a)Inlet and exhaust manifolds (where
applicable)
b)Starter motor
c)Rear coolant gallery and hoses
d)Oil pressure switch
e)Oil temperature switch (where applicable)
f)Oil level sensor (where applicable)
g)Knock sensor (where applicable)
h)TDC sensor (where applicable)
i)Distributor components
j)Fuel pump (where applicable)
k)Thermostat/housing (N 16 NZ2, 1.8 and
2.0 litre models)
l)Power steering pump and mounting
bracket (where applicable)
m)Alternator mounting bracket
n)Engine lifting brackets
o)Dipstick/crankcase breather tube
p)Inlet manifold mounting bracket (where
applicable)
13To ensure maximum life, with minimum
trouble, from a rebuilt engine, not only must
everything be correctly assembled, but it must
also be spotlessly clean. All oilways and
coolant passages must be clear, and all
washers must be fitted in their original
positions. Oil all bearings and other moving
surfaces thoroughly with clean engine oil
during assembly.
14Before assembly begins, renew any bolts
or studs with damaged threads.
15Obtain a torque wrench, an angle-torque
gauge, sockets and bits, an oil can, clean
lint-free rag, and a set of engine gaskets and
oil seals, together with a new oil filter.16If they have been removed, new cylinder
head bolts, flywheel bolts, big-end bearing
cap bolts and main bearing cap bolts will also
be required.
17On completion of reassembly, refit the
applicable ancillary components listed in
paragraph 12.
18Follow procedure shown in Section 37.
11Timing belt and sprockets
(without automatic tensioner) -
removal, refitting and adjustment
3
Note: A two-legged puller may be required to
remove the crankshaft sprocket on N 16 NZ2,
1.8 and 2.0 litre models.Some of the later 1.4
and 1.6 litre engines, identifiable by the
squared-off top surfaces of the timing belt
covers, are fitted with spring-loaded auto-matic timing belt tensioners to ensure correct
belt tensioning on assembly.
Removal
1Disconnect the battery negative lead.
2On models with power steering, remove the
pump drivebelt, see Chapters 1 and 10.
3Remove the alternator drivebelt, as
described in Chapter 5.
4On C 16 NZ2, 1.8 and 2.0 litre models,
disconnect the wiring from the temperature
gauge sender.
5Release the securing clips (or hexagon-
headed screws, if fitted), and remove the main
outer timing belt cover, then unclip the smaller
outer timing belt cover from the coolant pump.
Where applicable, three screws retain the lower
(small) outer cover to the rear cover, the fourth
secures the tensioner (see illustrations).
6On 1.6 litre models with power steering,
remove the power steering pump, as
described in Chapter 10.
7Turn the crankshaft using a socket or
spanner on the crankshaft sprocket bolt, until
the timing mark on the camshaft sprocket is
aligned with the notch in the rear timing belt
cover, and the notch in the crankshaft pulley
is aligned with the pointer on the rear timing
belt cover (see illustrations). Note that on 1.4
litre engine there are two notches in the
crankshaft pulley, representing 5°and 10°
BTDC, and the 10°BTDC notch should be
aligned with the pointer (see illustration).
8Loosen the three coolant pump securing
bolts (see illustration), and turn the pump to
relieve the tension in the timing belt, then slide
the belt from the camshaft sprocket.
SOHC engine procedures 2A•13
11.5C Timing belt lower (small) outer
cover screws (A), tensioner screw (B),
ignition timing fixed reference mark (C)
11.8 Loosening a coolant pump securing
bolt - 2.0 litre engine11.7C Crankshaft pulley 10°BTDC notch
aligned with pointer on rear timing belt
cover - 1.4 litre engine11.7B . . .and notch in crankshaft pulley
aligned with pointer on rear timing belt
cover - 2.0 litre engine
11.7A Camshaft sprocket TDC mark
aligned with notch in rear timing belt
cover . . .
11.5B . . .and the smaller cover from the
coolant pump - 2.0 litre engine11.5A Remove the main outer timing belt
cover . . .
2A
9The crankshaft pulley must now be
removed. On 1.4 and 1.6 litre engines (except
C 16 NZ2), the pulley is secured by a single
bolt, which also secures the crankshaft
sprocket. On C 16 NZ2, 1.8 and 2.0 litre
engines, the pulley is secured by four bolts,
which must be unscrewed using an Allen key
or hexagon bit. On manual transmission
models, if the engine is in the vehicle, the
crankshaft can be prevented from turning by
having an assistant engage first gear and
depress the brake pedal. Alternatively, the
flywheel ring gear teeth can be jammed using
a large screwdriver or similar tool.
10With the crankshaft pulley removed, the
timing belt can be withdrawn.
11If desired, the sprockets and the rear
timing belt cover can be removed as follows,
otherwise go on to paragraph 23.
12To remove the camshaft sprocket, firstdisconnect the breather hose(s) from the
camshaft cover, then unscrew the securing
bolts noting the locations of the HT lead
brackets and any other wiring brackets, and
remove the camshaft cover.
13Recover the gasket. Prevent the camshaft
from turning by holding it with a spanner on
the flats provided between No’s 3 and 4
camshaft lobes, and unscrew the camshaft
sprocket bolt.
14Withdraw the sprocket from the end of the
camshaft.
15To remove the crankshaft sprocket on 1.4
and 1.6 litre engines (except C 16 NZ2), if
necessary, remove the lower securing bolts
from the main rear timing belt cover and use
two large screwdrivers behind the cover to
lever off the sprocket. Remove the Woodruff
key if it is loose.
16To remove the crankshaft sprocket on C
16 NZ2, 1.8 and 2.0 litre engines, it will benecessary to prevent the crankshaft from
turning, as described in paragraph 9. Take
care when unscrewing the sprocket bolt, as it
is very tight. If necessary, use a two-legged
puller to remove the sprocket. Recover the
Woodruff key and the thrustwasher from the
end of the crankshaft.
17To remove the main rear timing belt cover
on C 16 NZ2, 1.8 and 2.0 litre models
disconnect the TDC sensor wiring plug and
unclip the wiring from the belt cover. Then
unscrew the two upper securing bolts and the
lower securing bolt(s) (one in the case of C 16
NZ2, 1.8 and 2.0 litre engines, two on other
SOHC engines). Withdraw the cover,
manipulating it from the smaller rear belt
cover on the coolant pump (see illustrations).
18If desired, the smaller rear belt cover can
be removed from the coolant pump, after
unscrewing the securing bolt (see
illustration), by rotating it to disengage it from
the retaining flange on the pump.
Refitting
19Refit the rear timing belt cover(s) using a
reversal of the removal procedure, and
ensuring that the main cover engages correctly
with the smaller cover on the coolant pump.
20On C 16 NZ2, 1.8 and 2.0 litre engines,
refit the thrustwasher and the Woodruff key to
the end of the crankshaft. Then refit the
crankshaft sprocket, and tighten the securing
bolt to the specified torque in the two stages
given in the Specifications. Ensure that the
washer is in place under the bolt head, and
prevent the crankshaft from turning as during
removal (see illustrations).
2A•14SOHC engine procedures
11.17A Loosening the main rear timing
belt cover lower securing bolt -
2.0 litre engine11.18 Unscrewing the coolant pump rear
belt cover securing bolt - 2.0 litre engine
11.20E Tighten the bolt to the specified
torque . . .11.20D . . .and the washer and bolt11.20C . . .the crankshaft sprocket . . .
11.20B . . . the Woodruff key . . .11.20A Refit the thrustwasher . . .
11.17B Main rear timing belt cover lower
securing bolts (arrowed) - 1.6 SV engine
25Flywheel -removal, inspection
and refitting
4
Note: New flywheel securing bolts must he
used on refitting. Certain models are fitted
with a ‘Pot type’ flywheel. Although, it has a
deeply recessed surface for the clutch disc,
the operations below are the same.
Removal
1If not already done, remove the clutch,
(Chapter 6), and the starter motor, (Chapter 5).
2If the engine is in the vehicle, remove the
clutch release bearing and its guide sleeve, as
described in Chapter 6.
3Although the flywheel bolt holes are offset
so that the flywheel can only be fitted in one
position, it will make refitting easier if
alignment marks are made between the
flywheel and the end of the crankshaft.
4Prevent the flywheel from turning by
jamming the ring gear teeth using a large
screwdriver or similar tool. Access is most
easily obtained through the starter motor
aperture if the engine is in the vehicle.
5Unscrew the securing bolts, and remove
the flywheel (see illustration). Take care, as
the flywheel is heavy!
Inspection
6With the flywheel removed, it can be
inspected as follows.
7If the teeth on the flywheel starter ring are
badly worn, or if some are missing, then it will
be necessary to remove the ring and fit a new
one.
8The old ring can be split with a cold chisel,
after making a cut with a hacksaw blade
between two gear teeth. Take great care not
to damage the flywheel during this operation,
and use eye protectors always. Once the ring
has been split, it will spread apart and can be
lifted from the flywheel.
9The new ring gear must be heated to 180 to
230°C (356 to 446°F) and unless facilities for
heating by oven or flame are available, leave
the fitting to a dealer or motor engineering
works. The new ring gear must not be
overheated during this work, or the temper of
the metal will be altered.10The ring should be tapped gently down
onto its register, and left to cool naturally -the
contraction of the metal on cooling will ensure
that it is a secure and permanent fit.
11If the clutch friction disc contact surface
of the flywheel is scored, or on close
inspection, show’s evidence of small hairline
cracks (caused by overheating), it may be
possible to have the flywheel surface ground.
This is provided that the overall thickness of
the flywheel is not reduced too much. Consult
a specialist engine repairer and if it is not
possible, renew the flywheel complete.
Refitting
12Refitting is a reversal of removal,
remembering the following points.
13Align the previously made marks on the
flywheel and crankshaft, and fit new flywheel
securing bolts. Tighten them to the specified
torque in the two stages given in the Specifi-
cations, whilst preventing the flywheel from
turning, as during removal (see illustrations).
14Where applicable, refit the clutch release
bearing, guide sleeve, and the clutch, as
described in Chapter 6.
26Flexplate (automatic
transmission) -removal and
refitting
4
Removal
1Remove the transmission (Chapter 7B).
2Prevent the flexplate from turning by
jamming its ring gear teeth using a large
screwdriver or similar tool.
3Unbolt and remove the flexplate. Examine
the bolts and renew them all as a set if there is
the slightest doubt about their condition.
4The ring gear can be checked, and renewed
if necessary, as described in Section 25.
Refitting
5Refitting is the reverse of the removal
procedure. If the bolts are to be re-used, use a
wire brush to clean their threads, apply a few
drops of thread-locking compound (Vauxhall
Part No 90167347, or equivalent) to the
threads of each bolt on refitting. Tighten the
bolts to the specified torque wrench setting.6Refit the transmission, refer to Chapter 7B if
necessary.
27Crankshaft front oil seal -
renewal
3
Renewal
1Remove the timing belt and the rear timing
belt cover, as described in Section 11.
2Ensure that the Woodruff key is removed
from the end of the crankshaft.
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. Several attempts
may be necessary. Be careful not to damage
the sealing face of the crankshaft.
4Clean the oil seal seat with a wooden or
plastic scraper.
5Before fitting the new oil seal, steps must
be taken to protect the oil seal lips from
damage, and from turning back on the
shoulder at the front end of the crankshaft.
Grease the seal lips, and then wind tape
around the end of the crankshaft to form a
gentle taper.
6Tap the seal into position using a large
socket or tube, until the seal is flush with the
outer face of the oil pump housing.
7Refit the rear timing belt cover and the
timing belt tension the timing belt as
described in Section 11.
2A•26SOHC engine procedures
25.13C . . .and then through the
specified angle -
1.6 litre engine25.13B Tighten the flywheel securing bolts
to the specified toque . . .25.13A Tool for locking flywheel fitted to
engine-to-transmission bolt hole -
1.6 litre engine
25.5 Removing the flywheel -
1.6 litre engine
28Crankshaft rear oil seal -
renewal
4
Renewal
1With the engine removed from the vehicle,
remove the flywheel, or flexplate (as
applicable) as described in Sections 25 and
26.
2Punch 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. Several attempts
may be necessary. Be careful not to damage
the sealing face of the crankshaft.
3Clean the oil seal seat with a wooden or
plastic scraper.4Grease the lips of the new seal, then tap the
seal into position using a tube, until flush with
the outer faces of the cylinder block and rear
main bearing cap (see illustration).
5Refit the flywheel or flexplate (if applicable),
as described in Sections 25 or 26.
29Sump - removal and refitting
4
Note: The sump gasket(s) must be renewed
on refitting and sealer will be required for use
on the oil pump and rear main bearing
cap-to-cylinder block joints
Removal
1If the engine is in the vehicle, continue as
follows, otherwise go on to paragraph 9.
2Disconnect the battery negative lead.
3Drain the engine oil, referring to Chapter 1 if
necessary, then refit and tighten the drain
plug.
4Apply the handbrake, then jack up the front
of the vehicle, and support securely on axle
stands (see “Jacking and Vehicle Support”).
5Remove the front section of the exhaust
system, as described in Chapter 4C.
6Where applicable, disconnect the wiring
from the oil level sensor.
7Unscrew the securing bolts and remove the
engine-to-transmission blanking plate from
the bellhousing.8Remove the securing bolts, and withdraw
the sump. Note that on most models, the
sump baffle will probably be pulled away from
the cylinder block with the sump, but cannot
be removed until the oil pick-up pipe has been
removed.
9On 1.6, 1.8 and 2.0 litre models, to remove
the sump baffle, it is necessary to unbolt the
bracket securing the oil pick-up pipe to the
cylinder block. The baffle can then be
manipulated over the oil pick-up pipe. On C
16 NZ2, 1.8 and 2.0 litre models, prise the
rubber gasket from the sump baffle.
10If need be, the oil pick-up pipe can be
removed by unscrewing the single bolt
securing the support bracket to the cylinder
block (if not already done). Then remove the
two bolts securing the end of the pipe to the
oil pump. Recover the O-ring.
11Clean all traces of old gasket and sealing
compound from the mating faces of the
cylinder block, sump baffle (where
applicable), and sump.
Refitting
12Begin refitting by applying sealing
compound (Vauxhall part No 90485251 or
equivalent) to the joints between the oil pump
and cylinder block, and the rear main bearing
cap and cylinder block (see illustrations).
13On C 16 NZ2, 1.8 and 2.0 litre locate a
new rubber gasket over the sump baffle
flange, ensuring that it is seated correctly (see
illustration).
14On 1.6, 1.8 and 2.0 litre models, offer the
sump baffle up to the cylinder block,
manipulating it over the oil pick-up pipe where
applicable.
15If the oil pick-up pipe has been removed,
refit it to the oil pump using a new O-ring and
tighten bolts to the specified torque (see
illustrations).
16Where applicable, refit the bracket
securing the oil pick-up pipe to the cylinder
block, ensuring that it passes through the
relevant hole in the sump baffle, if applicable
(see illustration).
17Coat the sump securing bolts with
thread-locking compound (i.e. Vauxhall part
No. 90167347), then refit the sump, and
tighten the bolts to the specified torque (see
illustrations).
SOHC engine procedures 2A•27
29.12B Applying sealing compound to the
joint between the oil pump and cylinder
block - 2.0 litre engine
29.15B . . .and tighten the securing bolts
to the specified torque - 2.0 litre engine29.15A Fit a new O-ring to the oil pick-up
pipe . . .29.13 Locate a new rubber gasket over
the sump baffle flange - 2.0 litre engine
29.12A Apply sealing compound (arrowed)
to oil pump and rear main bearing cap
joints before refitting sump
28.4 Fitting a new crankshaft rear oil seal -
2.0 litre engine
2A
Inspection
3Check the clearance between the inner and
outer gear teeth (backlash) using a feeler
blade (see illustration).
4Check the clearance between the edges of
the gears and the housing (endfloat) using a
straight edge and a feeler blade (see
illustration).
5If any of the clearances are outside the
specified limits, renew the components as
necessary.
6Ensure that the gears and the interior of the
pump body are scrupulously clean before
reassembly, and note that the outer gear is
marked with a punch dot to indicate the gear
outer face.
7The oil pressure relief valve components
can be removed from the pump by
unscrewing the cap (see illustration).
Examine the spring and plunger, and renew if
necessary.
Reassembly
8Thoroughly clean the components before
refitting.
9Always renew the crankshaft front oil seal at
the front of the oil pump housing. Prise out the
old seal using a screwdriver, and fit the new
seal using a socket or tube, so that it is flush
with the outer face of the housing (see
illustrations).
10Ensure that the mating faces of the rear
cover and the pump housing are clean, then
coat the pump housing mating face with
sealing compound (Vauxhall part No
90485251, or equivalent) and refit the rear
cover. Refit and tighten the securing screws.
11Refit the pump, as described in Section 30.
32Pistons and connecting rods
- removal and refitting
4
Note: New big-end cap bolts must be used on
refitting
Removal
1Remove the cylinder head, as described
previously in Section 20.
2Remove the sump, oil pick-up pipe and
sump baffle (where applicable), as described
in Section 29.3If the connecting rods and big-end caps are
not marked to indicate their positions in the
cylinder block (i.e. cylinder numbers),
centre-punch them at adjacent points either
side of the cap/rod joint. Note to which side of
the engine the marks face (see illustration).
4Unscrew the big-end cap bolts from the
first connecting rod, and remove the cap. If
the bearing shells are to be re-used, tape the
cap and shell together.
5Check the top of the piston bore for a wear
ridge. If evident, carefully scrape it away with
a ridge reaming tool, otherwise as the piston
is pushed out of the block, the piston rings
may jam against the ridge.
6Place the wooden handle of a hammer
against the bottom of the connecting rod, and
push the piston/rod assembly up and out of the
cylinder bore. Recover the bearing shell, and
tape it to the connecting rod if it is to be re-used.
7Remove the remaining three assemblies in
a similar way. Rotate the crankshaft as
necessary to bring the big-end bolts to the
most accessible position.
8The piston can be separated from the
connecting rod by removing the circlips that
secure the fully floating gudgeon pin. Note the
orientation of the piston and connecting rod
before separation, and if necessary, make
alignment marks. Reassembly is a reversal of
dismantling ensuring that the piston and
connecting rod are correctly orientated.
9The pistons and connecting rods can be
examined for wear and damage, as described
in Section 33, and the bearings can be
examined as described in Section 35.
Refitting
10Begin reassembly by laying the
piston/connecting rod assemblies out in their
correct order, complete with bearing shells,
ready for refitting into their respective bores in
the cylinder block.
11Ensure that the seats for the bearing
shells are absolutely clean, and then fit the
shells into the seats.
12Wipe out the cylinder bores and oil them.
Oil the piston rings liberally, and ensure that
the ring gaps are positioned as described in
Section 33.
13Fit a piston ring compressor tool to the
first assembly to be installed.
SOHC engine procedures 2A•29
31.7 Oil pressure relief valve components
- 2.0 litre SOHC engine
32.3 Big-end cap centre punch
identification marks (circled). Note that lug
on bearing cap faces flywheel end of
engine - 2.0 litre SOHC engine
31.9B . . .and fit the new seal using a
socket - 2.0 litre SOHC engine31.9A Prise out the old crankshaft front
oil seal . . .
31.4 . . .and between the edges of the
gears and the housing -
2.0 litre SOHC engine31.3 Check the clearance between the
inner and outer gear teeth . . .
2A
14Insert the rod and piston into the top of
the cylinder bore, so that the base of the
compressor stands on the block. Check that
the connecting rod markings are towards the
side of the engine noted during removal. Note
that the arrow or notch, as applicable, on the
piston crown should point towards the timing
belt end of the engine, and the lugs on the
connecting rods should point towards the
flywheel end of the engine (see illustrations).
15Apply the wooden handle of a hammer to
the piston crown and tap the assembly into
the bore, at the same time releasing the
compressor (see illustration).
16Oil the relevant crankpin, then guide the
big-end of the connecting rod near to the
crankpin, and pull it firmly onto the crankpin.
Ensure that the bearing shell remains in
position in the connecting rod.
17Fit the big-end cap, with the markings
towards the side of the engine noted during
removal (see illustration). Note that the lug
should point towards the flywheel end of the
engine.
18Fit new big-end cap bolts, and tighten
them to the specified torque in the two stages
given in the Specifications (see illustrations).
19Repeat the procedure on the remaining
three assemblies.
20Refit the sump baffle (where applicable),
oil pick-up pipe and sump, as described in
Section 29.
21Refit the cylinder head, as described
previously in this Section 20.
33Pistons and connecting rods
-examination and renovation
4
Examination
1Examine the mating faces of the big-end
caps to see if they have ever been filed, in a
mistaken attempt to take up bearing wear.
This is extremely unlikely, but if evident, the
offending connecting rods and caps must be
renewed.
2Check the alignment of the rods visually,
and if all is not well, take the rods to a
Vauxhall dealer for a more detailed check.
3The gudgeon pins are an interference
(shrink) fit in the connecting rod small ends.
Separation of the pistons and rods is a job for
a dealer due to the special tools required, asis any remedial action required if the gudgeon
pin is no longer an interference fit in the rod.
4Examine the pistons for ovality, scoring and
scratches.
5If new rings are to be fitted to the existing
pistons, expand the old rings over the tops of
the pistons. The use of two or three old feeler
blades will be helpful in preventing the rings
dropping into empty grooves. Note that the oil
control ring is in three sections, and note
which way up each ring is fitted, for use when
refitting (see illustrations).
Renovation
6Before fitting the new rings to the pistons,
insert them into their relevant cylinder bores,
and check that the ring end gaps are within the
specified limits using a feeler blade (see
illustration). Check the ring gaps at the upper
and lower limits of the piston travel in the bores.
2A•30SOHC engine procedures
32.14A Piston crown arrow must point
towards timing belt end of engine -
1.6 litre engine32.14C Lugs (arrowed) on connecting rod
and big-end cap must point towards
flywheel end of engine - 1.6 litre engine
33.5A Using a feeler blade to aid removal
of a piston ring - 2.0 litre SOHC engine32.18B . . .then through the specified
angle - 2.0 litre SOHC engine32.18A Tighten the big-end cap bolts to
the specified torque . . .
32.17 Fitting a big-end bearing cap -
2.0 litre SOHC engine32.15 Tapping a piston into its bore -
2.0 litre SOHC engine
32.14B . . .and similarly for the 2.0 litre
SOHC engine
7If any of the ring end gaps exceed the
specified tolerance, the relevant rings will have
to be renewed, and if the ring grooves in the
pistons are worn, new pistons may be required.
8Clean out the piston ring grooves using a
piece of old piston ring as a scraper. Take
care not to scratch the surface of the pistons.
Protect your fingers, piston ring edges are
sharp. Also probe the groove oil return holes,
to ensure that they are not blocked.
9Check the cylinder bores for signs of wear
ridges towards the top of the bores. If wear
ridges are evident, and new piston rings are
being fitted, the top ring must be stepped to
clear the wear ridge, or the bore must be
de-ridged using a scraper.
10Fit the oil control ring sections with the
lower steel ring gap offset 25 to 50 mm to the
right of the spreader ring gap, and the upper
steel ring gap offset by the same distance to
the left of the spreader ring gap.
11Fit the lower compression ring, noting that
the ring is tapered or stepped. The ring should
be fitted with the word “TOP” uppermost.
12Fit the upper compression ring, and offset
the ring gap by 180°to the lower compression
ring gap. If a stepped ring is being fitted, fit
the ring with the smaller diameter of the step
uppermost.
13If new pistons are to be fitted, they must
be selected from the grades available, after
measuring the cylinder bores as described in
Section 36.
14Normally the appropriate oversize pistons
are supplied by the dealer when the block is
rebored.15Whenever new piston rings are being
installed, the glaze on the original cylinder
bores should be “broken”, using either
abrasive paper or a glaze-removing tool in an
electric drill. If abrasive paper is used, use
strokes at 60°to the bore centre line, to create
a cross-hatching effect.
34Crankshaft and bearings -
removal and refitting
4
Note: New main bearing cap bolts must be
used on refitting
Removal
1With the engine removed from the vehicle,
continue as follows.
2Remove the cylinder head, as described
previously in Section 20.
3Remove the sump, oil pick-up pipe and
sump baffle (where applicable), as described
in Section 29.
4Remove the oil pump, as described in
Section 30.
5Remove the flywheel or flexplate (if
applicable), as described in Sections 25 and
26.
6Remove the pistons and connecting rods,
as described in Section 32.
7Invert the engine so that it is standing on
the top face of the cylinder block.
8The main bearing caps are numbered 1 to 4
from the timing belt end of the engine. The
rear (flywheel end) cap is not marked. Toensure that the caps are refitted the correct
way round, note that the numbers are read
from the coolant pump side of the engine with
the engine inverted (see illustration).
9Unscrew and remove the main bearing cap
bolts, and tap off the bearing caps. If the
bearing shells are to be re-used, tape them to
their respective caps.
10Note that the centre bearing shell
incorporates thrust flanges to control
crankshaft endfloat.
11Lift the crankshaft (complete with timing
sensor wheel, if fitted), from the crankcase.
12Extract the upper bearing shells, and
identify them for position if they are to be
re-used.
13The crankshaft, bearings and sensor
wheel can be examined for wear and damage,
as described in Section 35, and the cylinder
block and bores can be examined as
described in Section 36.
Refitting
14Begin refitting by ensuring that the
crankcase and crankshaft are thoroughly
clean, and that all oilways are clear. If
possible, blow through the oil drillings with
compressed air, and inject clean engine oil
into them.
15If the crankshaft is being replaced, where
applicable, transfer the timing sensor wheel
and tighten to correct torque.
16Wipe clean the bearing shell seats in the
crankcase and the bearing caps, then fit the
upper bearing shells to their seats.
17Note that there is a tag on the back of
each bearing shell, which engages with a
groove in the relevant seat in the crankcase or
bearing cap (see illustration).
18If new bearing shells are being fitted, wipe
away all traces of protective grease.
SOHC engine procedures 2A•31
33.6 Measuring a piston ring end gap
using a feeler blade34.8 Main bearing cap identification mark
(arrowed) - 1.6 litre engine34.17 Main bearing shell tag (arrowed)
engages with groove in cylinder block -
2.0 litre SOHC engine
33.5C Sectional view showing correct
orientation of piston rings - all engines33.5B Removing the centre section of the
oil control ring - 2.0 litre SOHC engine
2A
A good alternative to
compressed air, is to use a
water dispersing lubricant
spray into each hole, using
the spout provided.
31Refit the previously removed
components, referring to the relevant
Sections of this Chapter.
35Crankshaft and bearings -
examination
4
Examination
1Examine the crankpin and main journal
surfaces for signs of scoring or scratches, and
check the ovality and taper of the crankpins
and main journals. If the bearing surface
dimensions do not fall within the tolerance
ranges given in the Specifications at the
beginning of this Chapter, the crankpins
and/or main journals will have to be reground.
2Big-end and crankpin wear is accompanied
by distinct metallic knocking, particularly
noticeable when the engine is pulling from low
revs, and some loss of oil pressure.
3Main bearing and main journal wear is
accompanied by severe engine vibration rumble
- getting progressively worse as engine rev’s
increase - and again by loss of oil pressure.
4If the crankshaft requires regrinding, take it
to an engine reconditioning specialist, who
will machine it for you and supply the correct
undersize bearing shells.
5Inspect the big-end and main bearing shells
for signs of general wear, scoring, pitting and
scratches. The bearings should be matt grey
in colour. With leadindium bearings, should a
trace of copper colour be noticed, the
bearings are badly worn, as the lead bearing
material has worn away to expose the indium
underlay. Renew the bearings if they are in
this condition, or if there are any signs of
scoring or pitting. You are strongly advised
to renew the bearings - regardless of their
condition at time of major overhaul.
Refitting used bearings is a false economy.
6The undersizes available are designed to
correspond with crankshaft regrind sizes. Thebearings are in fact, slightly more than the
stated undersize, as running clearances have
been allowed for during their manufacture.
7Main and big-end bearing shells can be
identified as to size by the marking on the
back of the shell. Standard size shell bearings
are marked STD or .00, undersize shells are
marked with the undersize such as 0.020 u/s.
This marking method applies only to
replacement bearing shells, and not to those
used during production.
8An accurate method of determining bearing
wear is by using a Plastigage. The crankshaft
is located in the main bearings (and, if
necessary, the big-end bearings), and the
Plastigage filament is located across the
journal. Vauxhall recommend that the
crankshaft journal and bearing shells are
lightly lubricated, to prevent the Plastigage
from tearing as the bearing cap is removed.
The bearing cap should be fitted, and the
bolts tightened to the specified torque. The
cap is then removed, and the width of the
filament is checked against a scale that shows
the bearing running clearance. The clearance
should be compared with that given in the
Specifications.
9Where applicable, check the teeth of the
crankshaft TDC sensor wheel for damage
(see illustration). If evident, the crankshaft
must be renewed.
10Similarly, check the condition of the pins
in the front crankshaft balance weight, which
serve as detect points for the plug-in
diagnostic sensor used by Vauxhall dealers
(see illustration).
36Cylinder block and bores -
examination and renovation
4
Examination
1Examine the cylinder bores for taper,
ovality, scoring and scratches. Start bycarefully examining the top of the cylinder
bores. If they are at all worn, a very slight
ridge will be found on the thrust side. This
marks the top of the piston ring travel. The
owner will have a good indication of the bore
wear before dismantling the engine, or
removing the cylinder head. Excessive oil
consumption, accompanied by blue smoke
from the exhaust, is a sure sign of worn
cylinder bores and piston rings.
2Measure the bore diameter across the
block, and just below any ridge. This can be
done with an internal micrometer or a dial
gauge. Compare this with the diameter of the
bottom of the bore, which is not subject to
wear. If no measuring instruments are
available, use a piston from which the rings
have been removed, and measure the gap
between it and the cylinder wall with a feeler
blade. Refer to the Specifications. If the
cylinder wear exceeds the permitted
tolerances, then the cylinders will need
reboring, in which case note the following
points:
a)Piston and cylinder bores are closely
matched in production. The actual
diameter of the piston is indicated by
numbers on its crown; the same numbers
stamped on the crankcase indicate the
bore diameter
b)After reboring has taken place, the
cylinder bores should be measured
accurately and oversize pistons selected
from the grades available to give the
specified piston-to-bore clearance
c)For grading purposes, the piston diameter
is measured across the bottom of the skirt
3If the wear is marginal and within the
tolerances given, new special piston rings can
be fitted to offset the wear.
4Thoroughly examine the crankcase and
cylinder block for cracks and damage, and
use a piece of wire to probe all oilways and
waterways to ensure that they are
unobstructed.
SOHC engine procedures 2A•33
35.10 Check the condition of the pins (arrowed) in the front
crankshaft balance weight - 2.0 litre SOHC engine35.9 Check the condition of the TDC sensor wheel teeth at the
front of the crankshaft - 2.0 litre SOHC engine
2A