coolant FORD SIERRA 1991 2.G SOHC Engines Workshop Manual

The following operations can be carried out
without removing the engine from the vehicle:
a)Removal and servicing of the cylinder
head
b)Removal of the camshaft after removal of
the cylinder head
c)Removal of the timing belt and sprockets
d)Removal of the sump
e)Removal of the oil pump
f)Removal of the pistons and connecting
rods
g)Removal of the big-end bearings
h)Removal of the engine mountings
i)Removal of the clutch and flywheel
j)Removal of crankshaft front and rear oil
seals
k)Removal of the auxiliary shaft
The following operations can only be carried
out after removing the engine from the
vehicle:
a)Removal of the crankshaft main bearings
b)Removal of the crankshaft
The engine may be lifted out either on its
own, or together with the manual
gearbox/automatic transmission. Unless work
is to be carried out on the manual
gearbox/automatic transmission, it is
recommended that the engine is removed on
its own. Where automatic transmission is
fitted, the engine should where possible be
removed on its own due to the additional
weight of the transmission. Note: The air conditioning system should
always be discharged by a Ford dealer or air
conditioning specialist.
Note: Refer to the warning in Section 8 before
proceeding. A suitable hoist and lifting tackle
will be required for this operation.
1Disconnect the battery negative lead.
2Remove the bonnet.
3On carburettor models remove the air cleaner.
4On fuel injection models, disconnect the
crankcase ventilation hose from the air inlet
hose, then disconnect the air inlet hose from
the throttle body. Depress the locking clip on
the airflow meter wiring plug and disconnect
the plug (pulling on the plug, not the wiring)
then release the four securing clips and lift off
the air cleaner lid with the airflow meter and
air inlet hose.
5Remove the four retaining clips and
unscrew the two retaining screws, then
withdraw the upper section of the cooling fan
shroud from the radiator. Unclip and remove
the lower section of the shroud.
6Remove the thermo-viscous cooling fan as
described in Chapter 3.
7Drain the cooling system.
8Disconnect the upper radiator hose and
where applicable, the expansion tank hose
from the thermostat housing.
9Disconnect the coolant hoses from the
coolant pump, and where applicable from the
inlet manifold and automatic choke. Unclip
the coolant hose from the bracket on the
exhaust manifold hot air shroud/heat shield,
or the camshaft cover, as applicable.
10On carburettor models, where applicable
disconnect the vacuum pipe from the engine
management module.
11Disconnect the brake servo vacuum pipe
from the inlet manifold.
12On carburettor models, disconnect the fuel
hoses from the carburettor and where
applicable the mechanical fuel pump and plug
the ends of the hoses to minimise petrol
spillage. Remember to take adequate fire
precautions.
13On fuel injection models, disconnect the
fuel feed line from the fuel pressure regulator,
then disconnect the fuel supply hose from thefuel rail. Position a suitable container beneath
the pressure regulator, then slowly loosen the
fuel feed union to relieve the pressure in the
fuel lines before disconnecting the union.
Take adequate fire precautions. Plug the ends
of the hoses to minimise petrol spillage.
14Disconnect the throttle cable, and where
applicable remove its bracket.
15Disconnect the HT lead from the ignition
coil.
16Disconnect the wiring from the following
components as applicable depending on
model:
Alternator
Starter motor
Distributor
Oil pressure warning lamp switch
Temperature gauge sender
Engine coolant temperature sensor
Automatic choke
Automatic choke pull-down solenoid
Carburettor anti-dieselling valve
Inlet manifold heater
Carburettor stepper motor
Fuel injection harness
Dipstick
17Where applicable, detach the power
steering pump from the cylinder block and
move it to one side.
18Unscrew and remove the top engine-to-
gearbox bolts which are accessible from the
engine compartment. Note the location of the
earth strap on one of the bolts.
19Note the location of the earth strap on the
rear inlet manifold stud, then remove the nut
and disconnect the strap.
20Apply the handbrake (if not already done),
jack up the front of the vehicle and support on
axle stands (see ÒJacking and Vehicle SupportÓ).
21Drain the engine oil into a suitable
container.
22Remove the starter motor.
23Remove the exhaust downpipe.
24Unscrew the nuts or bolts, as applicable,
securing the engine mountings to the
crossmember. Recover the washers.
25Unscrew and remove the remaining
engine-to-gearbox bolts, and remove the bolt
from the engine adapter plate (see
illustration).
26Remove the two securing bolts and
disconnect the engine-to-gearbox brace from
the engine and gearbox.
27Working inside the vehicle, place a
wooden block under the clutch pedal to raise
it fully against its stop which will hold the
automatic adjuster pawl clear of the toothed
quadrant.
28Disconnect the clutch cable from the
clutch release arm, and pass the cable
through the bellhousing. Where applicable,
remove the clip securing the clutch cable to
the right-hand engine mounting bracket. Note
the cable routing for use when refitting.
29Lower the vehicle to the ground, and
support the gearbox with a trolley jack, using
a block of wood between the jack and the
gearbox to spread the load.
30Make a final check to ensure that all
relevant wires, pipes and hoses have been
disconnected to facilitate engine removal.
9Engine - removal leaving
manual gearbox in vehicle
8Method of engine removal
7Major operations requiring
engine removal
6Major operations possible with
the engine in the vehicle
2A¥8SOHC engines
9.25 Engine adapter plate bolt (A) and
engine-to-gearbox brace (B)
Warning: Vehicles equipped
with air conditioning:
Components of the air
conditioning system may
obstruct work being undertaken on the
engine, and it is not always possible to
unbolt and move them aside sufficiently,
within the limits of their flexible
connecting pipes. In such a case, the
system should be discharged by a Ford
dealer or air conditioning specialist. The
refrigerant is harmless under normal
conditions, but in the presence of a naked
flame (or a lighted cigarette) it forms a
highly toxic gas. Liquid refrigerant spilled
on the skin will cause frostbite. If
refrigerant enters the eyes, rinse them
with a diluted solution of boric acid and
seek medical advice immediately.

4Check that the engine adapter plate is
correctly positioned on its locating dowels.
5Refit the propeller shaft.
6Refit the exhaust system.
7Reconnect the clutch cable to the release
arm, ensuring that it is routed as noted during
removal.
8Fill the engine with the correct grade and
quantity of oil.
9Fill the cooling system.
10Check and if necessary top-up the
gearbox oil level.
11Check and if necessary adjust the tension
of the alternator and where applicable the
power steering pump drivebelt(s).
12Adjust the throttle cable.
1Reverse the removal procedure described
in Section 12, noting the following points.
2Check that the engine adapter plate is
correctly positioned on its locating dowels.
3As the torque converter is only loosely
engaged in the transmission, care must be
taken to prevent the torque converter from
falling out forwards. When the torque
converter hub is fully engaged with the fluid
pump drivegear in the transmission, distance
ÒAÓ in illustration 2.24 of Chapter 7B must be
as shown. Incorrect installation of the torque
converter will result in damage to the
transmission.
4As the engine and transmission are
reconnected, guide the torque converter studs
through the holes in the driveplate, noting that
on the C3 type transmission, the torque
converter fluid drain plug must line up with the
opening in the driveplate (see illustration 2.25
in Chapter 7B). When the engine is positioned
flush with the engine adapter plate and the
transmission housing, check that the torque
converter is free to move axially a small
amount before refitting and tightening the
engine-to-transmission bolts.
5Do not tighten the torque converter-to-
driveplate nuts until the lower engine-to-
transmission bolts have been fitted and
tightened.
6Reconnect and adjust the selector rod.
7Refit the propeller shaft.8Refit the exhaust system.
9Fill the engine with the correct grade and
quantity of oil.
10Fill the cooling system.
11Check and if necessary top-up the
transmission fluid level.
12Check and if necessary adjust the tension
of the alternator and where applicable the
power steering pump drivebelt(s).
13Adjust the throttle cable.
14If applicable, adjust the kickdown cable.
1The engine mountings incorporate
hydraulic dampers and must be renewed if
excessive engine movement is evident.
2Working in the engine compartment,
unscrew the central nuts securing the engine
mounting brackets to the tops of the
mountings. Recover the washers where
applicable.
3Remove the two bolts or the central nut and
washer (as applicable) in each case securing
the mountings to the crossmember.
4Raise the engine using a hoist and lifting
tackle attached to the engine lifting brackets on
the cylinder head, or a jack with an interposed
block of wood under the sump, until the
mountings can be withdrawn (see illustration).
5Fit the new mountings, then lower the
engine onto them.
6Fit the bolts or the nuts and washers (as
applicable) securing the mountings to the
crossmember, and tighten them.
7Fit and tighten the central nuts, and washers
if applicable, securing the engine mounting
brackets to the tops of the mountings.
Dismantling
1It is best to mount the engine on a
dismantling stand but if this is not available,
stand the engine on a strong bench at a
comfortable working height. Failing this, it will
have to be stripped down on the floor.
2Cleanliness is most important, and if theengine is dirty, it should be cleaned with
paraffin while keeping it in an upright position.
3Avoid working with the engine directly on a
concrete floor, as grit presents a real source
of trouble.
4As parts are removed, clean them in a
paraffin bath. However, 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.
5It is advisable to have suitable containers
available to hold small items according to
their use, as this will help when reassembling
the engine and also prevent possible losses.
6Always obtain a complete set of new
gaskets for use during engine reassembly, but
retain the old gaskets with a view to using
them as a pattern to make a replacement if a
new one is not available.
7Where possible, refit securing nuts, bolts and
washers to their locations after removing the
relevant components. This will help to protect
the threads and will also prevent losses.
8Retain unserviceable components in order
to compare them with the new parts supplied.
9Suitable splined sockets will be required for
removal of the oil pump bolts, the timing belt
tensioner bolts on early models (up to mid-
1985), and the cylinder head bolts on early
models (up to early 1984) and a size T55 Torx
socket will be required to remove the cylinder
head bolts on later models (from early 1984).
10Before dismantling the main engine
components the following externally mounted
ancillary components can be removed, with
reference to the relevant Chapters of this
Manual and the relevant Sections of this
Chapter, where applicable:
Inlet manifold (and carburettor, where
applicable
Exhaust manifold
Fuel pump and operating pushrod (where
applicable)
Alternator
Distributor, HT leads and spark plug
Coolant pump, thermostat and housing
Temperature gauge sender and oil pressure
warning lamp switch
Oil filter
Dipstick
Engine mounting brackets (see illustration)
Crankcase ventilation valve and oil separator
Clutch
Alternator mounting bracket (see illustration)
18Engine dismantling,
examination, renovation and
reassembly - general information
17Engine mountings - renewal
16Engine/automatic
transmission assembly -
reconnection and refitting
SOHC engines 2A¥11
2A
18.10b Removing the alternator mounting
bracket18.10a Removing the right-hand engine
mounting bracket
17.4 Withdrawing an engine mounting

Examination and renovation
11With the engine completely stripped,
clean all the components and examine them
for wear. Each part should be checked, and
where necessary renewed or renovated as
described in the relevant Sections. Renew
main and big end shell bearings as a matter of
course, unless it is known that they have had
little wear and are in perfect condition.
12If in doubt as to whether to renew a
component which is still just serviceable,
consider the time and effort which will be
incurred should it fail at an early date.
Obviously the age and expected life of the
vehicle must influence the standards applied.
13Gaskets, oil seals and O-rings must all be
renewed as a matter of routine. Flywheel and
Torx type cylinder head bolts must be
renewed because of the high stresses to
which they are subjected.
14Take the opportunity to renew the engine
core plugs while they are easily accessible.
Knock out the old plugs with a hammer and
chisel or punch. Clean the plug seats, smear
the new plugs with sealant and tap them
squarely into position.
Reassembly
15To 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 must be
clear, and locking washers and spring
washers must be fitted where indicated. Oil all
bearings and other working surfaces
thoroughly with clean engine oil during
assembly.
16Before assembly begins, renew any bolts
or studs with damaged threads.
17Gather together a torque wrench, oil can,
clean rag, and a set of engine gaskets and oil
seals, together with a new oil filter.
18If they have been removed, new Torx type
cylinder head bolts and new flywheel bolts will
be required.
19After reassembling the main engine
components, refit the ancillary components
listed, referring to the appropriate Chapters
where necessary. Delicate items such as the
alternator and distributor may be left until after
the engine has been refitted if preferred.20If the crankcase ventilation oil separator
was removed, apply a liquid sealing agent to
its tube before pressing it into the cylinder
block.
Note: Refer to the warning in Section 8 before
proceeding. On models from mid-1985
(without a timing belt tensioner spring) the belt
tension should be checked using Ford special
tool No 21-113 after refitting. On models up to
mid-1985 (with a tensioner spring), a suitable
splined socket will be required for the
tensioner spring bolt. A suitable puller may be
required to remove the sprockets.
Removal
1If the engine is in the vehicle, carry out the
following operations:
a)Disconnect the battery negative lead
b)Remove the thermo-viscous cooling fan
c)Remove the coolant
pump/alternator/power-steering pump
drivebelt(s)
d)For improved access, remove the radiator
and disconnect the radiator top hose from
the thermostat housing
2Unscrew the three securing bolts and
washers and withdraw the timing cover. Note
the position of the fourth bolt above the
crankshaft pulley which can be left in place.
3Using a socket on the crankshaft pulley
bolt, turn the engine clockwise until the TDC
(top dead centre) mark on the crankshaft
pulley is aligned with the pointer on the
crankshaft front oil seal housing (see
illustration 16.2a of Chapter 5) and the pointer
on the camshaft sprocket backplate is aligned
with the indentation on the cylinder head (see
illustration).
4On models up to mid-1985 (with a tensioner
spring), loosen the timing belt tensioner spring
bolt using the special splined socket (see
illustration), then loosen the tensioner pivot
bolt. If necessary for improved access,
remove the thermostat housing. Press the
tensioner against the spring tension and
tighten the pivot bolt to retain the tensioner in
the released position.5On models from mid-1985 (without a
tensioner spring), loosen the timing belt
tensioner bolts (see illustration)and move
the tensioner away from the belt. If necessary
to improve access, remove the thermostat
housing.
6Mark the running direction of the belt if it is
to be re-used, then slip it off the camshaft
sprocket.
7Slacken the crankshaft pulley bolt. Prevent
the crankshaft from turning by engaging top
gear (manual gearbox only) and having an
assistant apply the brake pedal hard, or by
removing the starter motor and jamming the
ring gear teeth with a lever. Alternatively, if the
pulley has peripheral bolt holes, screw in a
couple of bolts and use a lever between them
to jam it. Do not allow the crankshaft to turn
very far, or piston/valve contact may occur.
8Remove the bolt and washer and withdraw
the pulley. If the pulley will not come off easily,
refit the bolt part way and use a puller (see
illustration). A puller will almost certainly be
required on fuel-injection models.
9Remove the guide washer from in front of
the crankshaft sprocket, then remove the
timing belt (see illustration). Do not kink it or
get oil on it if it is to be re-used.
10If desired, the sprocket can be removed as
follows, otherwise proceed to paragraph 21.
11Remove the crankshaft sprocket, refitting
the bolt part way and using a puller if
necessary (see illustration).
12Unscrew the auxiliary shaft sprocket bolt
while holding the sprocket stationary with a
screwdriver inserted through one of the holes.
19Timing belt and sprockets -
removal and refitting
2A¥12SOHC engines
19.3 TDC pointer on camshaft sprocket
backplate aligned with indentation on
cylinder head19.5 Timing belt tensioner bolts (arrowed) -
models from mid-1985
19.8 Using a puller to remove a pressed
type crankshaft pulley
19.4 Loosening the timing belt tensioner
spring bolt using a splined socket - models
up to mid-1985

anti-clockwise (No 1 cylinder at 60¼ BTDC)
(see illustration).
29The belt tension should now be checked
by applying Ford tension gauge, tool No 21-
113 to the longest belt run. Desired gauge
readings are:
Used belt - 4 to 5
New belt - 10 to 11
If the tension gauge is not available, a rough
guide is that the belt tension is correct when
the belt can be twisted 90¼ in the middle of the
longest run with the fingers, using moderate
pressure (see illustration). In this case, the
vehicle should be taken to a Ford dealer so
that the belt tension can be checked using the
special gauge at the earliest opportunity.
30If adjustment of belt tension is necessary,
turn the crankshaft clockwise to bring No 1
cylinder to TDC, then slacken the tensionerbolts and move the tensioner to increase or
decrease the belt tension. Tighten the
tensioner bolts to the specified torque.
31Turn the crankshaft 90¼ clockwise past
TDC, then anti-clockwise back to the 60¼
BTDC position (No 1 cylinder at 60¼ BTDC).
Check the belt tension again.
32Repeat the procedure given in paragraphs
30 and 31 until the belt tension is correct.
33Tighten the crankshaft pulley bolt to the
specified torque, preventing the crankshaft
from turning as described in paragraph 7 (see
illustration).
34Refit the timing cover and tighten its bolts.
35If the engine is in the vehicle, reverse the
operations described in paragraph 1.
36When the engine is next started, check
the ignition timing is correct.Note: Refer to the warning in Section 8 and
the note at the beginning of Section 21 before
proceeding.
Removal
1Disconnect the battery negative lead.
2Drain the cooling system.
3Disconnect the coolant hose from the
thermostat housing.
4Disconnect the wiring from the temperature
gauge sender.
5Disconnect the HT leads from the spark
plugs and from the clips on the camshaft
cover and remove the spark plugs.
6On carburettor models, remove the air
cleaner.
7The cylinder head can be removed either
with or without the manifolds. If desired, the
inlet manifold can be unbolted and moved to
one side, leaving the wires, hoses, pipes and
cables connected, but care must be taken not
to strain any of the wires, hoses, pipes or
cables.
8Unscrew the three securing nuts and
disconnect the exhaust downpipe from the
manifold flange. Recover the gasket.
9Disconnect the coolant hose from the clip
on the exhaust manifold hot air shroud, and if
desired, remove the exhaust manifold.
10If the inlet manifold is to be removed with
the cylinder head, disconnect all relevant
20Cylinder head - removal and
refitting (engine in vehicle)
2A¥14SOHC engines
19.33 Holding a pressed type crankshaft
pulley with two bolts and a lever while
tightening the bolt19.29 Twisting the timing belt to assess its
tension
19.28 Timing belt tension checking sequence - models from mid-1985
A No 1 cylinder at TDCB No 1 cylinder at 60¡BTDC for
checkingC Return No 1 cylinder to TDC for
adjustment

wires, hoses, pipes and cables, otherwise,
unbolt the manifold and move it to one side,
ensuring that it is adequately supported.
11If not already done, unclip any wires and
hoses from the camshaft cover, noting their
locations for use when refitting, and on fuel
injection models unbolt the bracing strut
securing the inlet manifold to the right-hand
side of the cylinder head.
12If desired, remove the thermostat and
housing, and the temperature gauge sender.
13Proceed as described in Section 21 for
cylinder head removal.
Refitting
14With the cylinder head refitted as
described in Section 21, proceed as follows.
15Where applicable, refit the temperature
gauge sender and the thermostat and
housing.
16Refit the manifolds and/or reconnect all
wires, hoses, pipes and cables, as applicable.
17Reconnect the exhaust downpipe to the
manifold, using a new gasket.
18Refit the coolant hose to the clip on the
exhaust manifold hot air shroud.
19Refit the spark plugs and reconnect the
HT leads.
20Reconnect the temperature gauge sender
wiring.
21Reconnect the coolant hoses to the
thermostat housing.
22Fill the cooling system.
23If not already done, refit any hoses and
wires to the camshaft cover, as noted during
removal, and on fuel injection models refit the
inlet manifold bracing strut. If splined type
cylinder head bolts have been used, leave
these operations until the bolts have been
finally tightened after running the engine.
24Refit the air cleaner on carburettor
models.
25Reconnect the battery negative lead.
26If splined type cylinder head bolts have
been used, start the engine and run it at 1000
rpm for 15 minutes, then stop the engine,
remove the air cleaner and the camshaft cover
as described previously, and finally tighten the
cylinder head bolts to the fourth stage (see
Specifications). Refit the camshaft cover on
completion, then refit any hoses and wires,
and on fuel injection models the inlet manifold
bracing strut. Refit the air cleaner.Note: Up to early 1984, splined type cylinder
head bolts were used, and from early 1984,
size T55 Torx bolts were used. Torx type bolts
must always be renewed after slackening. The
two types of bolts are interchangeable, but
only in complete sets - the two types must not
be mixed on the same engine. A suitable
special socket will be required for removal of
the bolts, and a new cylinder head gasket
must be used when refitting.
Removal
1With the manifolds removed, proceed as
follows.
2Remove the timing belt.
3Where applicable, disconnect the breather
hose from the camshaft cover.
4Unscrew the ten securing bolts and remove
the camshaft cover and gasket. Take care not
to lose the spacer plates which fit under the
bolt heads, where applicable.
5Using the relevant special socket, unscrew
the ten cylinder head bolts half a turn at a time
in the reverse order to that shown for
tightening.
6With the bolts removed, lift the cylinder
head from the block. If the cylinder head is
stuck, tap it free with a wooden mallet. Place
the cylinder head on blocks of wood to
prevent damage to the valves.
7Recover the gasket.
Refitting
8Commence refitting as follows.
9With the cylinder head supported on blocks
of wood, check and if necessary adjust thevalve clearances. This work is easier to carry
out on the bench rather than in the vehicle.
10Turn the crankshaft so that No 1 piston is
approximately 20 mm (0.8 in) before TDC.
This precaution will prevent any damage to
open valves.
11Make sure that the mating faces of the
cylinder block and cylinder head are perfectly
clean, then locate the new gasket on the
block making sure that all the internal holes
are aligned (see illustration). Do not use
jointing compound.
12Turn the camshaft so that the TDC pointer
on the camshaft sprocket backplate is aligned
with the indentation on the front of the
cylinder head.
13Lower the cylinder head onto the gasket.
The help of an assistant will ensure that the
gasket is not dislodged.
14Lightly oil the cylinder head bolt threads
and heads, then insert the bolts into their
locations in the cylinder head. Note that if the
original bolts were of the Torx type, new bolts
must be used when refitting.
15Using the relevant special socket, tighten
the bolts in the correct sequence (see
illustration)to the stages given in the
Specifications. Note that the bolt tightening
stages are different for splined and Torx type
bolts. If splined type bolts are used, they must
be finally tightened to the fourth stage after
the engine has been run for 15 minutes (see
Specifications).
16Check the condition of the camshaft
cover gasket and renew if necessary. Fit the
gasket to the camshaft cover, ensuring that
the locating tabs and dovetails are correctly
located, then refit the camshaft cover and
tighten the securing bolts in the order shown
(see Chapter 1, Section 23), ensuring that the
spacer plates are in position under the bolt
heads, where applicable.
17Where applicable, reconnect the breather
hose to the camshaft cover.
18Refit the timing belt.
21Cylinder head - removal and
refitting (engine removed)
SOHC engines 2A¥15
2A
21.15 Cylinder head bolt tightening sequence
21.11 Fitting a new cylinder head gasket
Tap a stuck cylinder head
free with a wooden mallet.
Do not insert a lever into the
head joint as this may
damage the mating faces.

components, but there must be no tight spots
or binding.
28Check that the crankshaft endfloat is
within the specified limits by inserting a feeler
blade between the centre crankshaft web and
the thrustwashers.
29Make sure that the rear oil seal is fully
located onto its seating. Coat the rear main
bearing cap sealing wedges with sealing
compound, then press them into position
using a blunt screwdriver with the rounded
red face towards the cap (see illustration).
30Refit the oil pump and pick-up tube.
31Refit the crankshaft front oil seal housing
and the auxiliary shaft front cover using a new
gasket, and tighten the securing bolts. Smear
the lip of the oil seal with clean engine oil
before fitting; and using a straight edge, ensure
that the bottom face of the oil seal housing is
aligned with the bottom face of the cylinder
block before finally tightening the bolts.
32Refit the pistons and connecting rods.
33Refit the flywheel/driveplate and the
auxiliary shaft sprocket, crankshaft sprocket,
and timing belt.
1Examine the bearing surfaces of the
crankshaft for scratches or scoring and, using
a micrometer, check each journal and
crankpin for ovality. Where this is found to be
in excess of 0.0254 mm (0.001 in) the
crankshaft will have to be reground and
undersize bearings fitted.
2Crankshaft regrinding should be carried out
by a suitable engineering works, who will
normally supply the matching undersize main
and big-end shell bearings.
3Note that undersize bearings may already
have been fitted, either in production or by a
previous repairer. Check the markings on the
backs of the old bearing shells, and if in doubt
take them along when buying new ones.
Production undersizes are also indicated by
paint marks as follows:
White line on main bearing cap - parent bore
0.40 mm oversize
Green line on crankshaft front counterweight
- main bearing journals 0.25 mm
undersize
Green spot on counterweight - big-end
bearing journals 0.25 mm undersize4If the crankshaft endfloat is more than the
maximum specified amount, new
thrustwashers should be fitted to the centre
main bearings. These are usually supplied
together with the main and big-end bearings
on a reground crankshaft.
5An accurate method of determining bearing
wear is by the use of Plastigage. The
crankshaft is located in the main bearings
(and big-end bearings if necessary) and the
Plastigage filament located across the journal
which must be dry. The cap is then fitted and
the bolts/nuts tightened to the specified
torque. On removal of the cap the width of the
filaments is checked against a scale which
shows the bearing running clearance. This
clearance is then compared with that given in
the Specifications (see illustration).
6If the spigot bearing in the rear of the
crankshaft requires renewal, extract it with a
suitable puller. Alternatively fill it with heavy
grease and use a close fitting metal dowel
driven into the centre of the bearing. Drive the
new bearing into the crankshaft with a soft
metal drift.
1The cylinder bores must be examined for
taper, ovality, scoring and scratches. Start by
examining the top of the bores; if these are
worn, a slight ridge will be found which marks
the top of the piston ring travel. If the wear is
excessive, the engine will have had a high oil
consumption rate accompanied by blue
smoke from the exhaust.
2If available, use an inside dial gauge to
measure the bore diameter just below the
ridge and compare it with the diameter at the
bottom of the bore, which is not subject to
wear. If the difference is more than 0.152 mm
(0.006 in), the cylinders will normally require
reboring with new oversize pistons fitted.
3Proprietary oil control rings can be obtained
for fitting to the existing pistons if it is felt that
the degree of wear does not justify a rebore.
However, any improvement brought about by
such rings may be short-lived.
4If new pistons or piston rings are to be fitted
to old bores, deglaze the bores with abrasive
paper or a Òglaze busterÓ tool. The object is to
produce a light cross-hatch pattern to assistthe new rings to bed in.
5If there is a ridge at the top of the bore and
new piston rings are being fitted, either the
top piston ring must be stepped (Òridge
dodgerÓ pattern) or the ridge must be
removed with a ridge reamer. If the ridge is
left, the piston ring may hit it and break.
6Thoroughly examine the crankcase and
cylinder block for cracks and damage and use
a piece of wire to probe all oilways and
waterways to ensurethatthey are
unobstructed.
1Make a final check to ensure that
everything has been reconnected to the
engine and that no rags or tools have been left
in the engine bay.
2Check that oil and coolant levels are
correct.
3Start the engine. This may take a little
longer than usual as fuel is pumped up to the
engine.
4Check that the oil pressure light goes out
when the engine starts.
5Run the engine at a fast tickover and check
for leaks of oil, fuel or coolant. Also check
power steering and transmission fluid cooler
unions, where applicable. Some smoke and
odd smells may be experienced as assembly
lubricant burns off the exhaust manifold and
other components.
6Bring the engine to normal operating
temperature, then check the ignition timing
and the idle speed (where applicable) and
mixture.
7If splined type cylinder head bolts have
been used, stop the engine after it has been
running for 15 minutes, then remove the
crankshaft cover and tighten the cylinder
head bolts to the fourth stage given in the
Specifications, in the correct order.
8When the engine has completely cooled,
re-check the oil and coolant levels, and
check, and if necessary adjust, the valve
clearances.
9If new bearings, pistons etc have been
fitted, the engine should be run-in at reduced
speeds and loads for the first 500 miles (800
km) or so. It is beneficial to change the engine
oil and filter after this mileage.
37Initial start-up after overhaul or
major repair
36Cylinder block and bores -
examination and renovation35Crankshaft and bearings -
examination and renovation
2A¥24SOHC engines
34.24 Fitting a thrustwasher to the centre
main bearing cap35.5 Checking the width of the filament
against the scale of the packet34.29 Fitting a sealing wedge to the rear
main bearing cap