1983 FIAT UNO torque

2The big-end bearing shells can be renewed
without having to remove the cylinder head if
the caps are unbolted and the
piston/connecting rod pushed gently about
one inch up the bore (the crankpin being at its
lowest point). If these shells are worn,
however, the main bearing shells will almost
certainly be worn as well. In this case, the
engine should be removed for complete
overhaul including crankshaft removal.
3To remove the piston/connecting rods,
remove the cylinder head as described in
Section 29.
4Grip the oil pick-up pipe and twist or rock it
from its hole in the crankcase. It is an
interference fit in the hole.
5Unscrew the nuts from the big-end caps,
then remove the caps with their bearing
shells. The caps and their connecting rods are
numbered 1, 2, 3 and 4 from the timing cover
end of the engine. The numbers are adjacent
at the big-end cap joint and on the side of the
crankcase furthest from the auxiliary shaft.
6If the bearing shells are to be used again,
tape them to their respective big-end caps.
7Push each connecting rod/piston assembly
up the bore and out of the cylinder block.
There is one reservation; if a wear ridge has
developed at the top of the bores, remove this
by careful scraping before trying to remove
the piston/rod assemblies. The ridge will
otherwise prevent removal or break the piston
rings during the attempt.
8If the connecting rod bearing shells are to
be used again, tape the shells to their
respective rods.
9Dismantling the piston/connecting rod is
described in Section 18.
Refitting
10Fit the new shells into the connecting rod
and caps, ensuring the surfaces on which the
shells seat, are clean and dry.
11Check that the piston ring gaps are evenly
spaced at 120º intervals. Liberally oil the rings
and the cylinder bores.
12Fit a piston ring clamp to compress the
rings.
13Insert the piston/connecting rod into the
cylinder bore, checking that the rod assembly
is correct for that particular bore. The cap and
rod matching numbers must be furthest away
from the auxiliary shaft (Fig. 1.31).14Push the piston into the bore until the
piston ring clamp is against the cylinder block
and then tap the crown of the piston lightly to
push it out of the ring clamp and into the bore
(photo).
15Oil the crankshaft journal and fit the
big-end of the connecting rod to the journal.
Fit the big-end cap and nuts, checking that
the cap is the right way round (photo).
16Tighten the big-end nuts to the specified
torque. The correct torque is important as the
nuts have no locking arrangement. After
tightening each big-end, check the crankshaft
rotates smoothly (photo).
17Refit the oil pick-up pipe, the cylinder
head, oil pump and sump pan, all as
described earlier.
18Refill the engine with oil and coolant.
33 Engine mountings-
renewal
1
1Three engine/transmission flexible
mountings are used.
2To renew a mounting, support the weight of
the engine/transmission on a hoist or jack and
unbolt and remove the mounting.
3In the unlikely event of all three mountings
requiring renewal at the same time, only
disconnect them and renew them one at a
time.
34 Engine- method of removal
1The engine complete with transmission
should be removed by lowering it to the floor
and withdrawing it from under the front of the
car which will have been raised to provide
adequate clearance.
35 Engine/transmission-
removal and separation
3
1Open the bonnet, disconnect the
windscreen washer tube.
2Mark the hinge positions on the undersideof the bonnet and then with the help of an
assistant to support its weight unbolt and
remove the bonnet to a safe place.
3Disconnect the battery negative lead.
4Drain the cooling system and the engine
and transmission oils.
5Remove the air cleaner.
6From the rear of the alternator disconnect
the electrical leads.
7Disconnect the leads from the starter
motor, oil pressure and coolant temperature
switches, also the oil temperature switch.
8Disconnect the LT lead from the distributor
and the HT lead from the ignition coil.
9Disconnect the clutch cable from the
release lever at the transmission. Also
disconnect the speedometer drive cable
(knurled ring).
10Pull the leads from the reversing lamp
switch.
11Disconnect all coolant hoses from the
engine. Also disconnect the brake servo hose
from the intake manifold.
12Disconnect the choke and throttle
controls from the carburettor.
13Disconnect the inlet hose from the fuel
pump and plug the hose.
14Disconnect the fuel return hose from the
carburettor.
15Disconnect the coolant hoses from the
carburettor throttle block.
16Raise the front of the car and remove the
front roadwheels.
17Unscrew and remove the driveshaft to
hub nuts. These are very tight and a long
knuckle bar will be required when unscrewing
them. Have an assistant apply the brake pedal
hard to prevent the hub from turning.
18Working under the car, remove the inner
wing protective shields and then disconnect
the exhaust downpipe from the manifold.
19Disconnect the exhaust pipe sections by
removing the socket clamp just forward of the
rear axle beam. Remove the front section.
20Disconnect the forward ends of the
gearchange rods by prising their sockets from
the ballstuds.
21Unscrew the nuts on the steering tie-rod
end balljoints and then using a suitable
“splitter” tool, separate the balljoints from the
steering arms.
22Unbolt the front brake hose support clips
1116 cc and 1301 cc engine 1•27
32.16 Tightening a big-end cap nut32.15 Fitting a big-end cap32.14 Fitting piston into cylinder bore
1

42.9 Fitting the auxiliary shaft
41 Engine- reassembly (general)
Refer to Section 19, Part 2.
42 Engine-
complete reassembly
4
Crankshaft and main bearings
1Fit the bearing shells to their crankcase
seats and to their caps. The seatings and
backs of the shells must be spotlessly clean,
otherwise tight spots will occur when the
crankshaft is fitted. The centre bearing shell is
plain (photo).2Fit the thrust washer halves to their
locations at No. 5 bearing, noting that the oil
grooves in the washers face outwards (photo).
3Oil the surfaces of the bearing shells
liberally and lower the crankshaft into position
(photo).
4Fit the main bearing caps to their correct
locations, the correct way round (numerical
chisel marks towards the auxiliary shaft). The
rear cap is unmarked. Tighten the cap bolts to
the specified torque (photos).
5Check that the crankshaft rotates smoothly
and freely.
6At this stage, the crankshaft endfloat
should be checked. Prise the crankshaft fully
in one direction and measure the gap
between the machined face of the flywheel
mounting flange and the crankcase. Now
push the shaft in the opposite direction and
measure again. Ideally, a dial gauge should be
used for these measurements, but feelerblades will serve as a reasonable alternative.
The difference between the two dimensions
(feeler blades) or the total movement of the
crankshaft (dial gauge) should be within the
specified tolerance. If it is not, the thrust
washers at No. 5 main bearing will have to be
changed for thicker ones; this will require
taking out the crankshaft again to reach them.
7Fit new oil seals to the retainers and, using
new gaskets, bolt the retainers to the front
and rear ends of the crankshaft, having first
filled the oil seal lips with grease (photos).
Pistons/connecting rods
8The refitting operations are described in
Section 32.
Auxiliary shaft
9Lubricate the auxiliary shaft bearings and fit
the shaft into the crankcase (photo).
10Fit a new seal to the endplate and fit the
1•30 1116 cc and 1301 cc engine
42.7C Rear oil seal carrier42.7B Front oil seal carrier
42.7A Removing oil seal from carrier42.4B Tightening a main bearing cap bolt42.4A Number one main bearing cap
42.3 Lowering crankshaft into position42.2 Crankshaft thrust washers42.1 Main bearing shells

plate to the crankcase, using a new gasket
(photos).
11Fit the belt sprocket and partially tighten
its bolt. Then, using an oil filter strap wrench
or similar device to hold the sprocket against
rotation, tighten the bolt to the specified
torque. Take care not to damage the teeth of
the sprocket, which is of fibre construction
(photo).
Oil sump, sump pan and
breather
12Fit the oil drain pipe by tapping it into
place, squarely in its hole in the crankcase.
Tighten its retaining bolt (photo).
13Bolt up the oil pump, using a new gasket
at its mounting flange (photo).14Fit the sump (using a new gasket) and
tighten the securing screws to the specified
torque. Note the reinforcement washers
(photo).
15Insert the oil pump/driveshaft into the
distributor hole. This does not have to be
specially positioned as the distributor is
splined to the shaft and can be set by moving
its location in the splines (refer to Chapter 4)
(photo).
16Push the breather into its crankcase
recess and tighten its securing bolt (photos).Flywheel, crankshaft sprocket
and pulley
17Make sure that the flywheel-to-crankshaft
mounting flange surfaces are clean. Althoughthe bolt holes have unequal distances
between them, it is possible to fit the flywheel
in one of two alternative positions at 180º
difference. Therefore if the original flywheel is
being refitted, align the marks made before
removal.
18If a new flywheel is being fitted, or if
alignment marks were not made before
dismantling, set No. 1 position at TDC
(crankshaft front Woodruff key pointing
vertically). Fit the flywheel to its mounting
flange so that its timing dimple is uppermost
and in alignment with the relative position of
the TDC mark on the flywheel housing
inspection window.
19Insert the bolts and tighten them to the
specified torque, jamming the ring gear to
1116 cc and 1301 cc engine 1•31
42.11 Tightening camshaft sprocket bolt.
Note sprocket locking device42.10B Tightening auxiliary shaft end plate
bolt42.10A Auxiliary shaft end plate and
gasket
42.16B Crankcase breather and retaining
bolt42.16A Crankcase breather seal42.15 Fitting oil pump driveshaft
42.14 Tightening sump pan bolt42.13 Locating oil pump and gasket42.12 Tightening oil drain pipe bolt
1

prevent the flywheel turning. Fit the engine
endplate (photo).
20Fit the timing belt sprocket to the front
end of the crankshaft (photo).
21Fit the crankshaft pulley and the nut;
tighten it to the specified torque, again
jamming the starter ring gear to prevent the
crankshaft from rotating (photo).
Cylinder head
22Refitting is described in Section 29.
Camshaft carrier and camshaft
23Refitting is described in Section 27.
Timing belt and tensioner
24Refitting is described in Section 28, but
make sure that the belt cover rear plate is
bolted into position. If the engine mounting
bracket was removed, bolt it into positioncomplete with the tensioner plunger to
provide spring pressure to the belt pulley
(photos).
Valve clearances
25Check the valve clearances as described
in Section 26.
26Using new gaskets, bolt on the camshaft
carrier cover plate and the inlet and exhaust
manifolds using new gaskets. Fit the exhaust
manifold hot air collector plate (photo).
27Locate the engine rear plate on its dowels
by sliding it behind the flywheel (photo).
43 Engine ancillaries- refitting
1Bolt on the carburettor (Chapter 3). 2Fit the coolant pump and thermostat
housing (Chapter 2).
3Fit the alternator and tension the drivebelt
(Chapters 9 and 2).
4Fit the distributor (Chapter 4).
5Fit the fuel pump (Chapter 3).
6Fit the clutch (Chapter 5).
7Fit a new oil filter cartridge (Section 2 of this
Chapter).
44 Engine/transmission-
reconnection and refitting
3
1Offer the transmission to the engine making
sure that the clutch has been centralised as
described in Chapter 5 (photo).
1•32 1116 cc and 1301 cc engine
44.1 Offering transmission to engine42.27 Engine rear plate42.26 Tightening a camshaft carrier cover
nut
42.24C Engine mounting bracket with belt
tensioner plunger (arrowed)
42.24B Belt cover mounting stud42.24A Belt cover rear plate
42.21 Crankshaft pulley and nut42.20 Fitting crankshaft timing belt
sprocket42.19 Tightening flywheel bolts

2Draw the engine and transmission together
by screwing in the connecting bolts.
Refit lifting lugs and hose and wiring clips
(photo).
3Bolt the lower cover plate to the face of the
flywheel housing.
4Bolt the starter motor into position.
5Bolt the mounting brackets into place.
6Place the engine/transmission on the floor
ready for raising by hoist or jack into the
engine compartment.
7Raise the car and position it over the
engine/transmission.
8Hoist or jack the power unit upwards until
the left and right-hand mountings can be
connected (photos).9Remove the lifting mechanism and connect
the bottom mounting (photos).
10Connect the inboard ends of the
driveshafts with the transmission and the
outboard ends with the hub carriers.
11Reconnect the hub carriers with the
clamps at the base of the suspension struts.
Tighten the fixing bolts to the specified torque.
12Bolt the brake flexible hose support clips
to the suspension struts.
13Reconnect the tie-rod end balljoints
tightening the nuts to the specified torque.
14Reconnect the gearchange rods. The
easiest way to do this is to force the sockets
onto the ball studs using a pair of self-locking
grips (photo).15Refit the exhaust system and
reconnect the downpipe to the manifold
(photo).
16Screw on the driveshaft nuts and tighten
them to the specified torque. Have an
assistant apply the brake pedal hard to
prevent the driveshaft from turning.
17Refit the front roadwheels and lower the
car to the floor.
18Reconnect the carburettor fuel and
coolant hoses.
19Unplug the fuel hose and connect it to the
pump.
20Reconnect the choke and throttle controls
to the carburettor.
21Reconnect the coolant and heater hoses
1116 cc and 1301 cc engine 1•33
44.8B Left-hand engine mounting44.8A Raising engine/transmission into
engine compartment44.2 Lifting lug at bellhousing bolt
44.15 Exhaust downpipe flange nuts44.14 Connecting a gearchange rod ball
cup44.9B Lower mounting attachment bolts
44.9A Engine/transmission lower mounting44.8D Right-hand mounting bolted up44.8C Right-hand engine mounting
brackets
1

2
System type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “No loss” with radiator and integral expansion tank. Electric cooling
fan, belt-driven coolant pump, thermostat on cylinder head
General
Radiator fan cuts in . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 to 94ºC (194 to 201ºF)
Radiator fan switches off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 to 89ºC (185 to 192ºF)
Thermostat opens:
903 cc engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 to 89ºC (185 to 192ºF)
1116 cc and 1301 cc engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 to 87ºC (181 to 188.6ºF)
Fully open:
903 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100ºC (212ºF)
1116 cc and 1301 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95ºC (203ºF)
Expansion tank pressure cap rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.78 bar (11 lbf/in2)
Coolant
Capacity:
903 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6 litre (8.1 pint)
1116 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0 litre (10.6 pint)
1301 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 litre (10.9 pint)
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ethylene glycol based antifreeze
Torque wrench settingsNm lbf ft
Temperature sender switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 36
Coolant pump mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 25
Alternator adjuster and mountings nuts . . . . . . . . . . . . . . . . . . . . . . . . . 49 36
Chapter 2 Cooling and heating systems
For modifications, and information applicable to later models, see Supplement at end of manual
Coolant mixtures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Coolant pump - removal, overhaul and refitting . . . . . . . . . . . . . . . . 9
Cooling system - draining, flushing and refilling . . . . . . . . . . . . . . . . 2
Cooling system sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Description and maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Drivebelt - tensioning and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Fault finding - cooling and heating . . . . . . . . . . . . See end of ChapterHeater - dismantling, overhaul and reassembly . . . . . . . . . . . . . . . . 13
Heater unit - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Heating and ventilation system - description . . . . . . . . . . . . . . . . . . 11
Radiator - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Radiator fan thermostatic switch - removal, checking and refitting . 5
Radiator fan - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 6
Thermostat - removal, testing and refitting . . . . . . . . . . . . . . . . . . . . 4
2•1
Specifications Contents
1 Description and
maintenance
1
1The cooling system consists of a
front-mounted radiator with built-in expansion
tank, a coolant pump (belt-driven from the
crankshaft pulley) and a thermostatically-
controlled electric cooling fan.
2In order to assist rapid warm-up, athermostat is located in a housing at the
left-hand end of the cylinder head. The hose
connections to the thermostat housing vary
according to model.
3The heater is supplied with coolant from the
engine and incorporates a matrix and blower
with the necessary controls.
4The throttle valve plate block of the
carburettor is coolant-heated as a means of
improving fuel atomisation.
5Maintenance is minimal as in theory no
coolant should ever be lost from theexpansion tank. Regularly check that the
coolant level is between 50.0 and 70.0 mm
(1.97 and 2.8 in) above the MIN mark on the
tank with the engine cold. The need for
regular topping up will indicate a leak
somewhere in the system. If one cannot be
found suspect an internal leak in the engine
although this is usually confirmed by a rise in
the engine oil level and water on the dipstick
(photo). Any topping-up should be done using
an antifreeze mixture (see Section 3), not plain
water.
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

Engine idle speed
At normal operating temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800 to 850 rev/min
CO percentage at idle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 maximum
Torque wrench settingsNm lbf ft
Exhaust manifold nuts (903 cc) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 15
Exhaust and intake manifold nuts (1116 cc, 1301 cc) . . . . . . . . . . . . . . 28 20
Fuel pump nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 20
Carburettor mounting nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
3•4 Fuel system
2.11B Air cleaner mounting bracket and
pipe clip2.11A Air cleaner mounting studs (1116 cc)2.9 Crankcase vent hose at air cleaner
1 Description and
maintenance
1
1The fuel system consists of a rear-mounted
fuel tank, a mechanically-operated fuel pump
and a carburettor and air cleaner.
2On all engines except the 1301 cc a single
venturi downdraught carburettor is fitted. On
the 1301 cc version, a dual barrel carburettor
is fitted.
3Maintenance consists of periodically
checking the condition and security of the fuel
hoses to the pump and carburettor. The fuel
pump cannot be cleaned or repaired and in
the event of a fault developing, the pump
must be renewed.
4On ES versions, an electronic fuel cut-out
device is fitted which reduces fuel
consumption on overrun, see Chapter 9,
Section 33.
2 Air cleaner- servicing,
removal and refitting
1
1The air cleaner air intake draws air either
from the front of the car or from the outside of
the exhaust manifold according to ambient
temperature (photo).
2At an ambient temperature of 13ºC (55ºF)
and above, the SUN symbol should align with
the intake spout arrow head. Remove the
cover nuts and turn the cover.
3At an ambient temperature lower than this,
move the air cleaner cover until the
SNOWFLAKE symbol aligns with the intake
spout arrow head.
4At the intervals specified in “Routine
Maintenance” renew the air cleaner filter
element.
5To do this, remove the cover nuts and take
off the cover (photo).6Take out the filter element and discard it.
Wipe out the air cleaner casing (photo).
7Locate the new element and refit the cover
aligning the appropriate symbols.903 cc engine
8To remove the air cleaner from the 903 cc
engine, unscrew the nuts and take off the
cover. Lift out the filter element.
9Unbolt the air cleaner casing from the
carburettor flange and from the bracket on the
rocker cover. Disconnect the vent hose
(photo).
10Disconnect the warm and cool air intake
hoses from their collecting points and lift the
air cleaner from the engine.
1116 cc and 1301 cc engines
11Removing the air cleaner from the 1116 cc
engine is similar to that described for the
903 cc engine, but having a cylinder head
support bracket (photos).
2.6 Removing air cleaner element
2.5 Air cleaner cover2.1 Air cleaner hot air intake

19.7A Exhaust pipe support rings
17 Accelerator cable-
adjustment and renewal
2
1The socket type cable end fitting is
detached from the carburettor throttle lever
simply by prising it off the ball stud.
2Adjustment can be carried out by releasing
the locknut and turning the end fitting. With
the accelerator pedal fully depressed, check
that full throttle can be obtained at the
carburettor.
3To renew the cable, prise off the end fitting
from the carburettor throttle lever.
4Slip the cable sleeve from its retaining
bracket (photo).
5Working inside the car under the facia
panel, slip the cable from the fork at the top of
the accelerator pedal arm (photo). 6Withdraw the cable through the engine
compartment bulkhead.
7Fit the new cable by reversing the removal
operations, adjust as described in para-
graph 2.
18 Choke control cable-
removal and refitting
2
1Remove the air cleaner.
2Release the choke outer cable clamp and
the inner cable from the swivel on the choke
control lever (photo).
3The choke control is of lever type. To
remove it, extract its hinge screw, accessible
when the lever is pulled upwards (photo).
4Withdraw the choke cable assembly until
the inner cable can be released from the handcontrol lever and the choke warning lamp lead
unplugged.
5Withdraw the cable assembly through the
engine compartment rear bulkhead.
6Fit the new cable by reversing the removal
operations. Before tightening the inner cable
pinch screw at the carburettor, hold the choke
valve plate open and pull the control lever out
2.0 or 3.0 mm, then tighten the screw. This
will provide just enough free movement to
ensure that when the control is pushed fully in
the choke valve plate will remain fully open
even with engine movement slightly stretching
the cable.
19 Manifolds and exhaust
system
1
1The intake manifold on 903 cc engines is
integral with the cylinder head.
2On the other engines, the intake and
exhaust manifolds are mounted on the same
side of the cylinder head.
3A hot air collector plate is fitted over the
exhaust manifold from where the air cleaner
draws air when in the winter setting.
4When fitting a manifold, thoroughly clean
the cylinder head and manifold mating
surfaces, use a new gasket and tighten nuts
to the specified torque (photos).
5The exhaust system on 903 cc models is of
single downpipe, single silencer two section
type.
3•12 Fuel system
19.4C Fitting intake manifold complete
with carburettor19.4B Fitting exhaust manifold
19.4A Manifold gasket18.3 Extracting choke control lever screw
18.2 Choke cable at carburettor17.5 Accelerator pedal17.4 Throttle cable sleeve and bracket