1997 FIAT PUNTO Section 5
[x] Cancel search: Section 5Page 68 of 225
2B*8 DOHC (16-valve) petrol engine in-car repair procedures
8.3a Disconnect the LT wiring plugs from the two Ignition coils ... 4 Dip the new oil seal in oil then offer it up to the oil pump casing making sure that the sealing Hps are facing inwards. 5 Using a suitable tubular drift, drive the oil seal squarely into the casing. Remove the adhesive tape, 8 Reftl the crankshaft sprocket and timing belt wrth reference to Sections 5 and
Rear (left-hand side) oil seal Note: The following paragraphs describe renewal of the rear oil seal leaving the housing in position. Refer to Chapter 20 for details of removing ihe housing. 7 Remove the flywheel as described In Section 11. 8 Using a suitable hooked Instrument, remove the oil seal from the rear oil seal
L •
~ 1 8.8a Lift the cylinder head extension slightly and insert the tools {shown with cylinder head removed for clarity)...
8.3b ... then unscrew the mounting bolts end romove the ignition colls housing taking care not to damage the surface of the crankshaft. 9 Clean the seating In the housing and the surface of Ihe crankshaft. Check the crankshaft for burrs which may damage the sealing lip ol Ihe new seal, and If necessary use a Tine file to remove them. 10 Dip the new seal In clean engine oil and carefully locate it over Ihe crankshaft rear flange making sure that it is the correct way round. 11 Progressively tap the oil seal into the housing keeping it square to prevent distortion. A block of wood Is useful for this purpose. 12 Refit the flywheel with reference to Section 11,
8 Cylinder head extension -removal and refitting ^
Removal 1 Remove the timing bolt as described in Soction A. 2 Identify the two HT leads for position then disconnect them from the coil HT terminals. 3 Disconnect the LT wiring plugs from the two ignition coils, then unscrew the mounting bolts and remove the ignition coils from the and of the cylinder head extension {see illustrations). A Undo the bolt and remove the resonator support bracket from Ihe top of the cylinder head extension,
8.8b ... thon remove the cylinder head extension
8.G Unscrew tho protective caps covering the cylinder head extension retaining bolts
5 Unscrew the protective caps covering the cylinder head extension retaining bolts (see Illustration). 6 To retain the cam followers in place as the cylinder head extension Is removed. Flat special tool No 1860988000 will bo required. This tool consists of two strips ol suitably slotted thin metal angle which sDp between the cylinder head extension and cylinder head mating faces as the extension Is lifted off. The tool holds the cam followers in place in the extension allowing the assembly to be withdrawn without fouling the Inlet and exhausl valves, The tools are refetJvety inexpensive and readily available from Fiat dealers. Suitable alternatives can be fabneated, If desired, usrnj thin metal angle strip cut to the dimensions shown (see Tool tip). 7 Progressively slacken and remove the boll$ securing the cylinder head extension to the cylinder head. 8 Lilt tho cylinder head extension up very slightly, keeping it square to the cylindei head. Slip the toots in place to hold the cam followers, then lift the extension off the cylinder head (see illustrations). Recover the gasket between the two assemblies. 9 Dismantling and Inspection procedures lor the cylinder head extension and camshafts are given in Section 9. Refitting 10 Ensure thai Ihe mating faces of the cylinder head and extension aro thorough^ cleaned, with all traces of old gasket removed, then locate a new gasket on Ihe cylinder head (see Illustration).
8.10 Locate a new gasket on the cylinder head
To make a cam follower retaining tool, obtain two lengths of 1hln metal angle and cut both to the dimensions (In mm) shown
Page 69 of 225
2B*9 DOHC (16-valve) petrol engine in-car repair procedures
8.12 Rofit tho cylinder head extension retaining bolts and tighten them to tho specified torque 11 Locate the cam follower retaining tools in position Ihen lower the extension assembly onto the cylinder head. When all the cam followers have engaged their respective valves, remove the tools. 12 Refit tho retaining bolts and tighten them progressively to pull the extension down onto
the
cylinder head. Do this slowly and carefully
as the
vaivo springs will be compressed during Ihfs operation and it is essential to keep the extension square and level as the bolts are lightened. Once all the bolts are Initially Bghloned. progressively tighten them further to
the specified
torque (see illustration). 13 If necessary renew the O-rlng seals on the protective caps covering the cylinder head extension retaining bolts (see illustration).
Refit
the caps and tighten them securoly. 14 Refit the resonator support bracket to the
Icp of
the cylinder head extension.
8.13 Renew the O-ring seals on the protective caps covering the cylinder head extension retaining bolts 15 Refil the ignition coils and reconnect Ihe wiring. 16 Refit the timing belt as described in Section 4.
9 Camshafts and cam ^ followers -
removal,
S inspection and refitting ^
Removal 1 Remove the cylinder head extension as described in Section 8. 2 Place the assembly upside down on a bench and lift off the cam follower retaining tools, 3 Remove the cam followers from their locations In the cylinder head extension and place them In an oil tight compartmented box
labelled 1 to 8 (inlet) and 1 to 8 (exhaust) (see illustration). Alternatively, place them into individual storage jars or containers suitably marked. Fill the box or the jars with clean engine oil until each cam follower is just submerged, 4 Undo the camshaft sprocket retaining bolt while holding the sprocket with a suitable tool as described In Section 4. 5 Remove the camshaft sprocket, then undo the bolt and nut and remove the cover plate over the inlet camshaft (see Illustrations), 6 At the other end of the cylinder head extension, undo the nuts and remove the end cover (soe Illustration). Recover the gasket. 7 Undo the two bolts securing the camshaft drive gears to the inlet and exhaust camshafts (see illustration). The camshaft locking tools used in the timing belt removal procedure (which should still be in place) are sufficient to prevent the camshafts rotating while the gear retaining bolts are undone. Remove the bolts and withdraw the camshaft gears. 8 Remove the camshaft locking tools. 9 Carefully remove the Inlet camshaft from the cylinder head extension (see illustration). Suitably mark the camshaft IN to avoid confusion when refitting. 10 Punch or drill a small hole in the exhaust camshaft oil seal. Screw a self-tapping screw into the hole, and pull on the screw with pliers to extract the seat (soe illustration). 11 Carefully remove Ihe exhaust camshaft from the cylinder head extension (soe illustration). Suitably mark the camshaft EX to avoid confusion when refitting.
JJ Remove the cam followers from their 9.5a Remove the camshaft sprocket... locations in the cylinder head extension
9.5b ... then undo the bolt and nut and remove the cover plate over tho inlet camshaft
9.6 Undo the nuts and remove the end cover
9.7 Undo the two bolts securing the camshaft drive gears to the inlet and exhaust camshafts 9.9 Carefully remove tho Inlet camshaft from the cylinder head extension
Page 71 of 225
DOHC (16-valve) petrol engine in-car repair procedures 2B*11
camshaft cover plate... 25 Locate the cam follower retaining tools in position and refit the cylinder head extension
as
described In Section 8.
10
Cylinder head - &
removal and
refitting S
Removal Note; The cylinder head bolts are of special
sekned
design and a Fiat tool should be
obtained
to unscrew them. A Ton key will not
JSt however
in practise It was found that a dose-httlng Alien key could be used as an itemative. 1 Drain the cooling system as described in Chapter 1A. 2 Remove the cylinder head extension as oescAbed
m
Section 8. 3 Disconnect the radiator hose from the thermostat housing on the left-hand end of
Ihe
cylinder head. 4 Disconnect the heater hose from the outlet
at the
rear of the cylinder head. 5 Disconnect the coolant temperature sensor md temperature gauge sensor wiring plugs
torn
the left-hand end of the cylinder head. 9 Undo the engine oil dipstick tube bracket retaining bolt and the two bolts securing the wing harness support clips to the inlet marriold lower section. 7 Undo Ihe retaining nuts and separate the ixhaust system front pipe from the exhaust manifold flange.
8
Check that nothing remains attached to the cinder head likely to impede removal. It Is assumed that the head will be removed complete with exhaust manifold and inlet manifold lower section. 9 Unscrew the cylinder head bolts half a turn K
e
time in the reverse order to that shown in (lustration 10.20a. When the bolts are free. «mwe them from their locations.. Id Lift the cylinder head from the block. If it is stuck tight rock the head to break the joint by mans of the manifolds. On no account drive
levers
into the gasket Joint, nor attempt to tap tf« head sideways, as it is located on positioning dowels. 11 Remove and discard the cylinder head gasket.
JK'
l^. 9.22b ... then apply RTV gasket sealant to the cover plate contact face 12 Refer to Chapter 20 for cylinder head dismantling and inspection procedures. Preparation for refitting 13 The mating faces of the cylinder head and cylinder block must be perfectly dean before refitting the head. Use a hard plastic or wooden scraper to remove all traces of gasket and carbon; also clean the piston crowns, Take particular care when cleaning the piston crowns as the soft aluminium alloy is easily damaged. Make sure that the carbon is not allowed to enter the oil and water passages -this Is particularly important for the lubncahon system, as carbon could block the oil supply to the engine's components. Using adhesive tape and paper, seal the water, oil and bolt holes in the cylinder block. To prevent carbon entering the gap between the pistons and bores, smear a little grease In the gap. After cleaning each piston, use a small brush to remove all traces of grease and carbon from the gap. then wipe away the remainder with a clean rag. Clean all the pistons in the same way. 14 Check the mating surfaces of the cylinder block and the cylinder head for nicks, deep scratches and other damage. If slight, they may be removed carefully with a file, but If excessive, machining may be the only alternative to renewal. If warpage of the cylinder head gasket surface Is suspected, use a straight-edge to check it for distortion. Refer to Part 0 of this Chapter if necessary. 15 Check the condition of the cylinder head bolts, and particularly their threads, whenever they are removed. Wash the bolts In a suitable
sequence
9.24 Lubricate the cam followers and place them in position in their respective bores solvent, and wipe them dry. Check each bolt for any sign of visible wear or damage, renewing them if necessary.
Refitting 18 Before refitting the assembled cylinder head, make sure that the head and block mating surfaces are perfectly clean, and that the bolt holes in the cylinder block have been mopped out to clear any oil, 17 The now gasket should not be removed from its nylon cover until required for use. Fit Ihe gasket dry, and make sure that the mating surfaces on the head and block are perfectly clean. 18 Place the gasket on the cylinder block so that the word ALTO can be read from above. 19 Lower the cylinder head onto the block so that it locates on the positioning dowel. 20 The cylinder head bolt threads must be clean and lightly lubricated. Screw the bolts in finger-tight then working progressively and in the sequence shown, lighten all the cylinder head bolts to the Stage 1 torquo setting given In the Specifications, using a torque wrench and a suitable socket. With all the bolts tightened to their Stage 1 setting, working again in the specified sequence, first angle-tighten the bolts through the specified Stage 2 angle, then again through the Stage 3 angle, using a socket and extension bar. It Is recommended that an angle-measuring gauge Is used during this stage ot tightening, to ensure accuracy (see Illustrations). 21 Reconnect the exhaust system front pipe to the manifold using a new flange gasket.
10.20b Tighten the cylinder head bolts to the Stago 1 torque setting ...
Page 72 of 225
2B*12 DOHC (16-valve) petrol engine in-car repair procedures
... then through the Stage 2 end Stage 3 angle
22 Refit the engine oil dipstick tube bracket retaining bolt and the two bolts securing the wiring harness support clips to the inlet manifold lower section. 23 Connect the coolant temperature sensor and temperature gauge sensor wiring plugs. 24 Connect the radiator hose lo the thermostat housing and the heater hose to the cylinder head outlet. 25 Refit the cylinder head extension as described in Section 8. 26 On completion, refill tha cooling system as described In Chapter 1A.
11 Flywheel -removal, Inspection arid refitting
12 Engine mountings -inspection and renewal
Refer to Chapter 2A, Section 11.
13 Sump -removal and refitting
R6fer to Chapter 2A. Section 12.
14 Oil pump and pick-up tube -removal, Inspection and refitting
Refer to Chapter 2A, Section 10. Refer to Chapter 2A. Section 13.
Page 74 of 225
2C*2 Diesel engine in-car repair procedures
1 General information
Using this Chapter Chapter 2 is divided Into four Parts; A. 8, C and 0. Repair operations that cart be carried out with the engine in the vehicle are described In Part A, SOHC (B-valve) petrol engines. Part B, DOHC (16-valve) petrol engines and Part C. diesel engines, Part D covers the removal of the engine/transmission as a unit, and describes the engine dismantling and overhaul procedures. In Parts A. 8 and C. the assumption Is made that the engine is installed in Ihe vehicle, with all anciliaries connected If the engine has been removed for overhaul, the preliminary dismantling information which precedes each operation may be ignored.
Engine description Both normally aspirated (non-turbo) and turbocharged diesel engines are fitted to the Punto range. The engines together with their codes are given in the Specifications at the start of lhis Chapter. The engines are water-cooled, single-overhead camshaft. In-line lour cylinder units with cast-iron cylinder blocks and aluminium-alloy cylinder heads. The engine is mounted transversely at the front of the vehicle, with the transmission bolted to the left-hand side of the engine. The cylinder head carries the camshaft which is driven by a toothed timing belt. It also houses the inlet and exhaust valves which are closed by single coll valve springs and run in valve guides pressed into the cylinder head. The valves are operated by cam followers fitted over each valve, and the clearances are adjusted by shims positioned between the followers and the camshaft lobes. The camshaft is supported by four bearings • the end bearings are machined in the cylinder head and the remaining bearings have caps bolted to the cylinder head. The cylinder head contains integral oiiways which supply and lubricate the camshaft and followers and it also Incorporates renewable swirl chambers. The crankshaft Is supported by five main bearings, and endfloat Is controlled by a thrust bearing fitted on the rear main bearing. All diesel engines are fitted with a brake servo vacuum pump dnven from the left-hBnd end of the camshaft. Engine coolant is circulated by a pump, driven by the auxiliary drivebeit. For details of the cooling system refer to Chapter 3. Lubricant is circulated under pressure by a pump, driven from the front of the crankshaft. Oil is drawn from the sump through a strainer, and then forced through an externally-mounted, replaceable screw-on filter. From there, it is distributed to the cylinder head.
where il lubncates the camshaft journals and followers, and also to the crankcase, where it lubricates the main bearings, connecting rod big- and small-ends, gudgeon pins and cylinder bores. Oil jets are fitted to the base of each cylinder bore - these spray oil onto the underside of the pistons, lo Improve cooling. An oil cooler is also fitted to reduce the temp-erature of oil before it re-enters the engine.
Repair operations possible with the engine in the car The following work can be carried out with the engine in the can a) Compression pressure - testing b) Auxiliary drivebeit - removal and refitting (refer to Chapter rej c) Valve clearances • checking and adjustment (refer to Chapter 1B) d) Camshaft cover - removal and refitting e) Tim/ng belt and covers • removal and refitting 0 Timing belt tensioner and sprockets -removal and refitting g) Cylinder head - removal and refitting' h) Camshaft and cam followers - removal end refitting' I) Camshaft oil seal - renewal j) Crankshaft oil seals - renewal k) Flywheel • removal, inspection and refitting I) Engine mountings - inspection and renewal m)Sump • removal and refitting n) Oil pump and pick-up tube assembly -removal, inspection and refitting 'Cylinder head dismantling procedures are detalfed In Chapter 2D, with details of camshaft and cam follower removal. Note: It ts possible to remove the pistons and connecting rods (after removing the cylinder nead and sump) without removing the engine. However, this is not recommended. Work of this nature is more easily and thoroughly completed with the engine on tho bench as described in Chapter 2D.
2 Location of
TDC
on ^ No
1
cylinder ||
General information 1 The camshaft and fuel Injection pump are driven by the crankshaft, by means of sprockets and a timing belt. All three sprockets rotate in phase with each other and this provides the correct valve and injection pump timing as the engine rotates. When the timing bell is removed during servicing or repair, it is possible for the camshaft, injection pump and crankshaft to rotate independently of each other and the correct timing Is then lost.
2 It
Location of TDC on cylinder No
1
6 Remove the air inlet ducting as described ft Chapter 4C, Section 2. 7 Remove the heater glow plugs with reference to Chapter 5C. Due to the high compression ratio of diesel engines this Is necessary to allow the engine to be turned by hand. 8 Unscrew the mounting bolts and move the coolant expansion tank to one side for access to the timing covers. Release the hose from the clips on Ihe camshaft cover. 9 Release the toggle clips and remove the upper timing cover (see illustration),
2.9 Removing the upper timing cover
Page 76 of 225
2C*2 Diesel engine in-car repair procedures
4.4a Unbolt the engine oil dipstick tube...
3 Cylinder compression test
Note: A compression tester specifically designed for diesef engines must be used for this test. 1 When engine performance Is down, or if misfiring occurs, a compression test can provide diagnostic clues as to the engine's condition, If the lest is performed regularly, it can give warning of trouble before any other symptoms become apparent. 2 A compression tester specifically Intended for diesel engines must be used, because of the higher pressures involved. The Ie6ter is connected to an adapler which screws Into the glow plug or injector hole. It is unlikely to be worthwhile buying such a tester for occasional use. but it may be possible to borrow or hire one • if not. have the test performed by a garage. 3 Unless specific instructions to the contrary are supplied with the tester, observe the following points: 9) The battery must bo in a good state of charge, the air titter must be clean, end the engine should be at normal operating temperature. b) AH the in/actors or glow plugs should be removed before starting the lest. If removing the injectors, also remove the flame shield washers, otherwise they may be blown out. c) The stop solenoid must be disconnected.
4.4b ... and remove it from the rubber grommet in the oil pump housing
fo prevent the engine from running or fuel from being discharged. 4 There is no need to hold the accelerator pedal down during the test, because the diesel engine air inlet is not throttled. 5 The cause of poor compression Is less easy to establish on a diesel engine than on a petrol one. The effect of introducing oil into the cylinders (wet testing) Is not conclusive, because there is a risk that the oil will sit in the recess on the piston crown, instead of passing to the rings. However the following can be used as a rough guide to diagnosis. 6 All cylinders should produce very similar pressures; a difference of more than 5 bars between any two cylinders Indicates the existence of a fault. Note that the compression should build up quickly In a healthy engine; low compression on the first stroke, followed by gradually-increasing pressure on successive strokes, indicates worn piston rings. A low compression reading on the first stroke, which does not build up during successive strokes, indicates leaking valves or a blown head gasket (a cracked hoad could also be the cause). 7 A low reading from two adjacent cylinders Is almost certainly due to the head gasket having blown between them: the presence of coolant In the engine oil will confirm this,
Leakdown test 8 A leakdown test measures the rate at which compressed air fed into the cylinder Is lost. It is an alternative to a compression test, and in many ways it is better, since the escaping air provides easy identification of where pressure loss is occurring (piston rings, valves or head gasket). 9 The equipment needed for leakdown testing is unlikely to be available to the home mechanic. If poor compression Is suspected, have the test performed by a suitably-equipped garage.
4 Timing belt and covers -removal
and
refitting
Note: Fiat specify the use of a spec/a/ timing belt tension measuring tool to correctly set the timing belt tension. If access to this equipment cannot be obtained, an approximate setting can be achieved using the method described below. If the method described is used, the tension must be checked using the special tool at the earliest possible opportunity. Do not drive the vehicle over large distances, or use high engine speeds, until the belt fens/on rs known to be correct. Refer to a Fiat dealer for advice.
General Information 1 The function of the timing belt is to drive the camshaft and fuel injection pump. Should the belt slip or break in service, the valve timing will be disturbed and piston-to-valve contact
will occur, resulting In serious engine damage. 2 The timing bolt should be renewed at the specified intervals (see Chapter 1B), or earlier If It is contaminated with oil. or If It is at al noisy In operation (a scraping noise due to uneven wear),
Removal 3 Set the engine at TDC on No 1 cylinder
as
described in Section 2. 4 Unbolt and remove tho engine oil dipstick tube and remove It from the rubber gromme! in the oil pump housing (see illustrations), 5 Before removing the timing belt check rts tension by turning the belt through 90" with finger and thumb midway between u* injection pump and camshaft sprockets. This will give you an Idea of the tension to apply when refitting, assuming the tension is already correct. Also note the position of the tensions pulley as a reference mark. 6 Release tho nut on the timing bea tensioner, move the tensioner pulley away from the belt and retlghten the nut to hold the pulley in the retracted position. 7 If the timing belt is to be re-used, use white paint or chalk to mark the direction of rotation on the belt (if markings do not already exist), then slip the belt off the camshaft, crankshaft and injection pump sprockets, and the idler and tensioner pulleys. Caution: If the belt appears to be In good condition and can be re-used, it fs essential that It Is refitted the same
wsy
round, otherwise accelerated wear will result, leading fo premature failure. 8 Check the timing belt carefully for any signs of uneven wear, splitting, or oil contamination. Pay particular attention to the roots of the teeth. Renew it if there is the slightest doutt about its condition. If the engine is undergoing an overhaul, renew the belt as a matter of course, regardless of its apparent conditio*. The cost of a new belt Is nothing compa/ed with the cost of repairs, should the belt freak in service. If signs of oil contamination art found, trace the source of the oil leak and rectify It. Wash down the engine timing baft area and all related components, to remove
sd
traces of oil.
Refitting 9 Before refitting, thoroughly clean the tknmg belt sprockets. Check that the tensioner and idler pulleys rotate freely, without any sign ol roughness. If necessary, renew them as described in Section 5. 10 Ensure that the crankshaft, camshaft and injection pump sprockets are still at their TDC positions as described In Section 2. 11 Engage the timing belt with the crankshaft sprocket, then locate it around the idler pufiey and onto the Injection pump sprocket making sure that it is kept taught. Continue to locate! around the camshaft sprocket and finally around Ihe tensioner pulley (see Illustration) Ensure the belt teeth seat correctly on Ihe sprockets.
Page 77 of 225
Diesel engine in-car repair procedures
2C*11
C«/ffor>: Where applicable observe the drnctbn of rotation markings on the belt. 12 Tension the timing belt by turning the eccentrically-mounted tensioner clockwise: two ities are provided in the side of the tensioner ftb for this purpose - a pair of sturdy right-ircfed circiip pliers can be used to do this or iftemaiively two bolts and a long screwdriver
may be
used. Fiat use a special tensioner tool
located in
the hotos - this consists of a calibrated rod
and
weight. The weight is positioned 60 mm tog the rod to provide the correct tension to the belt, then the tensioner nul is tightened. Tgttn tho tensioner nut to the specified torque
(see
illustrations) 13
If the
tensioner tool Is not available, test the wsicn by grasping the timing belt between the li^er and thumb midway between the camshaft and injection pump pulleys, and Using il through 90" (see paragraph S).
Caution: The above procedure serves only as a rough guide to setting the belt tension. The tension must be checked accurately by a Fiat dealer using the spec/a/ fens/oner tool, at the earliest opportunity. 14 Tum the engine two complete turns clockwise, check that all the timing marks are still aligned then recheck the timing belt tension. If necessary carry out the tensioning procedure again, 15 Refit the components disturbed for access, using the reverse of the removal procedure and bearing In mind the following points: a) Tighten all nuts and bolts to the specified torque, where given. b) Refit the auxiliary dnvebelt(s) as described in Chapter 18.
5 Timing belt tensioner ^ and sprockets - removal, ^ inspection and refitting ^
1 Follow the procedure for removing the timing belt In Section 4, however it is not necessary to completely remove the belt from the timing sprockets provided it is kept fully engaged with them. 2 Unscrew the nut and slide the tensioner off the mounting stud (see illustrations).
Inspection 3 Wipe the tensioner clean but do not use solvents that may contaminate the bearings. Spin the tensioner pulley on its hub by hand. Stiff movemeni or excessive freeplay Is an Indication of severe wean the tensioner is not a serviceable component, and should be renewed, Refitting 4 Slide the tensioner pulley over the mounting stud and screw on the nut. 5 Refer to Section 4 and refit the timing belt.
Timing belt idler pulley
Removal 6 Remove Ihe timing belt as described In Section 4. 7 Unscrew the mounting bolt and remove the idler pulley from the front of the cylinder block (see illustration). Inspection 8 Wipe the idler clean but do not use solvents that may contaminate the bearings. Spin the idler pulley on Its hub by hand. Stiff movement or excessive freeplay Is an Indication of severe wear; the Idler is not a serviceable component, and should be renewed. Refitting 9 Refit the idler to the front of the block and tighten the bolt to the specified torque (see illustration). 10 Refer to Section 4 and refit the liming belt.
Timing belt tensioner
Removal
5.9 Tightening the idler pulley mounting bolt
Page 78 of 225
2C*2 Diesel engine in-car repair procedures
5.11 Special Fiat tool necessary to accurately position the camshaft before fitting the sprocket
Camshaft sprocket Removal 11 Remove the timing belt as descnbed in Section 4. A special Rat tool (see illustration) is necessary to position the camshaft before refitting the sprocket, however il the original camshafl Is being re-used, use of the special tool can be ovoided by accurately marking the camshaft position before removing the sprocket. Caution: On later 1996 models the camshaft sprocket can be moved In either direction on tho camshaft location dowel. 12 The camshaft sprocket must now oe held stationary whilst the retaining bolt is loosened. This is no problem on later models where the sprocket incorporates holes, however some early models have a sprocket without holes • on this type Fiat technicians use a special tool
V*— r^r
To make a camshaft sprocket holding tool, obtain two lengths of steel strip about 6 mm thick by 30 mm wide or simllar, one 600 mm long, the other 200 mm long (all dimensions approximate). Bolt the two strips together to form a forked end, leaving tho bolt slack so that the shorter strip can pivot freely. At the end of each 'prong' of the fork, secure a bolt with a nut and a locknut, to act as the futcrums; theso will engage with the cut'Outs In the sprocket, and should protrude by about 30 mm
which clamps on the sprockot teeth. If this tool is not available, it may be possible to make up a similar tool. On later models a sprocket holding tool can easily be made (see Toot Tip). 13 On 1996-on models mark the position of the camshaft in relation to the cylinder head.
5.14a Unscrew and remove the bolt and washer...
This is best achieved by removing tho vacuum pump from the flywheel end of the head and marking the head in relation to Ihe drive slot in ihe end of the camshaft. Note the location of the hose and bracket when removing tha vacuum pump (seo illustration). 14 Unscrew and remove tho boll and v/ashof and withdraw the sprocket from the end of tha camshaft (see Illustrations). Note tha location peg on the camshafl. Inspection 15 With the sprocket removed, examine the camshaft oil seal for signs of leaking. If necessary, rater to Section 7 and renew it 16 Check the sprocket teeth for damage. 17 Wipe clean the sprocket and camshaft mating surfaces-Refitting 18 Locate the sprocket on the end of the camshaft. On J996-on models chock that the camshaft is positioned accurately to tho previously made marks and also make sura thai the TOC mark on Ihe sprocket Is aligned with the mark on the Inner timing cover. If avoiiablo use the special Fiat toot to locate the camshaft correctly. Rofil the bolt and washer and tighten lo the specified torque while holding the camshalt sprocket stationary using the method descnbed previously. Recheck all alignment marks. 19 Refit the timing belt as described in Section 4.
Crankshaft sprocket Caution: The crankshaft sprockot retaining bolt has a left-hand thread. Removal 20 Remove the timing belt as described in Section 4. 21 Working beneath the engine unbolt and remove the flywheel lower cover, than hold the flywheel stationary preferably using a tool which engages the flywheel starter ring gear (see Section 10). Alternatively have an assistant engage a wide-bladed screwdriver with the starter ring gear 22 Unscrew and remove (he crankshaft sprocket retaining bolt (left-hand thread), washer and spacer and slide the sprocket off the end of the crankshaft (see illustrations). It is quite tight and il will be necessary to use a
5.14b ... and remove the sprocket from tho end of the camshaft 5.22a Unscrew and remove the bolt, washer and spacer... 5.22b ... and remove the crankshaft sprocket