1999 FIAT PUNTO flywheel

2A«1
Chapter 2 Part A:
SOHC (8-valve) petrol
engine in-car repair procedures
Contents
Auxiliary drivebelts • removal and refitting See Chapter 1A Gamstaft cover - removal and refitting 6 Camshaft oil seal - renewal 7 Camshaft • removal and refitting See Chapter 20 Crankshaft oil seals - renewal 8 Cylinder compression test 3 Cylinder head - dismantling and overhaul See Chapter 20 Cylinder head - remove] and refitting 9 Engine mountings - Inspection and renewal 11 Engine oil and filter • renewal See Chapter 1A
Degrees of difficulty
Engine oil level check See Weekiy checks Flywheel/driveplate • removal, inspection and refitting 10 General Information 1 Location of TOC on No 1 cylinder 2 Oil pump and pick-up tube - removal, inspection and refitting 13 Sump • removal and refitting 12 Timing belt and covers • removal and refitting .. 4 Timing belt tensioner and sprockets - removal, inspection and refitting 5 Vafve clearance check and adjustment See Chapter 1A
Easy, suitable (or twics with little |g experience ^
Fairty easy, suitable jk for beginner with & some experience ^
Fatrty difficult, ^ suitable for competent ^ CKYmechanic ^
Difficult, suitable for ^ experienced DIY « mechanic ^
Veiy difficult, ^ aiitabte for expert DIY « or professional
Specifications
General Engine code:' 1108 cc engine (55 models): Up to May 1997 176.A6.000 May 1d97 onwards • . 176.B2.000 1242 cc engine (60 models): Up to May 1997 176.B1.000 May 1997 onward 176.B4.000 1242 cc engine (75 modete) 176.A8.000
•Note:
See Vehicle Identification for the location of code marking on the engine. 8cre: 11O0OC engine 70.0 mm 1242 cc engine 70.8 mm Stroke: 1108 cc engine 72.0 mm 1242 cc engine 78.86 mm Compression ratio: 1108 cc engine 9.6:1 1242 cc engine with single-point injection 9.6:1 1242 cc engine with multi-point injection 9.8:1 Rrlng order 1-3-4-2
No 1
cylinder location Timing belt end of engine
TnUng
belt tension See text
Lubrication system
Oil
pump type By-rotor driven from front of crankshaft Outer rotor-to-housing clearance 0.080to0.186mm
Axial
clearance 0.025 to 0.056 mm

2A*10 SOHC (8-valve) petrol engine in-car repair procedures
Torque wrench settings Nm
IM
ft Camshaft cover 8 6 Camshaft sprocket 70 52 Cylinder head; Stage 1 30 22 Stage 2 Angle-lighten a further 90° Siege 3 Angle-tighten a further 90B Crankshaft sprocket centre bott 100 74 Engine mounting bolt: M10X1.25 69 44 MB 25 18 Engine mounting nut (M10x 1.25) 60 44 Flywheet/driveplate 44 32 Sump 10 7 Timing belt tensJoner 28 21
1 General information
Using this Chapter Chapter 2 is divided Into four Parts: A. 8. C and D. Repair operations that can be carried out with the engine in the vehicle are described in Part A. SOHC (8-valve) petrol engines, Part B. DOHC (18-valve) petrol engines and Part C, diesel engines. Part 0 covers the removal of the engine/transmission as a unit, and describes the engine dismantling and overhaul procedures. In Parts A, 9 and C, the assumption Is made lhat the engine is Installed in the vehicle, with sll 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 engines covered In this Part of Chapter 2 are water-cooled, single overhead camshaft, in-line four-cylinder units, with cast Iron cylinder Mocks and aluminium-alloy cylinder heads. All are mounted transversely at the front ot 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 and runs In three bearings. It also houses the inlet and exhaust valves, which are closed by single coil springs, and which run in guides pressed Into the cylinder head. The camshaft actuates the vatves directly via cam followers mounted in the cylinder head. Adjustment of the valve clearances is by means of shims located on top of the followers. The cylinder head contains Integral oitways which supply and lubricate the tappets. The crankshafl Is supported by five main bearings, and endftoat is controlled by a thrust bearing fitted to the upper section of the centre main bearing.
Engine coolant is circulated by 8 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 ihe 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 It lubricates the camshaft journals and tappets, and also to the crankcase, where il lubricates the main bearings, connecting rod big and smell-ends, gudgeon pins and cylinder bores. On 1242 cc engines, oil jets are fitted lo 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) Compression pressure - testing b) Auxiliary drivebelt - removal and refitting (refer to Chapter 1A) c) Vatve clearances - checking and adjustment (refer to Chapter I A) d) Camshaft cover - removal and refitting e) Timing belt and covens - removal and refitting f) Timing belt tensioner and sprockets -removal and refitting g) Cylinder head - removal and refitting' h) Camshaft and cam followers • removal and refitting' t) Camshaft oil seal - renews/ j) Crankshaft oil seals - renewal k) Flywheel/dnvepfate • removal, inspection and refitting l) Engine mountings - inspection and renewal m)Sump - removal and refitting n) Oil pump and pick-up tube assembly
•
removai. inspection and refitting *Cylinder head dismantling procedures are detailed In Chapter SO, with details of camshaft and cam follower removal. Note: It is possible to remove the pistons and connecting rods (after removing the cylinder head 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 the bench, as described In Chapter 2D.
2 Location of
TDC
on % No
1
cylinder
General Information 1 The camshaft Is driven by the crankshaft, by means of sprockets and a timing belt. Both sprockets rotate In phase with each other and this provides the correct valve timing as the engine rotates. When (he liming belt is removed during servioing or repair, it Is possible for the camshaft and crankshaft to rotate Independently of each other and the correct valve timing Is then lost. 2 The design of the engines covered In this Chapter are such lhat potentially damaging piston-to-valve contact may occur if the camshaft is rotated when any of the pistons are stationary at, or near, the top of their stroke. 3 For this reason it is important lhat Ihe correct phasing between the camshaft and crankshaft is preserved whilst the timing belt Is off the engine. This is achieved by setting the engine In a reference position (known as Top Dead Centre or TDC) before the timing belt Is removed and then preventing the camshaft and crankshaft from rotating until the belt is refitted. Similarly, if ths engine has been dismantled for overhaul, the engine can be set to TOC during reassembly to ensure that Ihe correct shaft phasing is restored. 4 TDC is the highest point In the cylinder that each piston reaches as the crankshaft turns. Each piston reaches TDC at Ihe end of the compression stroke and again at the end of the exhaust stroke. However, for the purpose of timing the ongine. TDC refers to the position of No 1 piston at the end of Its compression stroke. On ail engines In this manual, No 1 piston (and cylinder) Is at the timing belt end of the engine. 5 The camshaft sprocket Is equipped with a marking which, when aligned with a reference marking on the cylinder head, indicates that the camshaft is correctly positioned for cyl-inder No 1 al TDC on its compression stroke.

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
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
10.10 Tighten the flywheel bolt to the specified torque However, it may be possible lo have it surface*ground; seek (he advice of a Rat dealer or engine reconditioning specialist, 5 If Ihe ring gear is badly worn or has missing teeth, the flywheel must be renewed. Automatic transmission models 6 Check the driveplate for signs of damage and renew it if necessary. If the ring gear is badly worn or has missing teeth, the driveplate must be renewed.
Refitting 7 Clean the mating surfaces of the flywheel/ drivoplate and crankshoft. Remove any remaining locking compound from the threads of the crankshaft holes, using the correct-size tap. if available.
ft a suitable tap fs not . # | available, cut two slots down jHlNTI
toe
threads of ono of the old bolts with a hacksaw, and use the bolt to remove the locking compound from the throads.
8 If the new retaining bolts are not supplied with their threads already pre-coated, apply a suitable thread-locking compound to the threads of each bolt. 9 Offer up the fiywhee'/drlveplate lo the crankshaft, using the alignment marks made during removal, and fit the new retaining bolts (together with the spacer plate on manual transmission models), 10 Lock the flywheel/dnveplate using Ihe method employed on dismantling, and tighten
the retaining bolts to the specified torque (see illustration), 11 Refit the clutch on manual transmission models as described in Chapter 6. 12 Relit the transmission as described In Chapter 7A or 78.
11 Engine mountings • inspection and renewal
inspection 1 Firmly apply the handbrake, then jack up the front of the car and support it securely on axle stands (see Jacking and vehicle support). 2 Check Ihe mounting rubbers to see if they are cracked, hardened or separated from the metal at any point; renew the mounting if any such damage or deterioration is evident. 3 Check that all the mounting's fasteners are securely tightened; use a torque wrench to check II possible. 4 Using a large screwdriver or a crowbar, check for wear In the mounting by carefuliy levering against It to check for free play. Where this is not possible enlist the
aid
of
an
assistant to move the engina/transmission back
and
forth, or from s»de to side, while you watch the mounting. While some free play rs to bo expected even from new components, excessive wear
should
be obvious. If excessive free play is found, check first that the fasteners are correctly secured, then renew any worn components as described below.
Renewal Right-hand mounting 5 Firmly apply the handbrake, then jack up the front of the car and support it securely on axle stands (see Jacking and vehicle support). 8 Place a trolley jack beneath the right-hand side of Ihe engine, with a block of wood on the jack head. Raise the jack until it is supporting the weight of the engine. 7 Unscrew the nut securing the engine bracket to the mounting. 8 Lower the engine slightly then unboll the mounting from the body. 9 Locate the new mounting on the body, insert the bolts and tighten to the specified torque.
10 Raise tne engine and locate the bracket on the mounting. Refit tho nut and tighten lo the specified torque. 11 Remove the trolley jack and lower the vehicle to the ground. Left-hand mounting 12 Firmly apply the handbrake, then jack up the front of the car and support it securely on axle stands (see Jacking and vehicle support) 13 Place a trolley |sck beneath the transmission, with a block of wood on the jack head. Raise the jack until it is supporting tne weight of the engine/transmission. 14 Unscrew Ihe bolts securing the left-hand mounting to tho body. 15 Unscrew the nut securing ihe mounting to the transmission bracket and recover the washers. 16 Lower the transmission sufficiently to remove the mounting from the transmission bracket. 17 Locate the new mounting In the trans-mission bracket and refit the nut and washers. Tighten the nut to the specified torque. 18 Raise the engine and refit the mounting-to-body bolts. Tighten the bolts to the specified torque. 19 Remove the Irolloy jack and lower the vehicle lo the ground. Rear mounting 20 Firmly apply the handbrake, then Jack up the front of the car and support It securely on axle stands (see Jacking and vehicle support). 21 Working beneath Ihe vehicle, unscrew Ihe bolts secunng the rear engine mounting to the underbody. 22 Temporarily support the weight of the engine/transmission using a trolley jack. 23 Unbolt the rear mounting assembly from Ihe transmission and withdraw from under the vehicle. 24 Unscrew the bolt and separate Ihe bracket from tlve mounting. 28 Fitting the new mounting Is a reversal of the removal procedure.
12 Sump -removal and refitting
12.2 Removing the flywheel housing cover plate 12.4 Removing the sump
Removal 1 Firmly apply the handbrake, then jack up the front of the car and support it securely on axle stands (see Jacking and vehicle support). Drain the engine oil as described in Chapter 1 A. 2 Unbolt and remove the cover plate from the lower pari of the llywheel housing (see illustration). 3 Refer to Chapter 4D and unbolt the exhaust Iront pipe from Ihe manifold. Undo Ihe support bracket fastenings and lower the front pipe clear of the sump. 4 Unscrew the sump securing screws and nuts and pull the sump downwards to remove it (see Illustration). The joint sealant will

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

2B»1
Chapter 2 Part B:
DOHC (16-valve) petrol
engine in-car repair procedures
Contents
Auxiliary drlvebelts - removal and refitting See Chapter 1A Camshaft oil seal - renewal 6 Camshafts and cam followers - removal, inspection and refitting .. 9 Crankshaft oil seals • renewal 7 Cylinder compression test 3 Cylinder head - dismantling and overhaul See Chapter 2D Cylinder head • removal and refitting 10 Cylinder head extension • removal and refitting 8 Engine assembly/Valve timing holes - general information and usage 2
Engine mountings - inspection and renewal 12 Engine oil and filter - renewal See Chapter 1A Engine oil level - check See Weekly checks Flywheel - removal, Inspection and refitting 11 General Information 1 Oil pump and pick-up tube - removal, inspection and refitting 14 Sump - removal and refitting 13 Timing belt and covers - removal and refitting 4 Timing belt tensioner and sprockets • removal and refitting 5
Degrees of difficulty

Easy,
sitable
for
J; Fairly
easy,
suitable Fairtydifflcutt, ^
Difficult,
aitabtefcr Very
difficult,
^ nwice
wim
(ttls for beginner with £
suitable
for competent KYmechanic ^ experienced DIY > suitable
for
expert DIY« experience
some
experience £
suitable
for competent KYmechanic ^ mechanic > or professional ^
Specifications
General Engine code* 176.09.000 •Note: See Vehicle Identification for the location of code marking on the engine. Bore 70.8 mm Stroke 78.86 mm Capacity 1242 cc Compression ratio 10.2:1 Firing order 1-3-4-2 No
1
cylinder location Timing belt end of engine Timing belt tension See text
Camshaft Orlve Toothed belt
No
of bearings 3 Camshaft bearing journal diameters: Ho
1
bearing 35.000 to 35.015 mm
Mo
2 bearing 48.000 to 48.015 mm No 3 bearing 49.000 to 49.015 mm Camshaft bearing Journal running clearance 0.030 to 0.070 mm Camshaft endfloat 0.15 to 0.34 mm
Cylinder head extension Camshaft bearing diamelers: No
1
bearing 35.045 to 35.070 mm No 2 bearing 48,045 to 48.070 mm No 3 bearing 49.045 to 49.070 mm
Cam
follower (tappet) type Hydraulic
Cam
follower (tappet) diameter 28.353 to 28.370 mm
Cam
follower (tappet) bore diameter in cylinder head extension 28.400 to 28.421 mm
Cam
follower (tappet) running clearance 0.046 to
0.051
mm

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