/transmission mounting
1 Mounting block-to-body bolts
2 Mounting block-to-mounting bracket bolts
If a tap is not available, cut
two slots into the threads of
one of the old flywheel bolts
and use the bolt to remove
the locking compound from the threads.

21On 1.4 and 1.6 litre engines (except C 16
NZ2), refit the Woodruff key to the end of the
crankshaft where applicable. Then refit the
crankshaft sprocket with the flange and
locating lug for the crankshaft pulley
outermost (see illustration).
22Refit the camshaft sprocket, ensuring that
the locating pin on the end of the camshaft
engages with the hole in the sprocket, and
tighten the securing bolt to the specified
torque. Prevent the camshaft from turning as
during removal. Check the condition of the
camshaft cover gasket and renew if
necessary, then refit the camshaft cover,
ensuring that the HT lead brackets and any
other wiring bracket are correctly located, and
reconnect the breather hose(s) (see
illustrations).
23Temporarily refit the crankshaft pulley and
ensure that the crankshaft pulley andcamshaft sprocket timing marks are still
aligned as described in paragraph 7, then refit
the timing belt around the sprockets (see
illustration), starting at the crankshaft
sprocket.
24Refit the crankshaft pulley, and tighten the
securing bolt(s) to the specified torque (see
illustrations). If necessary, prevent the
crankshaft from turning as during removal.
25Adjust the timing belt tension, as
described in Section 11.
26On 1.6 litre models with power steering,
refit the power steering pump, as described in
Chapter 10.
27Refit the outer timing belt covers, and on
C 16 NZ2, 1.8 and 2.0 litre models, reconnect
the temperature gauge sender wiring.
28Refit the alternator drivebelt and adjust
the drivebelt tension, as described in Chapter
5.29On C 16 NZ2, 1.8 and 2.0 litre models
with power steering, refit the power steering
pump drivebelt and adjust the drivebelt
tension, as described in Chapters 1 and 10.
30Reconnect the battery negative lead.
Adjustment
Note: The manufacturers specify the use of a
special gauge Vauxhall tool No KM-510-A for
checking the timing belt tension. If access to a
gauge cannot be obtained it is strongly
recommended that the vehicle is taken to a
Vauxhall dealer to have the belt tension
checked at the earliest opportunity
31The tension of a used timing belt should
be checked with the engine at normal
operating temperature. The tension of a new
timing belt should be checked with the engine
cold.
SOHC engine procedures 2A•15
11.22A Refit the camshaft sprocket . . .
11.24B Tightening a crankshaft pulley
securing bolt - 2.0 litre engine11.24A Refitting the crankshaft pulley -
1.6 litre engine11.23 Refitting the timing belt -
2.0 litre engine
11.22D . . . fit the cover and tighten the
bolts. Note position of HT lead brackets11.22C Fit the camshaft cover gasket . . .11.22B . . . and tighten the securing bolt to
the specified torque - 2.0 litre engine
11.21 Crankshaft sprocket fits with flange
and pulley locating lug outermost -
1.6 litre engine11.20F . . .then through the specified angle
- 2.0 litre engine
2A

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

Inspection
7With the camshaft removed, examine the
bearings in the camshaft housing for signs of
obvious wear or pitting. If evident, a new
camshaft housing will probably be required.
8The camshaft itself should show no marks
or scoring on the journal or cam lobe
surfaces. If evident, renew the camshaft. Note
that if the camshaft is renewed, all the rocker
arms should also be renewed.
9Check the camshaft thrustplate for signs of
wear or grooves, and renew if evident.
10It is advisable to renew the camshaft front
oil seal as a matter of course if the camshaft
has been removed. Prise out the old seal
using a screwdriver (see illustration).
Reassembly
11Carefully drive in the new front seal until it
is flush with the housing, using a socket or
tube. On C 16 NZ2, 1.8 and 2.0 litre models,
fit a new camshaft rear oil seal. Replace the
distributor O-ring on other models (see
illustrations).
12Begin reassembly by liberally oiling the
bearings in the housing and the oil seal lip.
Carefully insert the camshaft into the housing
from the distributor end, taking care to avoid
damage to the bearings.
13Refit the thrustplate, and tighten the
securing bolts (see illustration). Check the
camshaft endfloat by inserting a feeler blade
between the thrustplate and the camshaft end
flange. If the endfloat exceeds that specified,
renew the thrustplate.14Where applicable, refit the fuel pump,
referring to Chapter 4, if necessary.
15Refit the distributor as described in
Chapter 5.
16Refit the camshaft housing, as described
in Section 18.
17If a new camshaft has been fitted, it is
important to observe the following running-in
schedule (unless otherwise specified by the
manufacturer) immediately after initially
starting the engine:
One minute at 2000 rpm
One minute at 1500 rpm
One minute at 3000 rpm
One minute at 2000 rpm
18Change the engine oil (but not the filter,
unless due) approximately 600 miles (1000
km) after fitting a new camshaft.19Camshafts, “undersize” C16
NZ2, 1.8 and 2.0 litre engines
- general
General
1The camshafts and camshaft housings for
these engines are sorted on production into
one of two size groups; standard and 0.10
mm “undersize”. Note that this is not intended
to provide replacements for worn engines, but
is to allow for production tolerances; either
may be fitted to new engines.
2“Undersize” components are marked with a
spot of violet-coloured paint, that on the
camshaft housing being applied on top at the
timing belt end.3Whenever the camshaft or its housing are
to be renewed, check (by direct
measurement, if necessary) whether they are
standard or undersize and ensure that only
matching items are obtained for reassembly.
20Cylinder head - removal and
refitting (engine in vehicle)
4
Note: The engine must be cold when the
cylinder head is removed. Do not remove the
cylinder head from a hot engine. New cylinder
head bolts and a new cylinder head gasket
must be used on refitting and sealer will be
required when refitting the camshaft housing.
The torque settings stated are only applicable
to latest specification head bolts, available
from Vauxhall. Earlier type or alternative make,
head bolts may require different torques.
Consult your supplier.
Removal
1Disconnect the battery negative lead.
2Drain the cooling system, as described in
Chapter 3.
3Disconnect the exhaust downpipe from the
manifold, referring to Chapter 4C.
4The cylinder head can be removed
complete with the manifolds, or the manifolds
can be detached from the cylinder head
before removal, with reference to the relevant
Sections of Chapter 4A, 4B or 4C. If no work
is to be carried out on the inlet manifold, it can
be unbolted from the cylinder head and
SOHC engine procedures 2A•19
18.10 Prising out the camshaft front oil
seal - 2.0 litre engine
18.13 Tightening a camshaft thrustplate
securing bolt - 2.0 litre engine18.11B Fitting a new camshaft rear oil seal
- 2.0 litre engine18.11A Fitting a new camshaft front oil
seal using a special tool - 2.0 litre engine
18.6 Withdrawing the camshaft from the
housing - 2.0 litre engine18.5 Removing the camshaft thrustplate -
2.0 litre engine
2A

supported to one side out of the way, thus
avoiding the need to disconnect the relevant
hoses, pipes and wiring.
5If the cylinder head is to be removed
complete with the manifolds, disconnect all
relevant hoses, pipes and wiring from the inlet
manifold and associated components,
referring to Chapter 4A or 4B. On carburettor
models, disconnect the hot air hose from the
shroud on the exhaust manifold. Loosen the
alternator mountings, with reference to
Chapter 5, then unbolt the upper alternator
mounting from the inlet manifold.
6If the inlet manifold is to be left in the engine
compartment, continue as follows, otherwise
go on to paragraph 15.
7Disconnect the air cleaner trunking from the
air box on the carburettor or throttle body, or
directly from the throttle body (as applicable),
and disconnect the camshaft cover breather
hose that runs to the carburettor or throttle
body (as applicable), (see illustration).
8On C 16 NZ2, 1.8 and 2.0 litre models,
disconnect the smaller coolant hose from the
top of the thermostat housing.
9On 1.6 litre models (except C 16 NZ2),
disconnect the breather hose (which runs
from the camshaft cover to the inlet manifold)
at the camshaft cover.
10On fuel injection models, unbolt the two
wiring harnesses earth leads from the
camshaft housing (see illustration).
11On 1.4 and 1.6 litre models (except C 16
NZ2), disconnect the stub hose that connects
the crankcase breather tube to the rear of thecamshaft housing (see illustration).
12Loosen the alternator mountings, referring
to Chapter 5, then unbolt the upper alternator
mounting from the inlet manifold.
13Make a final check to ensure that all
necessary hoses, pipes and wires have been
disconnected, then unscrew the securing
nuts, noting the location of the engine lifting
bracket, and lift the inlet manifold from the
cylinder head. Ensure that the manifold is
properly supported, taking care not to strain
any of the hoses, pipes and wires, etc., which
are still connected.
14Recover the manifold gasket from the
cylinder head.
15If desired, remove the exhaust manifold,
with reference to Chapter 4C.
16Remove the timing belt and the camshaft
sprocket, as described in Section 11.
17Unscrew the two upper rear timing belt
cover securing bolts from the camshaft
housing.
18Disconnect the HT leads from the spark
plugs and the coil, labelling them if necessary
to aid refitting, and remove the distributor
cap, referring to Chapter 5. Where applicable,
disconnect the distributor wiring plug.
19If not already done, disconnect the stub
hose that connects the crankcase breather
tube to the camshaft housing. If applicable
unscrew the bolt securing the crankcase
breather tube bracket to the end of the
cylinder head (see illustrations).
20Disconnect the coolant hoses from the
thermostat housing.21On carburettor models, disconnect the fuel
hoses from the fuel pump. Be prepared for fuel
spillage, and plug the open ends of the hoses,
to prevent further fuel loss and dirt ingress.
22Make a final check to ensure that all
relevant hoses, pipes and wires, etc., have
been disconnected.
23Working from the outside inwards in a
spiral pattern as shown (see illustration),
loosen all the cylinder head bolts by a quarter
of a turn. Then loosen all the bolts by half a
turn, and finally loosen and remove the bolts.
Recover the washers.
24Lift the camshaft housing from the
cylinder head (see illustration). If necessary,
tap the housing gently with a soft-faced mallet
to free it from the cylinder head, but do not
lever at the mating faces. Note that the
camshaft housing is located on dowels.
25Lift the rocker arms and their thrust pads
from the cylinder head, keeping them in order
so that they can be refitted in their original
positions (see illustrations).
26Lift the hydraulic valve lifters from the
cylinder head, and place them upright in an oil
bath until they are to be refitted (see
illustration). Ensure that the depth of oil is
sufficient to fully cover the valve lifters, and
keep the lifters in order, so that they can be
refitted in their original positions.
27Lift the cylinder head from the cylinder
block (see illustration). If necessary, tap the
cylinder head gently with a soft-faced mallet
to free it from the block, but do not lever at the
mating faces. Note that the cylinder head is
located on dowels.
2A•20SOHC engine procedures
20.7 Disconnecting a camshaft cover
breather hose -
2.0 litre engine20.11 Disconnecting the crankcase
breather tube stub hose -
1.6 litre engine
20.23 Cylinder head bolt loosening
sequence - SOHC engines20.19B Unbolting the crankcase breather
tube bracket from the cylinder head -
2.0 litre model20.19A Disconnecting the crankcase
breather tube stub hose -
2.0 litre engine
20.10 Unbolting the fuel injection wiring
harness earth leads from the camshaft
housing - 2.0 litre engine

40Refit the camshaft sprocket and the
timing belt and tension the timing belt as
described in Section 11.
41Where applicable, refit the manifolds to
the cylinder head, with reference to Chapter
4A, 4B or 4C, using new gaskets.
42Reconnect the exhaust downpipe to the
manifold, using a new gasket, referring to
Chapter 4C, if necessary.
43Refit the upper alternator mounting to the
inlet manifold, then adjust the alternator
drivebelt tension, as described in Chapter 5.
44Refill the cooling system, as described in
Chapter 3.
45On completion, check that all relevant
hoses, pipes and wires, etc., have been
reconnected.
46When the engine is started, check for
signs of leaks.
47Once the engine has reached normal
operating temperature, check and if
necessary adjust the idle speed (where
applicable) and the mixture (where
applicable), with reference to Chapter 4A or
4B.
21Cylinder head - removal and
refitting (engine removed)
4
Note: New cylinder head bolts and a new
cylinder head gasket must be used on
refitting, and sealer will be required when
refitting the camshaft housing.
The torque settings stated are only applicable
to latest specification head bolts, available
from Vauxhall. Earlier type or alternative make,
head bolts may require different torques.
Consult your supplier.
Removal
1The cylinder head can be removed
complete with the manifolds, or the manifolds
can be detached from the cylinder head
before removal, with reference Chapter 4A,
4B or 4C.
2Remove the timing belt and the camshaft
sprocket, as described in Section 11.
3Unscrew the two upper rear timing belt
cover securing bolts from the camshaft
housing (see illustration).4Disconnect the HT leads from the spark
plugs, labelling them if necessary to aid
refitting, and remove the distributor cap
referring to Chapter 5.
5If not already done, disconnect the stub
hose that connects the crankcase breather
tube to the camshaft housing. If applicable,
unscrew the bolt securing the crankcase
breather tube bracket to the end of the
cylinder head.
6Make a final check to ensure that all
relevant hoses, pipes and wires have been
disconnected.
Refitting
7Proceed as described in Section 21,
paragraphs 23 to 41 inclusive, but in addition
note the following.
8On completion check that all relevant
hoses, pipes and wires, etc., have been
reconnected.
22Cylinder head -dismantling
and reassembly
4
Note: A valve spring compressor tool will be
required for this operation. New valve stem oil
seals must be used on reassembly
Dismantling
1With the cylinder head removed as
described in Section 21, clean away all
external dirt.
2If not already done, remove the thermostat
housing, and on 1.4 and 1.6 litre models, thethermostat, as described in Chapter 3.
Remove the manifolds as described in
Chapter 4A, 4B or 4C. Remove the spark
plugs if not already done.
3To remove a valve, fit a valve spring
compressor tool. Ensure that the arms of the
compressor tool are securely positioned on
the head of the valve and the spring cap (see
illustration).
4Compress the valve spring to relieve the
pressure of the spring cap acting on the
collets. If the spring cap sticks on the valve
stem, support the compressor tool and give
the end a light tap with a hammer to help free
the spring cap.
5Extract the two split collets, then slowly
release the compressor tool.
6Remove the spring cap, spring, valve stem
oil seal, and the spring seat, then withdraw
the valve.
2A•22SOHC engine procedures
20.36 Fit new cylinder head bolts, ensuring
that the washers are in place20.37B Tighten the cylinder head bolts to
the specified torque . . .
22.3 Valve spring compressor tool fitted to
No 1 exhaust valve - 2.0 litre engine21.3 Upper rear timing belt cover securing
bolts (arrowed) - 1.6 litre engine
20.37C . . .then through the specified
angle - 2.0 litre engine
20.37A Cylinder head bolt tightening
sequence - SOHC engines

23Cylinder head - inspection
and renovation
4
Note: Refer to a dealer for advice before
attempting to carry out valve grinding or valve
seat reciting operations, as these operations
may not be possible for the DIY mechanic.
This is due to the fitment of hardened valve
seats for use with unleaded petrol
Inspection
1Remember that the cylinder head is of light
alloy construction and is easily damaged, use
a blunt scraper or rotary wire brush to clean all
traces of carbon deposits from the
combustion spaces and the ports. The valve
stems and valve guides should also be freed
from any carbon deposits. Wash the
combustion spaces and ports down with
paraffin and scrape the cylinder head surface
free of any foreign matter with the side of a
steel rule, or a similar article.
2If the engine is installed in the car, clean the
pistons and the top of the cylinder bores. If
the pistons are still in the block, it is essential
that great care is taken to ensure that no
carbon gets into the cylinder bores. This could
scratch the cylinder walls or cause damage to
the pistons and rings. To ensure this does not
happen, first turn the crankshaft so that two of
the pistons are at the top of their bores. Insert
rag into the other two bores or seal them off
with paper and masking tape. The waterways
should also be covered with small pieces of
masking tape, to prevent particles of carbon
entering the cooling system and damaging the
coolant pump.
3Press a little grease into the gap between
the cylinder walls and the two pistons that are
to be worked on. With a blunt scraper,
carefully scrape away the carbon from the
piston crown, taking great care not to scratch
the aluminium. Also scrape away the carbon
from the surrounding lip of the cylinder wall.
When all carbon has been removed, scrape
away the grease that will now be
contaminated with carbon particles, taking
care not to press any into the bores. To assist
prevention of carbon build-up, the piston
crown can be polished with a metal polish.
Remove the rags or masking tape from the
other two cylinders, and turn the crankshaft
so that the two pistons that were at thebottom are now at the top. Place rag or
masking tape in the cylinders that have been
decarbonised, and continue as just described.
4Examine the heads of the valves for pitting
and burning, especially the heads of the
exhaust valves. The valve seatings should be
examined at the same time. If the pitting on
the valve and seat is very slight, the marks
can be removed by grinding the seats and
valves together with coarse, and then fine,
valve grinding paste.
5Where bad pitting has occurred to the valve
seats, it will be necessary to recut them and fit
new valves. This latter job should be entrusted
to the local dealer or engineering works. In
practice it is very seldom that the seats are so
badly worn. Normally it is the valve that is too
badly worn for refitting, and the owner can
easily buy a new set of valves and match
them to the seats by valve grinding.
Renovation
6Valve grinding is carried out as follows.
Smear a trace of coarse carborundum paste
on the seat face and apply a suction grinder
tool to the valve head. With a semi-rotary
motion, grind the valve head to its seat, lifting
the valve occasionally to redistribute the
grinding paste. When a dull matt even surface
is produced on both the valve seat and the
valve, wipe off the paste and repeat the
process with fine carborundum paste, lifting
and turning the valve to redistribute the paste
as before. A light spring placed under the
valve head will greatly ease this operation.
When a smooth unbroken ring of light grey
matt finish is produced, on both valve and
valve seat faces, the grinding operation is
complete. Carefully clean away every trace of
grinding compound, taking great care to leave
none in the ports or in the valve guides. Clean
the valves and valve seats with a
paraffin-soaked rag, then with a clean rag,
and finally, if an air line is available, blow the
valves, valve guides and valve ports clean.
7Check that all valve springs are intact. If any
one is broken, all should be renewed. Check
the free height of the springs against new
ones. If some springs are not long enough,
replace them all. Springs suffer from fatigue
and it is a good idea to renew them even if
they look serviceable. 8The cylinder head can be checked for
warping either by placing it on a piece of plate
glass or using a straight-edge and feeler
blades. If there is any doubt or if its block face
is corroded, have it re-faced by your dealer or
motor engineering works.
9On 1.8 and 2.0 litre, always renew the
sealing ring between the cylinder head and
the thermostat housing when the head is
removed for overhaul (see illustration).
Reference to Chapter 21 will show that a
considerable amount of work is involved if it is
wished to renew the sealing ring with the
cylinder head installed.
10If the oil pressure regulating valve in the
cylinder head is to be renewed, access is
gained through the circular plug covering the
end of the valve (see illustration). The old
valve must be crushed, then its remains
extracted, and a thread (M10) cut in the valve
seat to allow removal using a bolt. A new
valve and plug can then be driven into
position. In view of the intricacies of this
operation, it is probably best to have the valve
renewed by a Vauxhall dealer if necessary.
24Hydraulic valve lifters -
inspection
4
Inspection
1On engines that have covered a high
mileage, or for which the service history
(particularly oil changes) is suspect, it is
possible for the valve lifters to suffer internal
contamination. In extreme cases this may
result in increased engine top end noise and
wear. To minimise the possibility of problems
occurring later in the life of the engine, it is
advisable to dismantle and clean the hydraulic
valve lifters as follows whenever the cylinder
head is overhauled. Note that no spare parts
are available for the valve lifters, and if any of
the components are unserviceable, the
complete assembly must be renewed (see
illustration).
2With the cylinder head removed and
dismantled as described in Sections 21 and
23, first inspect the valve lifter bores in the
2A•24SOHC engine procedures
23.10 Oil pressure regulating valve (1) and
plug (2) - 2.0 litre engine23.9 Renewing the thermostat housing
sealing ring - 2.0 litre engine
Warning: The exhaust valves
fitted to 20 XEJ and C 20 XE
(DOHC) models are fitted with
sodium to improve their heat
transfer. Sodium is a highly reactive
metal, which will ignite or explode
spontaneously on contact with water
(including water vapour in the air). These
must NOT be disposed of with ordinary
scrap. Seek advice from a Vauxhall dealer
or your Local Authority, if the valves are to
be disposed of.