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
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*7 DOHC (16-valve) petrol engine in-car repair procedures
35 Slacken the tensioner pulley retaining nut and reposition the tensioner to align the
mobile
indicator with the fixed reference mark
on the
pulley face (see illustration). Hold the
pdley in
this position and tighten the retaining
nut to the
specified torque. 36 Turn the crankshaft through a further two complete turns In the normal direction of rotation. Check that the timing is correct by alining Ihe piston positioning tools and
camshaft
locking tools as described previously. 37 When all is correct, remove the setting rri
locking
tools and refit the sealing plugs to 1ft© cylinder head extension, using new 0-
nr^s if
necessary. Tighten the plugs securely. 38 Refit the spark plugs as described in Chapter 1A. 39 Refit Ihe ECU and secure with Ihe mooning bolts. 40
Renew the
injector O-ring seals, smear them Kith
8 little
Vaseline then locate the injectors and tef rail onto the inlet manifold lower section.
Saute Ihe fuel rail
with the two retaining bolts. 41 Relit the inlet manifold upper section using new sealing O-rlngs If necessary and
sectre
with the two bolts. 42 Reconnect the wiring connectors for the tot injector harness and the intake air temp-erature/pressure sensor, then connect the fuel pressure regulator vacuum hose and tha
EVAP
purge valve hose. 43 Reconnect the wiring connectors for the ihrottls potentiometer, idle control stepper motor and coolant temperature sensor. Reconnect the brake servo vacuum hose. 44 Refit and adjust the accelerator cable as described in Chapter 4B. 46 Refit the upper and lower timing belt
covers
together with the TDC sensor wiring. 46 Refit the crankshaft pulley and tighten the
three
retaining bolts securely. 47 Refit the air cleaner. Inlet air duct and resonator as described in Chapter 4B. 48
Refit
tha auxiliary drivebelt(s) as described i/t Chapter 1A, then reconnect the battery
S Timing belt tensioner
and
sprockets -
removal
and refitting
Timing
belt tensioner
Removal I
Remove
the timing belt as described in
Section
4. 1 Completely unscrew the tensioner nut and Wiethe tensioner off the mounting stud-Inspection
3 Wipe
the tensioner clean but do not use Kfrents that may contaminate the bearings.
Spin
the tensioner pulley on its hub by hand.
Sfcfl
movement or excessive freeplay is an rcfceticn of severe wear: the tensioner is not 3 serviceable component, and should be nnewsd.
4.33 Holding the camshaft sprocket with the tool described previously while tightening the sprocket bolt Refitting 4 Slide the tensioner pulley over the mounting stud and fit the securing nut. 5 Refit the timing belt as described in Section 4. Camshaft sprocket Removal 6 Remove the timing belt as described in Section 4. 7 Unscrew the bolt and slide the sprocket from the end of the camshaft. Inspection 8 With the sprocket removed, examine the camshaft oil seal for signs of leaking. If necessary, refer to Section 6 and renew it. 9 Check the sprocket teeth for damage. 10 Wipe clean the sprocket and camshaft mating surfaces. Refitting 11 Locate the sprocket on the end of the camshaft, then refit the retaining boll finger tight only at this stage. 12 Refit the timing belt as described in Section 4.
Crankshaft sprocket Removal 13 Remove the timing bell as described In Section 4. 14 Working beneath the engine, unbolt and remove the flywheel lower cover, then hold the flywheel stationary preferably using a tool which engages the flywheel starter ring
<
Alternatively have an assistant engage a wide-bladed screwdriver with the starter ring gear. 15 Unscrew the crankshaft sprocket retaining bolt and slide the sprocket off the end of the crankshaft. The sprocket may have an integral location key on its inner face, or a separate key which locates In a groove in the crankshaft nose may be fitted. Inspection 16 With the sprocket removed, examine the crankshaft oil seal for signs of leaking. If necessary, refer to Section 7 and renew it. 17 Check the sprocket teeth for damage. 18 Wipe clean the sprocket and crankshaft mating surfaces. Refitting 19 Slide the sprocket onto the crankshaft making sure
11
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 14. 20 Refit the timing belt as described in Section 4.
6 Camshaft
oil
seal -renewal
1 Remove the timing belt and camshaft sprocket as described in Sections 4 and 5. 2 Punch or drill a small hole in the oil seal. Screw a self-tapping screw into the hole, and pull on the screws with pliers to extract the seal. 3 Clean the seal housing, and polish off any burrs or raised edges, which may have caused the seal to fall in the first place. 4 Lubricate the lips of the new seal with clean engine oil, and drive it into position until It seats on its locating shoulder. Use a suitable tubular drift, such as a socket, which bears only on the hard outer edge of the seal. Take care nof to damage the seal lips during fitting. Note that the Seal lips should face inwards. 5 Refit the camshaft sprocket and timing belt as described in Sections 5 and 4.
7 Crankshaft oil seats -renewal I
4.35 Position the tensioner so that the mobile Indicator (1) is aligned with the fixed reference mark (2)
Front (right-hand side) oil seal 1 The front oil seal is located in the 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 the 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.
2C«1
Chapter 2 PartC:
Diesel engine in-car repair procedures
Contents
Auxiliary drivebelts - removal and refitting See Chapter 1B Camshaft cover - removal and refitting 6 Camshaft oil seal - renewal 7 Camshaft - removal and refitting See Chapter 20 Crankshaft oil seats - renewal 8 Cylinder compression test « 3 Cylinder head - dismantling and overhaul See Chapter 20 Cylinder head - removal and refitting 9 Engine mountings - inspection and renewal 11 Engine oil and fitter - renewal See Chapter 18 Engine oil level check See Weekly checks
Degrees of difficulty
Flywheel * removal, inspection and refitting 10 General information 1 Location of TDC on No 1 cylinder 2 Oil cooler - removal and refitting 14 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 Valve clearance check and adjustment See Chapter 1B
Easy,
suitable for novice
with Irttle
|| experience g^
FaMy
eesy,
suitable ^
forbeglnnerwilti
some experience ^
Falrtydfficult, ^ suitable
for
competent DIYmechanic ^
Difficult, suitable
for & experienced DIY mechanic ^
Very
difficult,
^ suitable
for
expert
DfY
jR or professional ^
Specifications
General Engine code:' 1698 cc non-turbo engine 176.B3.000 1698 cc turbo engine: Up to 1997 t76.A3.00aor176.A5.000 1997 onward 176.A3.000or176.B7.000 •Note: See Vehicle Identification for the location of the code marking on the engine. Bore 82.6 mm Stroke 79.2 mm Compression ratio: Non-turbo engine 20.5:1 Turbo engine 19:1 Firing order 1-3-4-2
No 1
cylinder location Timing belt end of engine Titling belt tension See text
Lubrication system Oi pump type By-rotor driven from front of crankshaft Outer rotor-to-houslng clearance 0.080 to 0.186 mm Axial clearance 0.025 to 0.056 mm
Torque wrench settings Nm ibf ft Camshaft cover 10 7 Camshaft sprocket 11B 87 Crankshaft sprocket centre bolt 190 140 Cylinder head: Stage 1 50 37 Stage 2 100 74 StageS Angle-tighten a furtfier 90" Stage 4 Angle-tighten a further 90° CySnder head front bolts 30 22 Flywheel 142 105
Fuel
injection pump sprocket 49 36 Inlet and exhaust manifolds 25 18 Sump 10 7 Timing belt tensioner and idler 44 32
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
2C*2 Diesel engine in-car repair procedures
10.2 Locking the flywheel using a homo* made tool
10 Flywheel - £ removal, inspection § and refitting ^
Removal 1 Remove the transmission and clutch as described in Chapter 7A and 6, 2 Lock the tlywheei in position using a home-made locking tool, fabricated from a piece of scrap metal. Boll it to one of the transmission belihousing mounting holes (see illustration). Mark the position of the flywheel with respect to the crankshaft using a dab of paint. Note that although there is only one location dowel on the flywheel, there are two holes In the end ol the crankshaft and it Is therefore possible to locate tne flywheel 180v out resulting in the timing mark being In Ihe incorrect position. 3 Unscrew and remove the flywheol mounting bolts then lift olf the llywheel. Recover the spacer piate (see illustrations). Discard the flywheol retaining bolts: new ones must be used on refitting,
Inspection 4 If the flywheel's clutch mating surface >s deeply scored, cracked or otherwise damaged, the flywhoel must be renewed. However, H may be possible to have It surface-ground: seek the advice of a Fiat dealer or engine reconditioning specialist, 5 If the ring gear Is bsdly worn or has missing teeth, the flywheel must be renewed.
Refitting 6 Clean the mating surfaces of the flywheel and crankshaft. Remove any remaining locking compound from the threads of the crankshaft holes, using the correct-size tap, if available.
HBTiffSrl If a suitable tap Is not
Wijlilfil
available, cut two slots down HlNTi threads of one of the old 1 J flywheel bolts with a hacksaw, and use the bolt to removo the locking compound form tho threads.
7 If the now flywheel retaining bous are not
10.8a Location dowel on the flywheel
supplied with their threads already pre* coated, apply a suitable thread-locking compound to the threads of each bolt. 8 Otter up the flywheel to the crankshaft, using the abgnment marks made during removal, and fit the new retaining oolts together with the spacer plate (see Illustrations). 9 Lock the flywheel using Ihe method employed on dismantling, and tighten the retaining bolts to the specified torque. 10 Refit the clutch as described in Chapter 6. Remove the locking tool and refit the transmission as described in Chapter 7A,
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 the mounting rubbers to see if they are cracked, hardened or separated from the metal ai any point; renew Ihe mounting if any such damage or deterioration is evident. 3 Check that all the mounting's fasteners are securely tightened, 4 Using a large screwdriver or a crowbar, check for wear In the mounting by carefully levering against il to check for free ploy. Where this is not possible enlist the aid of an assistant to move the onglno/transmission back and forlh. or from side lo side, while you watch the mounting While some free play is to be
10.8b Inserting tho flywheel bolts
expected even from new components, axcessive wear should be obvious. II 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 If not already done, firmly apply the handbrake, then jack up the front ot tho car and support it securely on axle stands (see Jacking and vohicle support), 6 Place a trolley lack beneath the right-hand side of the engine, with a block of wood on Ihe jack head. Raise the jack until it is supporting the weight of the engine. 7 Unscrew the bolts securing the nght-hand mounting to the body (see illustration). 8 Unscrew the special long nut securing the mounting to Ihe engine and recover the washers.
11.7 Right-hand engine mounting viewed from below
Apply a smear of clean engine oil to the gudgeon pin. Slide it Into the piston and through the connecting rod small-end. Check that the piston pivots freely on the rod. then secure the gudgeon pin in position with two new circlips. Ensure that each circlip is correctly located In Its groove in the piston.
Refitting and big-end bearing running ciearance check 27 Prior to refitting the piston/connecting rod assemblies, it Is recommended that the big-end bearing running clearance is checked as follows. Big-end bearing running clearance check 28 Clean the backs of the bearing shells, and the bearing locations in both the connecting rod and bearing cap. 29 Press the bearing shells into their locations, ensuring that the tab on each shell engages in the notch In the connecting rod and cap. Take care not to touch any shell's bearing surface with your fingers. If the onginal bearing shells are being used for the check, ensure that they are refitted in their original locations. The clearance can be checked in either of two ways. 30 One method is to refit the big-end bearing cap to Ihe connecting rod, ensuring that they are litted the correct way around, with the bearing shells in place. Wilh the cap retaining bolls correctly tightened, use an internal micrometer or vernier caliper to measure the internal diameter of each assembled pair of bearing shells. If the diameter of each corresponding crankshaft journal is measured and Ihen subtracted from the bearing internal diameter, the result will be the big-end beanng running clearance. 31 The second, and more accurate method is to use a product called Plasligauge. Ensure that the bearing shells are correctly fitted then place a strand of Plastlgauge on each (cleaned) crankpin journal. 32 Refit the (clean) piston/connecting rod assemblies to the crankshaft, and refit the bg-end bearing caps, using the marks made or noted on removal to ensure that they are fitted the correct way around. 33 Tighten the beanng cap bolts taking care not to disturb the Plastlgauge or rotate the connecting rod dunng the tightening sequence. 34 Dismantle the assemblies without rotating the connecting rods. Use the scale pnnted on the Plastigauge envelope to obtain the big-end bearing running clearance. 35 If the clearance is significantly different from that expected, the bearing shells may be Ihe wrong size (or excessively worn. If the original shells are being re-used). Make sure mat no dirt or oil was trapped between Ihe bearing shells and the caps or block when the clearance was measured. If the Plastigauge was wider al one end than at the other, the crankshaft journal may be tapered.
2D*10 Engine removal and overhaul procedures
7.40a The arrow on the piston crown must point towards the timing belt end of the engine (petrol engine) 36 On completion, carefully scrape away all traces of the Plastigauge material from the crankshaft and bearing shells. Use your fingernail, or some other object which is unlikely to score the beanng surfaces.
Final piston/connecting rod refitting 37 Ensure that the bearing shells are correctly fitted. If new shells are being fitted, ensure that alt traces of the protective grease are cleaned off using paraffin. Wipe dry the shells and connecting rods with a lint-free cloth. 38 Lubricate the cylinder bores, the pistons, and piston rings, then lay out each piston/con-necting rod assembly in its respective position. 39 Start with assembly No 1. Position the piston ring gaps 120° apart, then clamp them in position with a piston nng compressor. 40 Insert Ihe piston/connecting rod assembly into the top of cylinder making sure it is Ihe correct way round. On petrol engines, ensure that the arrow on the piston crown is pointing towards the timing belt end of the engine and on diesel engines, ensure that the cloverleaf-shaped cut-out on the piston crown is towards the front (oil filter side) of the cylinder block. Using a block of wood or hammer handle against the piston crown, tap the assembly into the cylinder until the piston crown is Hush with the top of the cylinder (sea illustrations). 41 Ensure that the bearing shell is still correctly Installed. Liberally lubricate the crankpin and both bearing shells. Taking care not to mark the cylinder bores, pull the piston/connecting rod assembly down the bore and onto the crankpin.
7.40b Inserting the piston/connecting rod assembly into the cylinder bore using a hammer handle (diesel englno) 42 Refit the big-end beanng cap, tightening Its retaining bolts finger-tight at first, Note that Ihe faces with the identification marks must match (which means that the bearing shell locating tabs abut each other). 43 Tighten the bearing cap retaining bolts evenly and progressively to the specified torque setting. On diesel engines tighten the bolts to the Stage 1 torque then angle-tighten them to the specified Stage 2 angle using an angle-measuring gauge, (see illustrations) 44 Once the bearing cap retaining bolts have been correctly tightened, rotate the crankshaft. Check that il turns freely; some stiffness is to be expected if new components have been fitted, but there should be no signs of binding or tight spots. 45 Refit the remaining three piston/ connecting rod assemblies in the same way. 46 Refit the cylinder head, anti-vibration plate (16-valve engines), oil pump pick-up/filter screen assembly and sump with reference to Chapter 2A, 2B or 2C.
8 Crankshaft -removal and inspection 35
Removal 1 Remove the
sump,
oil pump and pick-up tube, and flywheel/driveplate with reference to the relevant Sections of Chapter 2 Parts A, 8 or C. On 16-valve engines, unbolt and remove the anti-vibration plate from the main bearing caps.
7.43a Torque-tightening the big-end bearing cap bolls (diesel engine) 7.43b Angle-tightening the big-end bearing cap bolts (diesel engine)
Fuel system - diesel models 4C*3
14.6 Nuts securing the exhaust downpipe to the exhaust manifold 14.8 Disconnecting the oil return pipe from tho turbocharger
13 Turbocharger -description and precautions
Description A turbocharger 1$ fitted to TDS, TD and SX models. It increases engine efficiency by raising the pressure In the inlet manifold above atmospheric pressure. Instead of the air simply being sucked Into the cylinders. It Is forced in. Additional fuel is supplied by the injection pump in proportion to the increased air inlet. Energy for the operation of the turbocharger comes from the exhaust gas. The gas flows through a specially-shaped housing (the turbine housing) and In so doing, spins the turbine wheel. The turbine wheel is attached lo a shaft, at the end of which is another vaned wheel known as the compressor wheel, The compressor wheel spins in Its own housing, snd compresses the inlet air on the way to the inlet manifold. Boost pressure (the pressure in the Inlet manifold) is limited by a wastegate, which diverts Ihe exhaust gas away from the turbine wheel In response to a pressure-sensitive actuator. A pressure-operaled switch operates a warning light on the instrument panel in the event of excessive boost pressure developing. The turbo shaft is pressure-lubricated by an oil feed pipe from the main oil gallery The shaft floats on a cushion of oil. A drain pipo returns the oil to the sump.
Precautions The turbocharger operates at extremely high speeds and temperatures. Certain precautions must be observed, to avoid premature failure of the turbo, or injury to the operator. Do not operate the turbo with any of its parts exposed, or with any of ils hoses removed. Foreign objects falling onto the rotating vanes could cause excessive
damage, and (if ejected) personal injury. Do not race the engine immediately after start-up, especially if it Is cold. Give the oil a few seconds lo circulate. Always allow the engine to return to idle speed before switching il off - do not blip the throttle and switch off, as this will leave the turbo spinning without lubrication. Allow the engine to idle lor several minutes before switching off after a high-speed run. Observe the recommended intervals for oil and filter changing, and use a reputable oil of the specified quality. Neglect of oil changing, or use of Inferior oil, can cause carbon formation on the turbo shaft, leading to subsequent failure.
14 Turbocharger -removal and refitting
8 Disconnect the oil return pipe from the turbocharger (see Illustration). 9 Unscrew the bolt securing the mounting bracket to the cyfindar block. 10 Unscrew the mounting nuts and withdraw the turbocharger from the studs in Ihe exhaust manifold. Recover the gasket. II It Is to be refitted, store the turbocharger carefully, and plug its openings to prevent dirt ingress.
Refitting 11 Refitting Is a reversal of removal, bearing in mind the fallowing points: a) if a new turbocharger Is being fitted, change the engine oil and filter. b) Tighten ail nuts and bolts to the specified torque. c) Before starting the engine, prime the turbo lubrication circuit by disconnecting the stop solenoid iead at the injection pump, and cranking the engine on the starter for three ten-second bursts.
Removal 1 Remove the battery as described in Chapter 5A. 2 Unbolt and remove the relay guard and bracket from the left-hand side of Ihe engine. 3 Remove the air cleaner and ducting as descnbed in Section 2. 4 Loosen the clips and remove the air outlet duct between tho turbocharger and inlet manifold. Also disconnect the air inlet duct from the turbocharger. 6 Appty the handbrake, then jack up tho front of the vohicle and support on axle stands (see Jacking and vehicle support). 6 Bend back the locking tabs (if fitted) and unscrew the nuts securing the exhaust downpipe lo the exhaust manifold (see Illustration). Disconnect the downpipe from the exhaust system (refer to Part 4D) end remove it from under the vehicle. Recover tne gasket. 7 Unscrew ihe union nut and disconnect the oil supply pipe from the turbocharger. Recover the copper ring and tape over the end of the pipe 10 prevent dust entry.
15 Turbocharger -examination and renovation l
1 With the turbocharger removed, inspect the housing for cracks or other visible damage. 2 Spin the turbine or the compressor wheel, to verify that the shaft is intact and to feel for excessive shake or roughness. Some play is normal, since in use, the shaft is floating on a film of oil. Check that the wheel vanes are undamaged. 3 The wastegate and actuator are Integral, and cannot be checked or renewed separately. Consul! a Flat dealer or other specialist If it is thought that testing or renewal is necessary. 4 If tho exhaust or induction passages are ail* contaminated, Ihe turbo shaft oil seals have probably failed. 6 No DIY repair of the turbo is possible. A new unit may be available on an exchange basis,