Section 5 FIAT PUNTO 1997 176 / 1.G Owner's Manual

2A*10 SOHC (8-valve) petrol engine in-car repair procedures
4.7 Removing the timing belt cover bottom bolt
7 Unbolt and remove the timing belt cover. Note the bolt located at the bottom of the cover, this can easily be overlooked (see illustration), 8 Undo the three bolts and remove the crankshaft pulley from the sprocket (see illustration). 9 Set the engine al TDC on No 1 cylinder as described in Section 2. 10 Release the nut on the timing belt tensioner, move the lensloner pulley away from the belt and retighten the nut to hold the pulley In the retracted position (see illustration). 11 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 bell off the sprockets-Note that the crankshaft and camshaft must not be rotated whilst the belt Is removed. 12 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 doubt about its condition. If the engine ts undergoing an overhaul, renew the belt as a matter of course, regardless of Its apparent condition. The cost of a new belt is nothing compared with the cost of repairs, should the belt break in sen/ice. If signs of oil contamination are found, trace the source of the oil leak and rectify it. Wash down the engine timing belt area and alt related components, to remove all traces of oil.
Refitting 13 Before refitting, thoroughly clean the timing belt sprockets. Check that Ihe tensioner pulley rotates freely, without any sign of roughness. If necessary, renew the tensioner pulley as described In Section 5. 14 When refitting the new belt, make sure that the sprocket liming marks ore still In alignment and fit the belt so that the arrows on the belt point in the direction of engine rotation, and the lines of the belt coincide with the sprocket marks. 15 Engage the timing belt wilh the crankshaft sprocket first, then place it around the coolant pump sprocket and the camshaft sprocket (see illustration). Finally slip the bell around the tensioner pulley.
II
4.8 Removing the crankshaft pulley
16 Refease the tensioner nut and Insert the laws of a pair of right-angled clmilp pliers (or similar Into the two holes on the front face of the tensioner pulley. Rotate the pulley anticlockwise against the belt until the belt is quite taut. Check lhat the sprocket timing marks have not moved out of alignment. 17 Maintain the effort apptied to the tensioner pulley, then tighten the retaining nut. 18 Turn the crankshaft through two complete turns in the normal direction ot rotation and check that when the centre of (he longest run of the belt Is gripped between finger and thumb It can Just be twisted through 90°. 19 If the belt appears too be too slack or too fight, slacken the tensioner nut and repeat steps 16 to 18 until the correct tension is achieved. Caution: The above procedure serves only as a rough guide to setting the belt tension. The tension must be checked accurately by a Flat dealer using specialised checking equipment, at the earliest opportunity. 20 Refit the timing belt cover, the crankshaft pulley, auxiliary drivebelt(s>, spark plugs and the air cleaner/ducting. Adjust the tension of the auxiliary drivebelt(sl as described In Chapter 1A. 21 Refit the front wheel and lower the car to the ground.
5 Timing belt tensioner % and sprockets - removal, ^ Inspection and refitting ^
Timing beit tensioner
Removal 1 Firmly apply the handbrake, then jock up the front of the car and support it securely on axle stands (see Jacking and vehicle support). Remove the right-hand front roadwheel. 2 Remove the air cleaner and air ducting as described m Chapter 4A or 48, 3 Remove the auxiliary drivebeltfs) as descnbed In Chapter 1A. 4 Undo the three bolts and remove the crankshaft pulley from the sprocket, 5 Unbolt and remove the timing bolt cover. Note the bolt located at the bottom ot the cover, this can easily be overlooked.
4.10 Releasing the timing belt tensioner nut
4.15 Fitting the timing belt
6 Set the engine at TDC on No 1 cylinder as described In Section 2, 7 Loosen the nut on the timing belt tension* and move the tensioner pulley away from the belt (see Illustration), Keep the belt engaged with the sprockets using a cable-tie or string. 8 Completely unscrew the nut and slide Ihe tensioner off Ihe mounting stud. Inspection 9 Wipe the tensioner clean but do not use solvents that may contaminate the bearings. Spin the tensioner pulley on Its hub by hono. Stiff movement or excessive freeplay is w indication of severe wean the tensioner Is not a serviceable component, and should be renewed. Refitting 10 Slide the tensioner pulley over the mounting stud and fit the securing nut.
S.7 Timing bell tensioner retaining nut (arrowed) - shown with timing belt removed

2A*10 SOHC (8-valve) petrol engine in-car repair procedures
I To make o camshaft sprocket holding ; tool, obtain two lengths of steel strip I about 6 mm thick by 30 mm wide or ; similar, one €00 mm long, the other 200 mm long (all dimensions approximate). Bolt the two strips together to form a forked end, leaving the 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 fulcrums; these will engage with the cut-outs In the sprocket, and should protrude by about 30 mm
11 Check and adjust the tension of the timing tel with reference to Section 4. 12 Relit Ihe timing belt cover and tighten the bolts. 13 Relit the crankshaft pulley. 14 Refit and tension the auxiliary drivebelt(s)
as
described in Chapter 1. 15 Refil the air cleaner and air ducting as described in Chapter 4A or 48. 16 Refil the roadwheel and lower the vehicle
to the
ground.

Camshaft
sprocket
Removal 17 Remove the timing bell as described in Section 4. 16 The camshaft sprocket must now be held stationary while the retaining bolt is loosened. To
cto this,
make up a tool as follows and engage it
with the
holes
in
the sprocket (see Tool Tip). 19 Alternatively pass a rod through one of the holes in the camshaft sprocket to prevent it rotating. Position a pad of rag or a piece of
integral key
securing bolt and washer...
wood under the rod to avoid damaging the cylinder head. 20 Unscrew the bolt and slide the sprocket from the end of tho camshaft. Note the integral location key on the inner face of the sprocket (see illustrations). Inspection 21 With the sprocket removed, examine the camshaft oil seal for signs of leaking. If necessary, refer to Section 7 and renew it. 22 Check the sprocket teeth for damage. 23 Wipe clean the sprocket and camshaft mating surfaces. Refitting 24 Locate the sprocket on the end of the camshaft, then refit the bolt and washer and tighten to the specified torque while holding the camshaft stationary using the method described previously. 25 Refit the timing belt as described in Section 4.
Crankshaft sprocket
Removal 26 Remove the timing belt as described in Section 4. 27 Working beneath the engine, unbolt and remove the flywheel lower cover, then hold the flywheel stationary preferably using a toot which engages the flywheel starter ring gear (see Section 10). Alternatively have an assistant engage a wide-bladed screwdriver with the stader ring gear. 26 Unscrew the crankshaft sprocket retaining bolt and slide the sprocket off the end of the
^P
5.32 Tighten the crankshaft sprocket bolt to the specified torque
end of the camshaft Integral location key (arrowed)
crankshaft. The sprocket may have an integral location key on its inner face (see illustration), or a separate key which locates in a groove in the crankshaft nose may be fitted. Inspection 29 With the sprocket removed, examine the crankshaft oil seal for signs of leaking. If necessary, refer to Section 8 and renew it. 30 Check the sprocket teeth for damage. 31 Wipe clean the sprocket and crankshaft mating surfaces. Refitting 32 Slide the sprocket onto the crankshaft making sure it engages the integral key or separate key, then refit the bolt and washer and tighten the bolt to the specified torque while holding the crankshaft stationary using the method described in paragraph 27 (see illustration). 33 Refit the timing belt as described in Section 4.
6 Camshaft cover -removal and refitting
Removal 1 Remove the air cleaner assembly and inlet duct as described in Chapter 4A or 4B. 2 Progressively unscrew the mounting bolts from the top of the camshaft cover and lift off the cover • note the location of any supports on the bolts (see illustration). If it sticks, do
6.2 Removing the camshaft cover

2A*10 SOHC (8-valve) petrol engine in-car repair procedures
6.3 Camshaft cover gasket
not attempt to lover it ofl • instead free >t by working around the cover and lapping it lightly with a soft-faced mallet, 3 Recover the camshaft covor gasket {see Illustration). Inspect the gasket carefully. And renew It If damage or deterioration is evident. 4 Clean the mating surfaces of the cylinder head and camshaft cover thoroughly, removing all traces of oil and old gasket - take care to avoid damaging the surfaces as you do this.
Refitting 5 Locate a new gasket on the cylinder head and make sure it Is correctly seated. 6 Lower the cover onto the gasket making sure the gasket is not displaced. 7 Insert Ihe mounting bolts and tighten them progressively to the specified torque. 8 Refit the air cleaner assembly and inlet duct with reference to Chapter 4A or 48.
7 Camshaft oil seal • renewal I
1 Remove the timing beft and camshaft sprocket as described in Sections 4 and 5, 2 Using a suitable hooked Instrument, remove the oil seal from the cylinder head taking care not to damage the surface of (he camshaft. 3 Clean the seating in the cylinder head and the end of the camshaft. To prevent damage to the new olf seal as it is being fitted, wrap some adhesive tape around the end of the camshaft and lightly oil it.
4 Dip the new oil seal In oil then locate it over the camshaft making sure that the sealing lips are facing inwards, 5 Using a suitable tubular drift, drive the oil seal squarely Into the cylinder head. Remove the adhesive tape. 8 Refit the camshaft sprocket and liming belt wtth reference to Sections 5 and 4.
8 Crankshaft oil seals - ^ renewal S
Front (right-hand side) oil seal 1 The fronl oil seal is located in tho oil pump on the front of the crankshaft. Remove the timing belt as described in Section 4 and the crankshaft sprocket as described in Section 5. 2 Using a hooked instrument, remove the oil seal from the oil pump casing taking care not to damage the surface of the crankshaft. 3 Clean Ihe seating in the housing and the surface of the crankshaft. To prevent damage to the new oil seal as it is being fitted, wrap some adhesive tape around the end of the crankshaft and lightly oil it. 4 Dtp the new oil seal In oil then offer It up 1o the oil pump casing making sure that tho sealing lips are facing Inwards. G Using a suitable tubular drift, drive the oil seal squarely into the casing. Remove the adhesive tape. 6 Refit the crankshaft sprocket and timing belt with reference to Sections S and 4.
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 2D for details of removing the housing. 7 Remove the fiywheel/drlveplate as described in Section 10. 8 Using a suitable hooked instrument, remove the oil seal from the rear oil seat housing taking care not to damage the surface of Ihe crankshaft. 9 Clean the seating In the nousing and the surface of the crankshaft. Check the crankshaft for burrs which may damage the sealing lip of the new seal, and If necessary use a fine file to remove them,
10 Dip the new seal In clean engine oil and carefully locate it over the 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 fiywheet/drlvepiate with refer-ence to Section 10.
9 Cylinder head -removal and refitting I
i Removing the timing belt inner covers 9.12 Removing the cylinder head
Removal 1 Disconnect the battery negative termine! (refer to Disconnecting the battery In the Reference Section of this manual). 2 Drain the cooling system as described In Chapter 1A. then remove the air cleaner and ducting as described in Chapter 4A or 48. 3 Disconnect the accelerator cable and controls from the throttle housing. 4 Disconnect the fuel hoses. 5 Disconnect the coolant and vacuum hoses from the cylinder head and inlet manifold. 6 Disconnect all electrical leads noting their location. 7 Remove the Ignition colls with reference to Chapter 58. 8 Remove the timing belt as described in Section 4, then unbolt end remove the timing belt inner covers (see Illustration). 9 Unbolt and remove the Inlet manifold, complete with throttle housing. On MPI models unbolt the fuel rail. 10 Unbolt the exhaust manifold from th» cylinder head, and tie it to the front of tto engine compartment. If preferred remove the manifold completely by unbolting Ihe downpipe. Also disconnect iha downpipe bracket. 11 Unscrew the cylinder head bolts hall a turn at a time in the reverse order to thai shown In illustration 9.24b. When the bolts in free, remove them wtth their washers. 12 Lift the cylinder head from Ihe block (see Illustration), if It is stuck tight Insert pieces
of
wood Into the exhaust or Inlet ports, and use them as levers to rock the head off the block. On no account drive levers into the gasket joint, nor attempt to tap the head sideways,
as
It Is located on positioning dowels. 13 Remove and discard the cylinder heed gasket and the manifold gaskets. 14 The cylinder head can be dismantled after removing the camshaft and cam followers as described in Chapter 2D. 15 If the valves have been ground-in, the valve clearances will require adjusting, as described In Chapter 1A. This should be dons before the cylinder head is refitted to the engine.

2A*10 SOHC (8-valve) petrol engine in-car repair procedures
Preparation for refitting 16 The mating faces of the cylinder head and cylinder block must be perfectly clean 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 padicular care when cleaning the piston crowns as the soft aluminium alloy is easily damaged. Make sure that the carbon is not afowed to enter the oil and water passages -Ihs is particularly important for the lubrication
system, as
carbon could block the oil supply to
Ihe
engine's components. Using adhesive tape
and
paper, seal the water, oil and bolt holes in tf« cylinder block. To prevent carbon entering twgap between the pistons and bores, smear
a
iittte 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
ttie pistons
in the same way. 17 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 (xcassive, machining may be the only alternative to renewal. If warpage of the Cytodar head gasket surface is suspected, use a straight-edge to check it for distortion.
Refer
to Part 0 of this Chapter if necessary. 18 Check the condition of the cylinder head
MRS.
and particularly their threads, whenever
they are
removed. Wash the bolts In a suitable solvent, and wipe them dry. Check each bolt for any sign of visible wear or damage, renewing them if necessary.
Refitting 18 Before refitting Ihe 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. 20 Check that the camshaft and crankshaft sprocket timing marks are still aligned with tteir respective cylinder head and oil pump covtr marks as described in Section 2. 21 The new gasket should not be removed from its nylon cover until required for use. Fit
the
gasket dry, and make sure that the mating surfaces on the head and block are perfectly dean.
9.22a Place the cylinder head gasket on the cylinder block ... 22 Place the gasket on the cylinder block so that the word ALTO can be read from above (see illustrations). 23 Lower the cylinder head onto the block so that It locates on the positioning dowel. 24 The cylinder head bolt threads must be clean. Dip the bolts In engine oil. and allow them to drain for thirty minutes. Screw the bolls in finger-tight then working progressively and in the sequence shown, tighten all the cylinder head bolts to the Stage 1 torque 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 ihe 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 dunng this stage of tightening, to ensure accuracy (see Illustrations). 25 Refit the inlet manifold and throttle body using a new gasket (refer to Chapter 4A or 4B). 28 Refit the exhaust manifold using a new gasket. Tighten all nuts. Reconnect the exhaust downplpe bracket. 27 Refit the timing belt inner covers and tighten the bolls. 28 Refit the timing belt, and tension It as described in Section 4. Refit the timing belt outer cover. 29 Refit the ignition colls and camshaft cover. 30 Reconnect all hoses, electrical leads and controls referring the relevant Chapters of this manual. 31 Fit the air cleaner and ducting.
9.22b ... so that the ALTO marking can be read from above 32 Reconnect the battery then fill and bleed the cooling system as described in Chapter 1A.
10 Flywheel/driveplate • ^ removal, inspection
and
refitting ^
Removal 1 Remove the transmission as described in Chapter 7A or 7B. On manual transmission models also remove the clutch (Chapter 6). 2 Mark the position of the flywheel/driveplate with respect to the crankshaft using a dab of paint. Note thai on some models although there is only one location dowel on the flywheel/driveplate there are two holes in the eno of the crankshaft and it is therefore possible to locate Ihe flywheel 180n out. The flywheel/driveplate must now be held stationary while the bolts are loosened. A home-made locking tool may be fabricated from a piece of scrap metal and used to lock the ring gear. Bolt the tool to one of the transmission bellhousing mounting holes. 3 Unscrew then remove the mounting bolts then lift off the flywheel/driveplate. Recover the spacer plate on manual transmission models. Discard the fiywheet/drivepiate boils; new ones must be used on refitting.
Inspection
Manual transmission models 4 If the flywheel's clutch mating surface is deeply scored, cracked or otherwise damaged, the flywheel must be renewed.
JEaMKA. mar 9.24c Using an angle gauge to tighten the cylinder head bolts to their second and third stage torque settings
L

2A*10 SOHC (8-valve) petrol engine in-car repair procedures
require cutting with a sharp Knife to release
the sump.
Clean away all old gasket material. Refitting
5
Wwn refitting, a bead of RTV silicone nsiant gasket 3 mm in diameter should be applied lo the sump flange. Fit the sump, screw in tha fixing screws and tighten to the spscabed torque. Note the flange end fixing
nuts
(see illustrations).
6
'//ait one hour for the gasket compound to henjai before filling with engine oil. 7 Refit the flywheel housing cover plate and tohaust system front pipe.
8
lower the vehicle to the ground and fill the eng'rewith oil (see Chapter 1A). Check the oil
fevai
alter running the engine for a few minutes.

13 Oil
pump and pick-up tube - >>>
removal,
inspection and ^ refitting ^
Removal 1 Drain tho engine oil and remove the sump adsswibed in Section 12.
%
Unscrew and remove the oil filter cartridge .
(see
Chapter 1A|. 3 Remove the timing belt as described In
Section A.
4
Lock
the crankshaft against rotat>on either by tfacng a block of wood between a crankshaft wb and the inside of the crankcase, or by jjmning the flywheel starter ring gear with a
lutabfe
tool.
I3v8a Removing the oil pump pressure relief valve
12.5a Tightening a sump fixing screw
5 Unscrew and remove the crankshaft sprocket boll and take off the sprocket. If it is tight, use two screwdrivers to lever it off, or use a two or three-legged puller. 6 Unbolt and remove the oil pick-up/filter screen assembly. Note the sealing washer. 7 Extract the oil pump fixing bolts and withdraw the pump. Remove the gasket.
Inspection 8 The oil pump incorporates a pressure relief valve, which can be removed for examination by depressing the spring plunger and pulling out the keeper plate (see illustrations). 9 If 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 screwdriver (see illustration).
pressure relief valve
12.5b Sump fixing screw and flange end fixing nut
10 Check the clearance between the outer gear and the pump housing using feeler blades. Check the gear endtloat by placing a straightedge across the pump body, and checking the gap between the straight-edge and gear face (see illustrations). If the clearances are outside the specified tolerance, renew the oil pump complete. 11 If the pump is unworn, refit the rear cover plate and tighten the screws fully. 12 Apply air pressure from a tyre pump to the oil pump oil ducts, to clear any sludge or other material. Prime the pump by pouhng clean engine oil into its inlet duct, at the same time turning the oil pump inner gear with the fingers. 13 Lever out the oil seal and drive a new one squarely into the oil pump casing (see illustrations). Lubricate the oil seal lips.
13.9 Using an impact screwdriver to remove the oil pump rear cover pfate screws
13,19s Measuring oil pump outer gear-to- 13.10b Measuring oil pump gear endtloat pump housing clearance

2A*10 SOHC (8-valve) petrol engine in-car repair procedures
13.13b Using a socket to lit a new oil sea! to the oil pump
Refitting 14 Bolt the pump into position using a new joint gasket (see illustrations). Note that on© bolt Is longer than the others. 15 Bolt on the oil pick-up assembly using a
13.14a Using a new gasket. ..
new sealing washer. 16 Lock the crankshaft as described in paragraph 4, then fit the crankshaft sprocket and bghlen the bolt to the specified torque. 17 Fit the sumpaa described in Section 12. Screw on a new oil filter cartridge.
13.14b ... reftt the oil pump
18 Fit and tension the timing belt as described in Section 4. 19 Fill the engine with oil (see Chapter 1A>. 20 Run the engine for a few minutes, then check and top-up the oil level (see Weekly checks).
expert22 f
a http://rutracker.org

2A*10 SOHC (8-valve) petrol engine in-car repair procedures
Lubrication system Oil pump type By-rotor driven from front of crankshaft Outer rotor-io-houslng clearance 0.100 to 0.210 mm Axial clearance 0.025 to 0.070 mm
Torque wrench settings Nm itrf ft Camshaft driven gears 120 89 Camshaft sprocket 120 89 Crankshaft sprocket centre bolt: Stage
1
20 15 Stage 2 Angle-tighten a further 90® Cylinder head: Stage
1
30 22 Stage 2 Angle-tighten a further 90" Stage 3 Angle-tighten a further 90° Cylinder head extension to cylinder head 15 11 Engine mounting bolt: M10
x
1.25 59 44 M8 25 18 Engine mounting nut (MlOx 1.25) 60 44 Flywheel 44 32 Timing belt tensioner 25 18 Sump 10 7
1 General information
Using this Chapter Chapter 2 is divided into four Parts; A, B. C and O. Repair operations that can be carried out with the engine hi the vehicle are described in Part A. SOHC (8-valve) petrol engines. Part B, DOHC (16-valve) petrol engines and Pari C, dlesei engines. Part D covers the removal of the engine/transmission as a unit, and describes the engine dismantling and overhaul procedures. In Parts A, B and C, the assumption Is made that the engine is Installed In the vehicle, with all ancillaries connected. If the engine has been removed for overhaul, the preliminary dismantling information which precedes each operation may be ignored.
Engine description Throughout this Chapter, engines are identified by their capacities. A listing of all engines covered, together with their code letters, Is given in the Specifications. The engine covered in this Part of Chapter 2 is a water-cooled, double overhead camshaft, in-line four-cylinder unit, with cast iron cylinder block and aluminium-alloy cylinder head. The unit is mounted transversely at the front of the vehicle, with the transmission bolted to the left-hand side of the engine. The cylinder head houses the eight inlet and eight exhaust valves, which are closed by single coil springs, and which run in guides pressed Into the cylinder head. The two camshafts are housed in 8 cylinder head extension which is bolted to the top of the cylinder head. The exhaust camshaft is driven by a toothed timing belt and In turn drives the inlet camshaft via a pair of gears located at the left-hand end of the cylinder head extension.
The camshafts actuate the valves directly via self-adjusting hydraulic cam followers mounted in the cylinder head extension. The crankshaft is supported by five main bearings, and endfioat is controlled by a thrust bearing fitted to (he upper section of the centre main bearing. Engine coolanl is circulated by a pump, driven by the timing belt. 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 Ihe sump through a strainer, and then forced through an externally-mounted, replaceable screw-on filter. From there, It is distributed to the cylinder head and cylinder head extension, where it lubricates the camshaft journals and cam 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, to improve cooling.
Repair operations possible with the engine in the car The following work can be carried out with the engine in the car: a) Auxiliary drivebett - removal and refitting (refer to Chapter 1A) b) Oil pump and pick-up tube assembly -removal, Inspection and refitting c) Timing belt and covers • removal and refitting d) Timing belt tensioner and sprockets -removal and refitting e) Cylinder head - removal and refitting' f) Cylinder hoad extension - removal and refitting g) Camshaft and cam followers - removal and refitting h) Camshaft oil seal - renewal i) Crankshaft oil seals • renewal
f) Flywheel - removal, inspection and
refitting
k) Engine mountings - Inspection and
renews'
f) Sump • removal and refitting 'Cylinder head dismantling procedures are detailed In Chapter 2D. Note 1: It is possible to remove the
pistons
and connecting rods (after removing (to cylinder head and sump) without removing
tt*»
engine. However, this Is not recommended. Work of this nature is more easily and thoroughly completed with the engine on fix bench, as described in Chapter 20. Note
2x
Many of the procedures in this Ctopfer entail the use of numerous special tools. Whet possible, suitable alternatives are descnbei with details of their fabrication. Before starring any operations on the engine, read through
tto
entire procedure first to familiarise yourself
wft
the work involved, tools to be obtained mi new parts that may be necessary.
2 Engine assembly/ valve timing holes -genera! information
and
usage
Note: Do not attempt to rotate the angint whilst the camshafts are locked In position,
il
the engine is to be left in this state foratofi$ period of time. It Is a good idea to plect suitable warning notices inside the vehicle, and in the engine compartment. This wfl reduce the possibility of the engine being accidentally cranked on the starter motor, which is likely to cause damage with the locking tools In place. 1 To accurately set the valve timing for ell operations requiring removal and refitting of
the
timing belt, liming holes are drilled in ihe camshafts and cylinder head extension. Ihe holes are used In conjunction with camshaft locking tools and crankshaft positioning
rods w
lock the camshafts when all the pistons me positioned at the mid-point of their stroke. Ths

2B*3 DOHC (16-valve) petrol engine in-car repair procedures
2.2s Arrangement of Fiat special tools for setting the piston position and locking the camshafts
arrangement prevents the possibility of the vaivescontacting the pistons when refitting the cinder head or timing belt, and also ensures tet the correct valve timing can be obtained.
The design
of the engine is such that there are n> conventional timing marks on the crankshaft
er
camshaft sprockets to indicate the normal 70C position. Therefore, for any work on the lining belt, camshafls or cylinder head, the b&ng
and
positioning tools must be used.
2 The
special Fiat tools for setting the camshafts and pistons consist of two rods ttikh slide in sleeves that are screwed into
So
t and No 2 cylinder spark plug holes. The
rods are
pushed down to contact the pistons, ird the crankshaft is then turned until both tods protrude from their sleeves by the same enount. With the crankshaft correctly set,
ti»o
camshaft locking pins are used, one for tM inlet camshaft and one for the exhaust earretaft. The pins are screwed into holes on *ach »de of the cylinder head extension so M they engage with slots machined In (he
2.2b Fiat special tool for setting piston position...
camshafts. The arrangement of the Rat special tools are shown (see illustrations). The tool numbers are as follows: Camshaft locking toots Toot No 1860985000 Piston positioning tool Toot No 1860992000
2.2c ... and locking the camshafts
3 Although the special Fiat tools are relatively inexpensive and should be readily available from Flat dealers, it is possible to fabricate suitable alternatives, with the help of a local machine shop, as described below. Once the tools have been made up, their usage Is described In the relevant Sections of this Chapter where the tools are required. Camshaft locking tool fabrication 4 Remove the air cleaner, inlet air duct and resonator as descnbed in Chapter 4B. 5 Unscrew the sealing plug from the front face of the cylinder head extension. 6 Using the sealing plug as a pattern, obtain a length of threaded dowel rod or two suitable bolts to screw into the sealing plug hole. With the help of a machine shop or engineering works, make up the camshaft locking toots by having the dowel rod or bolts machined to the dimensions shown (see illustrations). Note that two will be needed, one for each camshaft.
Suitabt* roll pin (or titling /
ramoviitg
tool
-J 10 h -4 h
AT —
T
—
2,6a To make an alternative camshaft locking tool... 2.6b ... have suitable dowel rods or bolts machined to the dimensions shown

2B*4 DOHC (16-valve) petrol engine in-car repair procedures
4.8 Undo three bolts and romove tho crankshaft pulley from the sprocket
Crankshaft setting toot fabrication 7 To make Ihe crankshafl setting tools, four old spark plugs will be required, together with four lengths of dowel rod. The length of each dowel rod is not critical, bul It must be long enough to protrude about 100 mm above the top of the cylinder head extension when resting on top of a piston located half way down its bore. What is critical, however, is that all four do wo I rods must be exactly the same length. 8 Break off the ceramic upper section of each plug and remove the centre electrode and earth tip. The easiest way to do this is to mount each spark plug in a vice (attar removing the ceramic uppor plug section) and drill a hole down through ihe centre of the plug. The diameter of Ihe drill bit should be the same as Ihe diameter of Ihe dowol rod to be used. When finished you should have four spark plug bodies and four equal length dowel rods which will slide through the centre of the spark plugs.
3 Cylinder compression test
1 When engine performance is down, or it misfiring occurs which cannot be attnbuted to the Ignition or fuel systems, 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 bofore any other symptoms become apparent.
4.10 Undo the upper timing cover upper retaining bolt, and the rear retaining boll
4.9 Undo the retaining bolt in the centre of the lower timing cover
2 The engine must be fully warmed-up to normal operxrtrfjg temperature, the battery must be fully charged, and all the spark plugs muse be removed (Chapter 1A>. The aid of an assistant wilt also be required. 3 Disable the ignition system by discon-necting the LT wiring plugs to the Ignition coils. 4 Fit a compression tester to the No t cylinder spark plug hole • the type of tester which screws into the plug thread is to be preferred. 5 Have the assistant hold the throttle wide open, and crank the engine on the starter motor; after one or two revolutions, the compression pressure should build up to a maximum figure, and then stabilise. Record the h.ghest reading obtained 6 Repeat the test on the remaining cylinders, recording Ihe pressure in each. 7 All cylinders should produce very similar pressures; any excessive difference indicates Ihe existence of a fault. Note that the compression should build up quickly in a healthy engine; low compression on (he 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 head could also be tho cause). 6 If the pressure in any cylinder is very low, carry out the following test to isolate the cause. Introduce a teaspoonful of dean oil into that cylinder through its spark plug hole and repeal the lest. 9 If the addition of oil temporarily improves the compression pressure, this indicates that bore or piston wear is responsible for the pressure loss. No improvement suggests that leaking or burnt valves, or a blown head gasket, may be to blame. 10 A low reading from two adjacent cylinders is almost certainly due to the head gasket having blown between Ihem; the presence of coolant in the engine oil will confirm this. 11 If one cylinder is about 20 percent lower than the others and the engine has a slightly rough idle, a worn camshaft lobe could be the cause. 12 On completion of the test, refit the spark plugs and reconnect the ignition LT wiring plug.
4 Timing belt and covers -removal and refitting §
General information 1 The luncUon of the timing belt Is to drive the camshafts and coolant pump. Should the bell slip or creak in service, the valve timing will be disturbed and piston-to-valve contact wiu occur, resulting in serious engine damage. 2 The timing belt should be renewed at the specified Intervals (see Chapter 1A), or earlier If It is contaminated with oil, or if it is at all noisy In operation (a scraping noise due to uneven wear}. 3 If the timing belt is being removed, it is
a
wise precaution to check the condition of the coolam pump at the same time (oheck for signs of coolant leakage). This may avoid the need to remove the timing belt again at a later stage, should the coolant pump fail. 4 Before carrying out this procedure, it will be necessary to obtain or fabricate suitable camshaft locking tools and piston positioning tools as described in Section 2. The procedures contained In this Section depict the use of the home-made alternative tools described in Section 2. which were fabricated In the Haynes workshop. If the manufacturers tools are being used instead, the procedures are virtually identical. Oo not attempt to remove the timing bell unless the special totfs or their alternatives are available.
Removal 5 Disconnect the battery negative terminal (refer to Disconnecting the battery in the Reference Section of Ihis manual). 6 Remove the auxiliary drivebelt(s) as described In Chapter 1A. 7 Remove the air cleaner, Inlet air duct and resonator as desenbed In Chapter 4B. 8 Undo the three bolts and remove the crankshaft pulley from the sprocket (see illustration). 9 Undo the retaining bolt In the centre of the lower liming cover (see illustration). 10 Undo tho uppor timing cover upper retaining bolt, and the rear retaining bolt located above the alternator (see illustration). 11 Release the crankshaft TDC sensor wiring from the clip on the upper timing cover, then withdraw the cover slightly and slide Ihe wiring plug and socket from the liming cover slot (see illustrations). 12 Release the TDC sensor wiring from the periphery ol the upper and fower timing covers and remove both covers (see Illustrations). 13 Free the accelerator inner cable from the throttle cam, remove the outer cable spring dip, then pull the outer cable out from its mounting bracket rubber grommet. 14 From the side of the throttle body, disconnect the wiring connectors from the

2B*5 DOHC (16-valve) petrol engine in-car repair procedures
4.11a Release the crankshaft TDC sensor wiring from the clip on the upper timing cover... throttle potentiometer and the Idle control stepper motor. Disconnect the coolant temperature sensor wiring connector located
in
the inlet manifold below the throttle body,
end
disconnect the brake servo vacuum hose. 15 Disconnect the wiring connectors for the fuel injector harness and the intake air temperature/pressure sensor, then fcconnect the fuel pressure regulator vacuum hose and the EVAP purge valve hose. 18 Undo the two bolts securing the plastic mlet manifold upper section to the lower section. Release the spark plug HT lead from the location groove in the manifold upper wctton, then lift the upper section, complete
»ith
throttle body, off the engine. Recover the 0-rngs from the manifold ports. 17 Unscrew the two bolts securing the fuel
4£1a Screw the spark plug bodies of the homo-made piston positioning tools into each spark plug hole ...
4.21b ... place a suitable washer or similar into the recess to keep the dowel rod vertical...
4.11b ... then slide the wiring plug and socket from the timing cover slot
rail assembly to the inlet manifold lower section, then carefully pull the Injectors from the manifold. Lift the fuel rail and Injector assembly, with fuel hoses still connected, and position it to one side. 16 Undo the bolts securing the engine management ECU mounting brackets to the body and move the ECU to one side without disconnecting the wiring connector. 19 Remove the spark plugs as described in Chapter 1A. 20 Unscrew the two sealing plugs from the front and rear of the cylinder head extension to enable the camshaft locking tools to be inserted. 21 Screw the spark plug bodies of the home-made piston positioning tools into each spark plug hole and insert the dowel rods into each body. To keep the dowel rods vertical, locate a suitable washer or similar over Ihe rod and into the recess at the top of the spark plug hole. In the photos shown here, an old valve stem oil seal housing was used but anything similar will suffice (see illustrations). 22 Using a socket on the crankshaft sprocket centre bolt, turn the crankshaft in the normal direction of rotation until all four dowel rods are protruding from the top of the cylinder head extension by the same amount. As the engine is turned, two of the rods will move up and two will move down until the position is reached where they are all at the same hoight. The best way to check this is to place a straight edge along the top of the rods and turn the crankshafl very slowly until the
4.21c ... then insert the dowel rods
4.12b ... and lower timing covers
straight edge contacts all four rods (see illustration). 23 When all four rods are at the same height, all the pistons will be at the mid-point of their stroke. Using a screwdriver or similar inserted into the front timing hole in the cylinder head extension, check that the timing slot in the exhaust camshaft is approximately aligned with the liming hole. If the camshaft slot cannot be felt, turn the crankshaft through one complete revolution and realign the dowel rods using the straight edge. Check again for the camshaft slot. Note that although the pistons can be at the mid-point of their stroke twice for each cycle of the engine, the camshaft slots will only be positioned correctly once per cycle. 24 With the pistons correctly set, it should now be possible to screw in the camshaft
4.22 Place a straight edge along the top of the rods and turn the crankshaft until the straight edge contacts ail four rods