1983 FIAT UNO oil change

4 Engine-
903 and 1299/1301 cc
Sump pan sealing strips (903 cc
engine) - modification
1The design of the sealing strips which go
between the sump pan and the main bearing
caps has been changed. Make sure that the
narrower side of the strip fits into the channel
in the sump pan.
1299 cc engine - description
2In April 1984, a 1299 cc engine was
introduced, progressively replacing the
1301 cc units used previously. The new
engine is identical to the 1301 cc engine
described in Chapter 1, with the exception of
having a slightly shorter stroke.
3However, as of approximately September
1987, the 1299 cc unit was phased out, being
progressively replaced by the 1301 cc engine
used initially.
4As mentioned above, the two engines are
all but identical, so identification of the unit
fitted should not be necessary in practice.
Consult a FIAT dealer if in doubt.
Rocker cover (903 cc engine) -
removal
5Before removing the rocker cover, it will be
necessary to remove the distributor, first.
Refer to Chapter 4 for more details.
Cylinder head (903 cc engine) -
refitting
6Modified cylinder head bolts are fitted to
903 cc models, from engine number 8581470.
When refitting the cylinder head, tighten each
head bolt, as described in Chapter 1, by the
torques and angles shown the Specifications
in this Chapter.
5 Engine-
999 and 1108 cc (FIRE)
Note:Later models are fitted with SPi fuel
injection. Where a procedure refers to a
carburettor, if applicable, replace with throttle
body.
PART A: GENERAL
Description
1Both of these engine types are designated
FIRE (Fully Integrated Robotised Engine),
being largely manufactured and assembled by
computer-controlled mechanical robots.
2The engine is of oversquare design, having
four cylinders and a belt-driven overhead
camshaft.
3The high torque of this engine enableshigher gear ratios to be used with the result
that fuel economy is exceptionally good.
4The cylinder head is of light alloy, while the
cylinder block is cast-iron.
5The camshaft is supported in three
bearings which have detachable caps.
6Valve clearances are maintained by shims
located in the cam followers (tappets).
7The cylinder head is of crossflow type
having the intake manifold (coolant-heated)
and exhaust manifold on opposite sides.
8The pistons have two compression rings
and one oil control ring and are connected to
the connecting rods by means of a gudgeon
pin which is an interference fit in the rod
small-end.
9The crankshaft is supported in five main
bearings. The upper section of the centre
bearing shell retains semi-circular thrust
washers to control crankshaft endfloat.
10The oil pump, which is of gear type, is
Supplement: Revisions and information on later models 13•19
Fig. 13.2 Cross-section view of the 999 and 1108 cc engine (Sec 5A)
Fig. 13.1 Correct method of fitting sump
pan sealing strip (Sec 4)
13

Sump pan -
removal and refitting Á
60Drain the engine oil.
61Unbolt and remove the cover plate from
the lower part of the flywheel housing (photo).
The two lower bolts retain the gearchange rod
support strut.
62Unscrew the sump pan securing screws
and pull the sump pan downwards to remove
it (photo). The joint sealant will require cutting
with a sharp knife to release the pan. Clean
away all old gasket material.
63A bead 3.0 mm in diameter of RTV
silicone instant gasket should be applied to
the sump pan flange and then the pan offered
up. Screw in the fixing screws and tighten to
the specified torque. Note the flange end
fixing screw nuts (photos).64Wait one hour before filling with engine oil.
65Refit the flywheel housing cover plate.Oil pump - removal,
checking and refitting#
66Drain the engine oil and remove the sump
pan as described in the last sub-Section.
Unscrew and remove the oil filter cartridge.
67Remove the timing belt.
68Lock the crankshaft against rotation either
by placing a block of wood between a
crankshaft web and the inside of the
crankcase or by jamming the flywheel starter
ring gear with a suitable tool.
69Unscrew and remove the crankshaft
sprocket bolt and take off the timing belt
sprocket. If it is tight, use two screwdrivers to
lever it off or use a two- or three-legged puller.
70Unbolt and remove the oil pick-up/filter
screen assembly. Note the sealing washer.71Extract the oil pump fixing bolts and
withdraw the pump.
72The oil pump incorporates a pressure
relief valve which can be removed for
examination by depressing the spring plunger
and pulling out the keeper plate (photos).
73If pump wear is suspected, check the
gears in the following way. Extract the fixing
screws and remove the rear cover plate. The
screws are very tight and will probably require
the use of an impact driver to release them
(photo).
74Check the clearance between the outer
gear and the pump housing using feeler
blades, and also the gear endfloat by placing
a straight-edge across the pump body and
checking the gap between the straight-edge
and gear face. If the clearances are outside
the specified tolerance, renew the oil pump
complete (photos).
13•24 Supplement: Revisions and information on later models
5B.74B Checking the oil pump gear
endfloat5B.74A Checking the oil pump gear-to-
housing clearance5B.73 Removing the oil pump rear cover
plate screws
5B.72B Oil pump relief valve components5B.72A Removing the oil pump relief valve
keeper plate5B.63B Sump pan flange end fixing screw
and nut
5B.63A Tightening a sump pan screw5B.62 Removing the sump pan5B.61 Removing the flywheel housing
cover plate

99Tighten the big-end bolts to the specified
torque (photo). The correct torque is
important as the bolts have no locking
arrangement. After tightening each big-end,
check that the crankshaft rotates smoothly.
100Repeat the operations on the remaining
piston/rod assemblies.
101Refit the oil pump pick-up assembly
using a new sealing ring.
102Refit the sump pan and the cylinder head
as described in earlier sub-Sections.
103Fill the engine with oil and coolant.
Pistons/connecting rods -
separation and piston
ring renewal
ª
104If the piston/connecting rods have been
removed in order to renew the piston rings,
refer to Chapter 1, Section 18, but note thatthe piston rings should be fitted so that the
word TOP is uppermost.
105If new pistons are to be fitted, it is
recommended that the gudgeon pins are
removed and refitted by a FIAT dealer as the
connecting rods must be carefully heated in
order to be able to push the gudgeon pin out
of the rod small-end, change the piston and
push the pin back into position. Locating the
gudgeon pin will require a special tool. The
gudgeon pin is a sliding fit in the piston but an
interference fit in the connecting rod.
106Refer to Fig. 13.6 for the correct
assembly of the piston and connecting rod.
Engine/transmission mountings
- renewal
107Refer to Chapter 1, Section 33. Three
mountings are used (photos).
PART C: ENGINE REMOVAL
AND DISMANTLING
Method of removal - general
1The engine, complete with transmission,
should be removed upwards out of the engine
compartment.
Engine/transmission -
removal and separation #
Warning: Refer to the beginning
of Section 9 before starting any
work.
2Mark the position of the hinges on the
underside of the bonnet and then, with the
help of an assistant, unscrew the hinge bolts
and lift the bonnet to a safe storage area.
3Drain the coolant; a cylinder block drain
plug is not fitted.
4Drain the engine and transmission oils.
5Disconnect the battery, negative lead first.
6Remove the air filter.
7Disconnect the radiator hoses from the
engine (photos).
13•26 Supplement: Revisions and information on later models
5C.7B Radiator hose at thermostat
housing5C.7A Radiator hose connection to coolant
distribution tube5B.107C Right-hand engine mounting
5B.107B Left-hand rear
engine/transmission mounting5B.107A Left-hand front
engine/transmission mounting
Fig. 13.6 Piston/connecting rod correctly
assembled - 999 and 1108 cc engine
(Sec 5B)
1 Piston grade (A) and directional arrow on
piston crown (towards timing belt)
2 Rod/cap matching numbers
3 Gudgeon pin offset in piston (0.9 to 1.1 mm)
Arrow indicates crankshaft rotation direction
Fig. 13.5 Piston ring arrangement on the
999 cc engine (Sec 5B)5B.99 Tightening a big-end cap bolt

8Disconnect the heater hose from the inlet
manifold.
9On fuel injection models, depressurize the
fuel system (refer to Section 9D). Disconnect
the fuel inlet and return hoses from the fuel
pump (photo) or throttle body, as applicable.
10Disconnect the brake servo vacuum hose
from the inlet manifold.
11Disconnect the throttle cable from the
carburettor, or throttle body as applicable.
12Disconnect the choke cable, if applicable
(photo).
13Disconnect the leads from the alternator.
14Disconnect the battery earth lead from the
transmission casing.15Disconnect the leads from the starter
motor and the HT lead from the ignition coil
(photo).
16Disconnect the coolant temperature
switch lead and the HT leads from the
distributor (photo).
17Disconnect the lead from the carburettor
fuel cut-off (anti-diesel) solenoid valve, where
applicable.
18Disconnect the lead from the oil pressure
switch (photo).
19Although not essential, removal of the
radiator is recommended as a precaution
against its damage during removal of the
power unit. Disconnect the wiring plugs from the fan and thermostatic switches
(photos).
20Disconnect the leads from the reversing
lamp switch on the transmission.
21Disconnect the clutch cable from the
release lever on the transmission.
22Disconnect the speedometer cable from
the transmission by unscrewing the knurled
ring.
23Working under the car, disconnect the
exhaust downpipes from the manifold and the
lower support bracket (photos).
24Disconnect the gearchange rods from the
levers on the transmission. One rod is
retained by a spring clip, the other by a
Supplement: Revisions and information on later models 13•27
5C.15 Ignition coil HT lead connection5C.12 Choke cable connection at
carburettor5C.9 Fuel hose identification at pump; inlet
hose (1), hose to carburettor (2), return
hose (3)
5C.19D Removing the radiator/fan
assembly5C.19C Radiator fan cut-out thermostatic
switch5C.19B Radiator fan motor wiring
connector
5C.19A Radiator retaining clip5C.18 Oil pressure switch5C.16 Coolant temperature switch
13

snap-on ball socket. Unbolt the gearchange
rod support bracket from the cover plate on
the flywheel housing (photos).
25Remove the screws from the driveshaft
inboard gaiter retaining plates (photos).
Expect slight oil loss.
26Disconnect the rear left-hand
transmission mounting. Do this by unscrewing
the two outer bolts not the centre one. The
engine will incline to the rear once the
mounting is released (photo).
27Raise the front of the car and support it
securely so that the front roadwheels hang
free.
28Remove the front roadwheels.
29Unscrew the tie-rod end balljoint taper pin
nuts, and then using a suitable “splitter” tool,
disconnect the balljoints from the eyes of the
steering arms.
30Unscrew the bolts from the clamps at the
bottom of the front suspension struts, tilt the
hub carriers outwards and partially disconnect
the driveshaft inboard joints from the
transmission.
31Support the weight of the engine/
transmission on a suitable hoist, and then
disconnect the right-hand and left-
hand front engine/transmission mountings
(photos).
32Unbolt and remove the engine mounting
brackets from the engine and the
transmission (photo).
33Raise the power unit slowly until the
driveshafts release from the transmission and
13•28 Supplement: Revisions and information on later models
5C.31B Left-hand engine mounting and
bracket5C.31A Right-hand engine mounting
disconnected5C.26 Left-hand rear (lower) transmission
mounting disconnected
5C.25B Driveshaft joint gaiter withdrawn5C.25A Two of the left-hand driveshaft
joint gaiter retaining plate screws
(arrowed)
5C.24C Gearchange rod support bracket5C.24B Gearchange rod with ball socket
connection
5C.24A Gearchange rod connecting pin
and spring clip5C.23B Unscrewing the exhaust pipe lower
support bracket bolt5C.23A Exhaust downpipe flange nuts

crankcase. If the shells are to be used again,
keep them with their respective bearing caps.
70The thrust washers which control
crankshaft endfloat are located in the
crankcase, and retained by the turned-over
edges of the centre main bearing shell.
71The engine is now fully stripped.
Examination and renovation
72The procedures for the following items are
essentially as described in Chapter 1, Sec-
tion 18.
Cylinder block and crankcase
Crankshaft and bearings
Flywheel
Oil seals and gaskets
Cylinder head
73Using a straight-edge, check the cylinder
head gasket surface for distortion. If it
exceeds the specified tolerance, it must be
surface ground by your dealer.74Refer to Chapter 1, Section 39, for
dismantling and renovation operations. Note
that single valve springs are fitted.
Oil pump
75Checking operations are described in
sub-Section B.
Pistons and connecting rods
76Refer to sub-Section B.
77If one or more connecting rods are
changed, it is important that its weight is
identical to that of the original. Use an
accurate balance to weigh them and remove
metal if necessary from the new rod in the
areas indicated in Fig. 13.7.
Camshaft and cam followers
78If the camshaft journals or bearings show
any sign of wear or scoring, then the
camshaft, or cylinder head, or both must be
renewed.
79The cam followers should be checked for
ovality using a micrometer. Unless unworn
they should be renewed.
Timing belt tensioner and timing belt
80The tensioner is a lubricant-sealed pulley,
and it should be tested for smooth and quiet
operation by turning it with the fingers. Any
evidence of roughness or rattle will indicate
the need for a new assembly (photo).81The timing belt should be inspected at
regular intervals for correct adjustment and
condition (see Section 3 or “Routine
maintenance” at the beginning of the Manual).
If there is evidence of worn teeth, cracking or
fraying, or oil contamination, renew the belt.
The vehicle manufacturers recommend that
the belt is renewed whenever it is removed,
and it should certainly be renewed at the
intervals specified in Section 3 or the main
“Routine maintenance” section at the
beginning of this Manual as a precautionary
measure against belt breakage and
consequent expensive engine damage.
PART D:
ENGINE REASSEMBLY AND
REFITTING
Reassembly - general
1Refer to Chapter 1, Section 19.
Complete reassembly#
2With the cylinder block/crankcase standing
on the work surface, fit the bearing half shells
into their crankcase seats (photo). Make sure
that the seats are perfectly clean as dirt or grit
trapped under the shell will cause binding
when the crankshaft is turned.
3The centre bearing crankcase web
incorporates the thrust washers held by the
lips of the bearing shell (photo).
4Oil the shells and lower the crankshaft into
the crankcase (photo).
5Fit the bearing shells into the main bearing
caps, again making sure that the shell seats
are perfectly clean (photo).
13•30 Supplement: Revisions and information on later models
5D.5 Main bearing cap and shell5D.4 Fitting the crankshaft5D.3 Crankshaft thrust washer at centre
bearing
5D.2 Main bearing shell in crankcase
Fig. 13.8 Checking a cam follower for
ovality - 999 and 1108 cc engine (Sec 5C)
Fig. 13.7 Metal removing areas (arrowed)
on connecting rod - 999 and 1108 cc
engine (Sec 5C)
5C.80 Timing belt tensioner

32Fit the hot air collector plate for the air
cleaner (photo).
33Refer to Section 10 and fit the distributor.
34Bolt on the timing belt cover.
35Fit the camshaft cover, using a new
gasket unless the original one is in perfect
condition.
Engine/transmission -
reconnection and refitting#
36Locate the engine in an upright position
on wooden blocks to allow for the greater
depth of the transmission flywheel housing
when it is joined to the engine.
37Make sure that the clutch driven plate has
been centralised, offer the transmission to the
engine and locate the flywheel housing on the
single stud and dowels.
38Tighten the connecting bolts to specifiedtorque, having located the lifting eye (photo).
39Bolt on the starter motor.
40Refit the cover plate to the flywheel
housing, but do not insert the lower bolts at
this stage as they retain the support bracket
for the gearchange rod.
41The engine and transmission are now
ready for refitting. The operations are a direct
reversal of the operations described earlier,
but observe the following points.
42Have the engine/transmission perfectly
horizontal and suspended on the hoist.
43Lower it into position very slowly until it is
possible to engage the driveshaft inboard
joints with the transmission.
44Continue lowering until the driveshafts
can be fully engaged and the mountings
reconnected. Remove the hoist.
45Tighten all nuts and bolts to the specifiedtorque. Note the method shown for
connecting the gearchange rod ball socket
using pliers (photo).
46Refill the engine with oil and coolant and
replenish the transmission oil.
Initial start-up after major
overhaul
47Refer to Chapter 1, Section 45.
6 Engine-
1301 cc Turbo ie
PART A: GENERAL
Description
1This engine is similar in design to the
1301 cc engine described in Chapter 1, but
the fuel and ignition systems are different, and
a turbocharger, oil cooler and intercooler are
fitted.
2Many dimensions and tolerances have
been altered for this engine, and reference
should be made to the Specifications at the
beginning of this Supplement.
3Operations which differ from those
described in Chapter 1 are given in the
following sub-Sections.
Lubrication system - description
4The lubrication system differs from the
non-Turbo 1301 cc engine in the following
respects.
5An oil cooler is fitted, which comprises a
matrix with inlet and outlet hoses connected
to the oil filter cartridge mounting base.
6A thermostatic control switch is fitted,
which diverts the oil flow through the matrix
only at oil temperatures above 84ºC (183ºF).
Note that a faulty switch will require renewal
of the complete oil filter mounting base.
7Special oil spray nozzles are located in the
crankcase main bearing webs, to cool the
underside of the pistons.
8The ball-type valves in the nozzles open
when the engine oil pressure reaches 1.2 bars
(17.4 lbf/in
2).
9An oil pressure sender unit is screwed into
Supplement: Revisions and information on later models 13•33
5D.45 Connecting ball socket type
gearchange rod5D.38 Lifting eye on flywheel housing
flange5D.32 Air cleaner hot air collector plate
Fig. 13.10 Cutaway view of the 1301 cc Turbo ie engine (Sec 6A)
13

Engine oil cooler -
removal and refittingÁ
23The oil cooler is mounted behind the front
bumper/spoiler (photo).
24Disconnect the oil flow and return hoses,
either from the cooler or the oil filter cartridge
mounting base. Be prepared for some
leakage of oil (photos).
25Unscrew the mounting bolts and remove
the oil cooler heat exchanger (photo).
26When refitting, make sure that the banjo
union sealing washers are in good condition.
PART C: ENGINE REMOVAL,
DISMANTLING, REASSEMBLY
AND REFITTING
Engine/transmission -
removal and separation
#
Warning: Refer to the beginning
of Section 9 before starting any
work.
1Refer to Chapter 1, Section 35, and carry
out the operations described in paragraphs 1
to 11.
2Disconnect the excessive air pressure
switch from the inlet manifold.
3Disconnect the ducts and remove the
airflow meter.
4Disconnect the leads from the spark plugs
and the distributor LT connector, and unbolt
and remove the distributor from the rear end
of the camshaft carrier.
5Disconnect the fuel return hose from the
pressure regulator. 6Disconnect the fuel inlet hose from the
injector rail.
7Disconnect the wiring plugs from the fuel
injectors.
8Disconnect the leads from the oil pressure
sender unit, the low oil pressure switch and
the coolant temperature switch.
9Remove the hose/pipe assemblies from the
intercooler.
10Disconnect the throttle control rod at the
balljoint.
11Disconnect the hoses and ducts from the
turbocharger and the mechanical bypass
valve.
12Disconnect the leads from the engine
speed and anti-knock sensors.
13Raise the front of the car and support it
securely. As the engine/transmission will
eventually be lowered to the floor, make sure
that there is sufficient clearance under the
front end for the assembly to be withdrawn. If
the car is over an inspection pit, then the car
need only be raised enough to lift the
roadwheels from the floor.
14Remove the front roadwheels.
15Disconnect the transmission earth cable.
16Working under the car, remove the engine
shields from under the wheel arches.
17Remove the engine oil cooler, and the
intercooler.
18Unscrew the fixing screws and disconnect
the driveshafts from the flanges at the
transmission final drive. The right-hand
driveshaft will not release until the upper bolt
on the suspension strut-to-hub carrier clamphas been removed, and the hub assembly
tilted downwards.
19Disconnect the exhaust downpipe from
the manifold, and then remove the front
section of the exhaust system.
20Disconnect the coolant return pipe from
the turbocharger.
21Disconnect the gearchange control rods
from the transmission selector rod. Do this by
unscrewing the self-locking nut from the bolt
which connects the clevis fork.
22Attach suitable lifting gear to the engine
lifting eyes, and take the weight of the
engine/transmission.
23Disconnect the left-front, centre-rear and
the right-hand engine/transmission mountings.
Do this by removing the bolts from the
diamond-shaped mounting plates there is no
need to disturb the flexible mounting centre
bolts.
24Lower the engine/transmission to the floor
and withdraw it from under the car.
25Carry out the operations described in
Chapter 1, Section 35, paragraphs 27 to 31.
Engine dismantling and
reassembly
26The operations are essentially as
described for the 1301 cc engine in Chapter 1,
but reference must be made to Sections 9
and 10 of this Chapter for the procedures for
removing and refitting the components of the
fuel injection, turbocharger and ignition
systems.
Engine/transmission -
reconnection and refitting
27The operations are a reversal of those
described in paragraphs 1 to 25, but
otherwise the following (photo).
a) Tighten all nuts and bolts to the specified
torque.
b) Use a new gasket at the exhaust
downpipe-to-manifold flange.
c) Check and adjust the clutch pedal travel.
d) Refill the cooling system.
e) Refill the engine and transmission with oil.
f) Reconnect the battery, negative lead
last.
13•36 Supplement: Revisions and information on later models
6C.27 Filling the engine with oil6B.25 Oil cooler mounting bolts (arrowed)
6B.24B Connections at oil filter cartridge
mounting base6B.24A Oil cooler pipe connection
(arrowed)6B.23 Oil cooler