OPEL VECTRA 1988 Service Repair Manual

8Loosen the securing bolt and release the
timing belt tensioner pulley, then slide the belt
from the sprockets and pulleys (see
illustration).
9If desired, the sprockets, tensioner and idler
pulleys, and the rear timing belt cover can be
removed as follows, otherwise go on to
paragraph 27.
10To remove the camshaft sprockets, first
disconnect the breather hoses from the
camshaft cover (see illustration).
11Extract the two securing bolts and remove
the spark plug cover (see illustration), then
disconnect the HT leads from the spark plugs,
and unclip them from the end of the camshaft
cover. If necessary, mark the HT leads for
position, to avoid confusion when refitting.
12Unscrew the twenty securing bolts and
withdraw the camshaft cover (see
illustration).13Recover the one-piece rubber gasket (see
illustration).
14Prevent the relevant camshaft from
turning by holding it with a spanner on the
flats provided in front of No 1 cam lobe, and
unscrew the camshaft sprocket bolt (see
illustration).
15Withdraw the sprocket from the end of the
camshaft, then repeat the procedure for the
remaining camshaft sprocket.
16Remove the crankshaft sprocket. It will be
necessary to prevent the crankshaft from
turning by bolting a metal bar to the sprocket
using two of the crankshaft pulley bolts, or by
jamming the flywheel ring gear teeth. A Torx
socket will be required to unscrew the
sprocket bolt -take care, as the bolt is very
tight. If necessary, use a two-legged puller to
remove the sprocket. Recover the
thrustwashers from the end of the crankshaft,
and from under the bolt head.17To remove the belt tensioner pulley,
simply unscrew the securing bolt from the
centre of the pulley, then withdraw the pulley
complete with mounting plate (see
illustration). Recover the spacer sleeve from
the pulley bolt.
18To remove the belt idler pulley, unscrew
the securing bolt from the centre of the pulley,
then withdraw the pulley and recover the
spacer sleeve from the pulley bolt.
19The rear timing belt cover can now be
removed after unscrewing the upper and
middle studs for the timing belt outer cover
screws. Note that the upper stud simply
unscrews from the cylinder head, but the
middle stud is secured by a bolt. Unscrew the
two upper and single lower right-hand rear
belt cover securing bolts, and withdraw the
rear belt cover (see illustrations).
Refitting
20Refit the rear timing belt cover using a
reversal of the removal procedure.
21Refit the belt idler and tensioner pulleys,
noting that the spacer sleeves should be fitted
with their smaller diameters against the
pulleys (see illustration). Do not fully tighten
the tensioner pulley bolt at this stage.
22Refit the thrustwasher to the end of the
crankshaft, then refit the crankshaft sprocket.
2B•4DOHC engine procedures
4.7 Crankshaft pulley and securing bolts
viewed through right-hand wheel arch4.10 Disconnecting a breather hose from
the rear of the camshaft cover
4.17 Timing belt pulley components
1 Tensioner pulley securing bolt
2 Tensioner pulley mounting plate
3 Idler pulley securing bolt
4.14 Spanner positioned to counterhold
exhaust camshaft4.13 Camshaft cover removed to show
one-piece rubber gasket
4.12 Unscrewing a camshaft cover
securing bolt4.11 Removing the spark plug cover
4.8 Timing belt tensioner pulley securing
bolt (arrowed)

Apply a little grease to the threads of the
securing bolt, and tighten it to the specified
torque in the two stages given in the Specifi-
cations. Ensure that the thrustwasher is in
place under the bolt head, and prevent the
crankshaft from turning as during removal.
23Refit the camshaft sprockets. Ensure that
the locating pins on the ends of the camshafts
engage with the holes in the sprockets and
with the sprocket timing marks facing
forwards. Then tighten the securing bolts to
the specified torque in the two stages given in
the Specifications. Prevent the camshafts
from turning as during removal.
24Check the condition of the camshaft
cover rubber gasket and renew if necessary,
then refit the camshaft cover and tighten the
securing bolts (see illustration).
25Refit the HT leads to the spark plugs
(ensuring that they are refitted to their correct
cylinders), then clip the leads to the end of the
camshaft cover. Refit the spark plug cover
and tighten the securing bolts.
26Reconnect the breather hose to the
camshaft cover.
27Temporarily refit the crankshaft pulley,
and ensure that the crankshaft pulley and
camshaft sprocket timing marks are still
aligned as described in paragraph 6. Then fit a
new timing belt around the sprockets and
pulleys, starting at the crankshaft sprocket.
28Refit the crankshaft pulley, and tighten the
securing bolts to the specified torque. If
necessary, prevent the crankshaft from
turning as during removal. 29Adjust the timing belt tension, as
described from paragraph 35 onwards.
30Refit the outer timing belt cover, ensuring
that the rubber grommets are in place in the
screw holes, and tighten the securing screws.
31Refit the alternator drivebelt and adjust
the drivebelt tension, as described in Chapter
5.
32Refit the power steering pump drivebelt
and adjust the drivebelt tension, as described
in Chapter 10.
33Refit the air cleaner components as
applicable, referring to Chapter 4B, if
necessary.
34Reconnect the battery negative lead.
Adjustment
Note: The manufacturers specify the use of
special adjustment wrench Vauxhall tool No
KM-666 for adjusting the timing belt tension. If
access to this tool cannot be obtained an
approximate adjustment can be achieved
using the method described in this Section.
However it is emphasised that the vehicle
should be taken to a dealer at the earliest
possible opportunity to have the tension
adjusted using the special tool. Do not drive
the vehicle over any long distance until the
belt tension has been adjusted by a dealer
Approximate adjustment
35No checking of timing belt adjustment is
specified, and the following adjustment
procedure applies to a newly fitted belt. The
adjustment must be carried out with the
engine cold.36With the timing belt cover removed and
the tensioner pulley bolt slackened, ensure
that the TDC marks on the camshaft
sprockets and the crankshaft pulley are
aligned as described in paragraph 6. If
necessary, turn the crankshaft to achieve
alignment.
37Have an assistant press the tensioner
pulley against the belt until the belt can just be
twisted through 45°, using moderate pressure
with the thumb and forefinger, on the longest
belt run between the exhaust camshaft
sprocket and the belt idler pulley.
38Have the assistant hold the tensioner
pulley in position, and tighten the tensioner
pulley bolt to the specified torque in the two
stages given in the Specifications.
39Turn the crankshaft clockwise through
two complete revolutions, 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.
40Proceed as described in paragraphs 30 to
34, inclusive.
41Have the belt tension adjusted by a
Vauxhall dealer using the manufacturer’s
special tool at the earliest opportunity.Adjustment using Vauxhall special
tool (KM-666)
42Proceed as described in paragraphs 35
and 36.
43Fit the special tool KM-666 to the belt
tensioner pulley mounting plate, in
accordance with the tool manufacturer’s
instructions.
44Working anti-clockwise from the TDC
mark on the exhaust camshaft sprocket, mark
the seventh tooth on the sprocket (see
illustration).
45Turn the crankshaft clockwise until this
tooth is aligned with the TDC notch in the
camshaft cover. The crankshaft must be
turned evenly and without jerking, to prevent
the timing belt from jumping off the sprockets
and pulleys.
46Tighten the tensioner pulley bolt to the
specified torque in the two stages given in the
Specifications.
47Remove the special tool.
DOHC engine procedures 2B•5
4.21 Belt tensioner pulley and spacer
sleeve. Note that smaller diameter of
spacer sleeve fits against pulley
4.44 Working anti-clockwise from the TDC
mark on the exhaust camshaft sprocket,
mark the seventh tooth on the sprocket4.24 Tightening a camshaft cover securing
bolt
4.19B Rear timing belt cover lower right-
hand securing bolt4.19A Timing belt outer cover screw upper
stud (1) and rear belt cover upper
securing bolts (2)
2B

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)

pitting. If evident, the cylinder head and all
bearing caps must be renewed as a matched
set, as there is no provision for refacing if the
bearing caps cannot be renewed individually.
8The camshaft(s) should show no marks or
scoring on the journal or cam lobe surfaces. if
evident, renew the camshaft(s).
9It is advisable to renew the camshaft front
oil seal(s) as a matter of course. Prise the old
seal(s) from the front of the camshaft(s) and
discard them.
Refitting
10Begin refitting by liberally coating the
contact faces of the hydraulic valve lifters and
the camshaft(s) with molybdenum disulphide
paste.
11Coat the mating faces of the front and
rear bearing caps with sealing compound and
refit the bearing caps in their original positions
as noted during removal.
12Tighten the camshaft bearing cap nuts to
the specified torque in half-turn stages, as
when loosening the nuts. Note that when
refitting the exhaust camshaft, the two smaller
rear bearing cap securing nuts should be
tightened after all the main camshaft bearing
cap nuts have been tightened. Note also that
the two smaller nuts should be tightened to a
lower torque wrench setting than the main
nuts.
13Turn the camshaft until the locating peg
for the camshaft sprocket is uppermost, then
lubricate the lips of a rear 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.
14Repeat the procedure for the remaining
camshaft.
15Refit the distributor with reference to
Chapter 5. Fit a new timing belt and the
camshaft sprockets, then adjust the timing
belt as described in Section 4 or 5, as
applicable.
8Cylinder 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, a new cylinder head gasket and a
new timing belt must be used on refitting.
The torque settings (as shown in Chapter 2A)
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 3.3Remove the front section of the exhaust
system, as described in Chapter 4C.
4The cylinder head can be removed
complete with the inlet manifold, or the inlet
manifold can be detached from the cylinder
head before removal, with reference to
Chapter 4B. If no work is to be carried out on
the inlet manifold, it can be unbolted from the
cylinder head and 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 inlet manifold, disconnect
all relevant hoses, pipes and wiring from the
inlet manifold and associated components,
referring to Chapter 4B, and unbolt the
manifold support bracket from the 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 17.
7Disconnect the wiring plug from the airflow
meter, and the breather hose from the air box
on the throttle body. Disconnect the air
cleaner trunking and remove the airflow
meter/air box assembly from the throttle
body. Refer to Chapter 4B if necessary.
8Disconnect the end of the throttle cable
from the throttle valve lever, then unbolt the
throttle cable support bracket and remove it
from the inlet manifold.
9Unscrew the two earth lead securing nuts
from the fuel rail (one at each end of the rail)
and disconnect the three earth leads.
10Disconnect the wiring plug from the
throttle position switch.
11Pull up on the wiring harness housing, and
disconnect the wiring plugs from the fuel
injectors by compressing the retaining clips.
Move the wiring harness housing to one side.
12Disconnect the two breather hoses from
the rear of the camshaft cover.
13Loosen the alternator mountings, with
reference to Chapter 5, then unbolt the upper
alternator mounting from the inlet manifold.
14Unbolt the manifold support bracket from
the manifold.15Make a final check to ensure that all
necessary hoses, pipes and wires have been
disconnected, then unscrew the securing nuts
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.
16Recover the manifold gasket from the
cylinder head.
17Remove the timing belt, camshaft
sprockets, and timing belt tensioner and idler
pulleys, as described in Section 4.
18Unscrew the upper and middle studs for
the timing belt outer cover screws. Note that
the upper stud simply unscrews from the
cylinder head, but the middle stud is secured
by a bolt.
19Unscrew the two upper rear timing belt
cover securing bolts from the cylinder head.
20Remove the distributor cap and HT leads
with reference to Chapter 5.
21Disconnect the distributor wiring plug.
22Disconnect the coolant hose from the
left-hand end of the cylinder head.
23Unscrew the bolt securing the crankcase
breather tube bracket to the end of the
cylinder head.
24Disconnect the radiator top hose from the
thermostat housing, and disconnect the
wiring plugs from the temperature gauge
sender and the coolant temperature sensor
(both situated in the thermostat housing).
25Make a final check to ensure that all
relevant hoses, pipes and wires have been
disconnected.
26On X20 XEV models, remove the
camshaft, as described in Section 7.
27Using a Torx socket, and working in the
order shown (see illustrations), 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. Note that the loosening sequence
on X20 XEV differs to other DOHC engines.
28Lift the cylinder head from the cylinder
block. 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.
DOHC engine procedures 2B•7
8.27B Cylinder head bolt loosening
sequence - (X 20 XEV engines)8.27A Cylinder head bolt loosening
sequence - (20 XEJ and C 20 XE engines)
2B

29Recover the cylinder head gasket and
discard it.
30Clean the cylinder head and block mating
faces by careful scraping. Take care not to
damage the cylinder head, which is made of
light alloy and is easily scored. Cover the
coolant passages and other openings with
masking tape or rag, to prevent dirt and
carbon falling in. Mop out all the oil from the
bolt holes; if oil is left in the holes, hydraulic
pressure could crack the block when the bolts
are refitted.
31If desired, the cylinder head can be
dismantled and inspected as described in
Section 10.
Refitting
32Begin refitting by locating a new gasket
on the block so that the word “OBEN” or
“TOP” is uppermost at the timing belt end of
the engine.
33With the mating faces scrupulously clean,
locate the cylinder head on the block so that
the positioning dowels engage in their holes.
34Temporarily refit the crankshaft pulley and
the camshaft sprockets, and ensure that the
timing marks are still positioned as they were
before the timing belt was removed (see
Section 4).35Fit the new cylinder head bolts, ensuring
that the washers are in place under their
heads, and screw the bolts in by hand as far
as possible.
36Tighten the bolts in the order shown (see
illustrations). Note that the tightening
sequence on X20 XEV differs to other DOHC
engines. Tighten the bolts in the four stages
given in the Specification (see Chapter 2A, as
2.0 litre) - i.e. tighten all bolts to the Stage 1
torque, then tighten all bolts to Stage 2 and so
on (see illustrations).
37Further refitting is a reversal of the
removal procedure, remembering the
following points.
38Refit the timing belt tensioner and idler
pulleys, camshaft sprockets and a new timing
belt as described in Section 4, and tension the
timing belt as described in Sections 4 and 5.
39Where applicable, refit the inlet manifold
to the cylinder head with reference to Chapter
4B, using a new gasket.
40Refit the front section of the exhaust
system as described in Chapter 4C, using a
new gasket.
41Refit the upper alternator mounting to the
inlet manifold (where applicable), then adjust
the alternator drivebelt tension, as described
in Chapter 5.
42Refill the cooling system, (Chapter 3).43On completion, check that all relevant
hoses, pipes and wires, etc., have been
reconnected.
44When the engine is started, check for
signs of leaks.
45Once the engine has reached normal
operating temperature, check and if
necessary adjust the mixture (where
applicable) with reference to Chapter 4B.
9Cylinder head -removal and
refitting (engine removed)
4
Note: New cylinder head bolts, a new cylinder
head gasket, and a new timing belt must be
used on refitting.
The torque settings (as shown in Chapter 2A)
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 inlet manifold, or the inlet
manifold can be detached from the cylinder
head before removal, with reference to
Chapter 4B.
2Proceed as described in Section 8,
paragraphs 17 to 19 inclusive.
3If not already done, remove the distributor
cap and HT leads, referring to Chapter 5.
2B•8DOHC engine procedures
8.36A Cylinder head bolt tightening sequence -
20 XEJ and C 20 XE engines
8.36C Tighten the cylinder head bolts to
the specified torque . . .8.36D . . .and then through the specified
angle
8.36B Cylinder head bolt tightening sequence -
X 20 XEV engines
Warning: The exhaust valves
fitted to 20 XEJ and C 20 XE
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.

4Unscrew the bolt securing the crankcase
breather tube bracket to the end of the
cylinder head.
5Make a final check to ensure that all
relevant hoses, pipes and wires have been
disconnected.
6Continue as described in Section 8,
paragraphs 26 to 31.
Refitting
7Proceed as described in Section 8,
paragraphs 32 to 38 inclusive but in addition
note the following.
8On completion, check that all relevant
hoses, pipes and wires, etc., have been
reconnected.
10Cylinder head- dismantling
and reassembly
4
Dismantling
1With the cylinder head removed as
described in Section 8, clean away all external
dirt.
2If not already done, remove the thermostat
housing and thermostat as described in
Chapter 3, and remove the manifolds as
described in Chapters 4B and 4C.
3Remove the spark plugs (if not already
done), and remove the distributor with
reference to Chapter 5.
4Remove the camshafts as described in
Section 7.
5Remove the hydraulic valve lifters from their
bores using a rubber suction plunger tool - do
not invert the cylinder head to remove the
valve lifters. Keep the valve lifters upright at all
times (oil groove at bottom (see illustration)),
and immerse them in order of removal in a
container of clean engine oil until they are to
be refitted.
6To remove the valve components, continue
as described in Chapter 2A, Section 22,paragraphs 3 to 7 inclusive.
7The cylinder head and valves can be
inspected for wear and damage as described
in Chapter 2A, Section 23.
Reassembly
8With all components cleaned, refit the valve
components as described in Chapter 2A,
Section 22, paragraphs 10 to 19 inclusive.
9Refit the hydraulic valve lifters to the
cylinder head in their original positions.
Liberally oil the valve lifter bores, and if new
lifters are being fitted, initially immerse each
one in a container of clean engine oil and
compress it (by hand) several times to charge
it.
10Refit the camshafts, as described in
Section 7.
11Refit the spark plugs if desired, and refit
the distributor with reference to Chapter 5.
12Where applicable, refit the manifolds
and/or the thermostat and housing.
13Refit the cylinder head, as described in
Sections 8 and 9, as applicable.
11Valve lifters- general
Although the valve lifters on these engines
cannot be dismantled they should be carefully
inspected for obvious signs of wear on the
contact faces. Also check the valve lifter oil
holes for obstructions and for any signs of oil
sludge build-up. If excessive wear is evident
(this is unlikely), all the valve lifters must be
renewed as a set.
12Crankshaft front oil seal -
renewal
3
1The procedure is similar to SOHC models(see Chapter 2A), noting the following points.
2The spacer ring (if fitted), from the end of
the crankshaft, must be removed, before
refitting.
3After fitting the new seal, coat the oil pump
mating face of the spacer ring with sealing
compound, then push the spacer ring onto
the end of the crankshaft, until it is seated
against the oil pump.
4The timing belt should be renewed.
5Refit the rear timing belt cover and the
timing belt, as described in Section 4. Adjust it
as described in Section 4 and 5.
13Sump - removal and refitting
3
Note: Sump gaskets, cannot be reused.
Ensure that new gaskets are obtained before
removing the sump
Removal
1The procedure is similar to SOHC models
(see Chapter 2A), with the following variations.
2The engine undershield must be removed.
3Remove both the cork gaskets and clean all
sealing surfaces, scrupulously.
Refitting
4Locate a new gasket on the cylinder block,
if necessary applying a little sealing
compound to hold it in place.
5Locate the remaining new gasket on the
sump baffle, but do not use sealing
compound.
14Oil pump - removal and
refitting
3
Removal
1Apart from the following variations, the
procedure is the same as for SOHC models.
2If the engine is still in the vehicle,
disconnect the oil cooler pipe unions from the
oil pump, and move the pipes to one side out
DOHC engine procedures 2B•9
14.2 Oil cooler pipe unions at oil pump
10.5 Remove the hydraulic valve lifters using a rubber plunger. Inset (A) shows valve
lifter upright, with oil groove (arrowed) at bottom
2B

of the way (see illustration).
3Remove the spacer ring from the end of the
crankshaft (see illustration).
Refitting
4Coat the oil pump mating face of the spacer
ring with sealing compound, then push the
spacer ring onto the end of the crankshaft
until it is seated against the oil pump.
5The timing belt should be renewed, see
Sections 4 and 5, for details.
6Remember also to reconnect the oil cooler
pipes to the oil pump, and tighten the unions.
15Oil cooler - removal and
refitting
3
Removal
1To gain sufficient access to remove the oil
cooler, the radiator must be removed (as
described in Chapter 3). Alternatively, the
front bumper can be removed, as described in
Chapter 11 (see illustration).
2With the appropriate component(s)removed for access, unscrew the oil cooler
pipe unions from the oil cooler. Be prepared
for oil spillage, and plug the open ends of the
pipes, to prevent further oil leakage and dirt
ingress.
3Unscrew the two securing nuts, and
withdraw the oil cooler from its mounting
brackets.
Refitting
4Refitting is a reversal of removal, but on
completion, check and if necessary top-up
the engine oil level, as described in Chapter 1.
2B•10DOHC engine procedures
15.1 Oil cooler viewed through front spoiler. Securing nuts
arrowed14.3 Oil pump securing bolts (arrowed) and crankshaft spacer
ring (A)

2A
General
Type
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Four-cylinder, in-line, water-cooled, transversely mounted at front of
vehicle. Single belt-driven overhead camshaft, acting on hydraulic
valve lifters
Manufacturer’s engine codes:
14 NV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4 litre (1389 cc)
16 SV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 litre (1598 cc)
X16 SZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 litre (1598 cc) ‘Ecotec’ type engine
C16 NZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 litre (1598 cc) + catalyst
C16 NZ2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 litre (1598 cc) + catalyst
18 SV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 litre (1796 cc)
C18 NZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 litre (1796 cc) + catalyst
20 NE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 litre (1998 cc)
20 SEH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 litre (1998 cc) + early SRi
C20 NE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 litre (1998 cc) + catalyst
Pistons:Bore (mm) Stroke (mm)
14 NV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77.6 73.4
16 SV, C16 SV, C16 NZ and X16 SZ . . . . . . . . . . . . . . . . . . . . . . . . . 79.0 81.5
C16 NZ2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80.0 79.5
18 SV and C18 NZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.8 79.5
20 NE, 20 SEH and C20 NE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86.0 86.0
Chapter 2 Part A:
SOHC engine procedures
Camshaft front oil seal - removal and refitting . . . . . . . . . . . . . . . . . .15
Camshaft housing and camshaft - general . . . . . . . . . . . . . . . . . . . .17
Camshaft housing and camshaft - dismantling, inspection and
reassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Camshaft rear oil seal - removal and refitting . . . . . . . . . . . . . . . . . . .16
Camshafts, “undersize” C16 NZ2, 1.8 and 2.0 litre engines -
general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Compression test - description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Crankcase ventilation system - description and maintenance . . . . . . .2
Crankshaft and bearings - examination . . . . . . . . . . . . . . . . . . . . . . .35
Crankshaft and bearings - removal and refitting . . . . . . . . . . . . . . . .34
Crankshaft front oil seal - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Crankshaft rear oil seal - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Cylinder block and bores - examination and renovation . . . . . . . . . .36
Cylinder head - dismantling and reassembly . . . . . . . . . . . . . . . . . . .22
Cylinder head - inspection and renovation . . . . . . . . . . . . . . . . . . . . .23
Cylinder head - removal and refitting (engine in vehicle) . . . . . . . . . .20
Cylinder head - removal and refitting (engine removed) . . . . . . . . . . .21
Engine - removal and refitting (leaving transmission in car) . . . . . . . . .7
Engine and transmission mountings - renewal . . . . . . . . . . . . . . . . . . .9
Engine and transmission - removal, separation, reconnection and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Engine oil and filter - renewal . . . . . . . . . . . . . . . . . . . . .See Chapter 1Engine dismantling and reassembly - general . . . . . . . . . . . . . . . . . .10
Examination and renovation - general . . . . . . . . . . . . . . . . . . . . . . . .37
Flexplate (automatic transmission) - removal and refitting . . . . . . . . .26
Flywheel - removal, inspection and refitting . . . . . . . . . . . . . . . . . . . .25
General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Hydraulic valve lifters - inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Initial start-up after major overhaul or repair . . . . . . . . . . . . . . . . . . .38
Major operations possible with the engine in the vehicle . . . . . . . . . . .4
Major operations requiring engine removal . . . . . . . . . . . . . . . . . . . . .5
Method of engine removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Oil pump - dismantling, inspection and reassembly . . . . . . . . . . . . .31
Oil pump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Pistons and connecting rods - examination and renovation . . . . . . .33
Pistons and connecting rods - removal and refitting . . . . . . . . . . . . .32
Sump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Timing belt and sprockets (without automatic tensioner) - removal,
refitting and adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Timing belt and tensioner 1.4 and 1.6 models (not C16 NZ2) - removal,
refitting and adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Timing belt and tensioner C16 NZ2, 1.8 and 2.0 litre - removal, refitting
and adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Timing belt cover aperture, 1.4 and 1.6 models - general . . . . . . . . .13
2A•1
Specifications Contents
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert DIY
or professional
Degrees of difficulty
54321

Compression ratio
14 NV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9.4 : 1
16 SV, X16 SZ, 18 SV and 20 SEH . . . . . . . . . . . . . . . . . . . . . . . . . .10.0 : 1
C16 NZ, C16 NZ2, C18 NZ, 20 NE and C20 NE . . . . . . . . . . . . . . . . .9.2 : 1
Maximum power:
14 NV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55 kW (75 bhp) at 5600 rpm
16 SV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60 kW (82 bhp) at 5400 rpm
X16 SZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52 kW (71 bhp) at 5000 rpm
C16 NZ and C16 NZ2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55 kW (75 bhp) at 5200 rpm
18 SV and C18 NZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66 kW (90 bhp) at 5400 rpm
20 NE and C20 NE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85 kW (116 bhp) at 5200 rpm
20 SEH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95 kW (129 bhp) at 5600 rpm
Maximum torque:
14 NV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108 Nm at 3000 rpm
X16 SZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .128 Nm at 2800 rpm
16 SV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .130 Nm at 2600 rpm
C16 NZ and C16 NZ2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125 Nm at 2800 rpm
18 SV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .148 Nm at 2800 rpm
C18 NZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145 Nm at 3000 rpm
20 NE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .175 Nm at 2600 rpm
20 SEH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .180 Nm at 4600 rpm
C20 NE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .170 Nm at 2600 rpm
Firing order:
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3-4-2 (No 1 cylinder at timing belt end)
Cylinder block:
Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Cast iron
Maximum permissible bore out-of round . . . . . . . . . . . . . . . . . . . . . .0.013 mm
Maximum permissible bore taper . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.013 mm
Maximum permissible rebore oversize . . . . . . . . . . . . . . . . . . . . . . . .0.5 mm
Crankshaft and bearings
Number of main bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Main bearing journal diameter (mm):
14 NV, 16 SV, C16 NZ and X16 SZ
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54.980 to 54.997
0.25mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54.730 to 54.747
0.50mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54.482 to 54.495
C16 NZ2, 18 SV, C18 NZ, 20 NE, C20 NE and 20 SEH
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57.974 to 57.995
0.25mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57.732 to 57.745
0.50mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57.482 to 57.495
Main bearing shell colour codes:Bearing cap shellsCylinder block shells
14 NV, 16 SV, C16 NZ and X16 SZ
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .BrownGreen
0.25 mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Brown/blueGreen/blue
0.50 mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Brown/whiteGreen/white
C16 NZ2, 18 SV, C18 NZ, 20 NE, C20 NE and 20 SEH
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Brown/green/white
0.25mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Brown/blue and Green/blue
0.50mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Brown/white and Green/white
Centre (thrust) main bearing journal width (mm):
14 NV, 16 SV, C16 NZ and X 16 SZ
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26.000 to 26.052
0.25mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26.200 to 26.252
0.50mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26.400 to 26.452
C16 NZ2, 18 SV, C18 NZ, 20 NE, C20 NE and 20 SEH
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25.950 to 26.002
0.25mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26.150 to 26.202
0.50mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26.350 to 26.402
Big-end bearing journal diameter (mm):
14 NV, 16 SV, C16 NZ and X16 SZ
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42.971 to 42.987
0.25mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42.721 to 42.737
0.50mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42.471 to 42.487
C16 NZ2, 18 SV, C18 NZ, 20 NE, C20 NE and 20 SEH
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48.970 to 48.988
0.25mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48.720 to 48.738
0.50mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48.470 to 48.488
2A•2SOHC engine procedures

Crankshaft and bearings (continued)
Big-end bearing shell colour codes (all models):
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .None
0.25 mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Blue
0.50 mm undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .White
Main and big-end bearing journal out-of-round (all models) . . . . . . . . .0.04 mm maximum
Main bearing permissible movement (mm):
14 NV, 16 SV, C16 NZ and X16 SZ . . . . . . . . . . . . . . . . . . . . . . . . . . .0.017 to 0.047
C16 NZ2, 18 SV, C18 NZ, 20 NE, C20 NE and 20 SEH . . . . . . . . . . .0.015 to 0.040
Big-end bearing permissible movement (mm):
14 NV, 16 SV, C16 NZ and X16 SZ . . . . . . . . . . . . . . . . . . . . . . . . . . .0.019 to 0.071
C16 NZ2, 18 SV, C18 NZ, 20 NE, C20 NE and 20 SEH . . . . . . . . . . .0.006 to 0.031
Crankshaft endfloat (mm):
14 NV, 16 SV, C16 NZ and X16 SZ . . . . . . . . . . . . . . . . . . . . . . . . . . .0.1 to 0.2
C16 NZ2, 18 SV, C18 NZ, 20 NE, C20 NE and 20 SEH . . . . . . . . . . .0.050 to 0.152
Connecting rod endfloat (mm) (all models) . . . . . . . . . . . . . . . . . . . . . . .0.07 to 0.24
Piston and cylinder bores (Ø in mm)Bore diameterPiston diaID mark
14 NV:
Production size 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77.5677.546
77.5777.557
77.5877.568
Production size 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77.5977.5799
77.6077.5800
77.6177.5901
77.6277.6002
0.5 mm oversize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78.0778.057 + 0.5
16 SV, C16 NZ and X16 SZ:
Production size 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78.9578.935
78.9678.946
78.9778.957
78.9878.968
Production size 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78.9978.9799
79.0078.9800
79.0178.9901
79.0279.0002
Production size 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79.0379.0103
79.0479.0204
79.0579.0305
79.0679.0406
Production size 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79.0779.0507
79.0879.0608
79.0979.0709
79.1079.081
0.5 mm oversize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79.4879.457 + 0.5
C16 NZ2:
Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79.98n/a98
79.90n/a99
80.00n/a00
80.01n/a01
80.02n/a02
18 SV and C18 NZ:
Production size 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84.78 mm84.76 mm8
Production size 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84.79 mm84.77 mm99
84.80 mm84.78 mm00
84.81 mm84.79 mm01
84.82 mm84.80 mm02
0.5 mm oversize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85.27 mm85.25 mm7 + 0.5
20 NE, C20 NE and 20 SEH:
Production size 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85.98 mm85.96 mm8
Production size 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85.99 mm85.97 mm99
86.00 mm85.98 mm00
86.01 mm85.99 mm01
86.02 mm86.00 mm02
0.5 mm oversize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86.47 mm86.45 mm7 + 0.5
Piston clearance in bore (mm) (all models) . . . . . . . . . . . . . . . . . . . . . . .0.02 to 0.04
SOHC engine procedures 2A•3
2A