belt FIAT PUNTO 1995 176 / 1.G Service Manual

Diesel engine in-car repair procedures 2C*11

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9.46a The locating dowel in the cylinder block 43 It is possible for the ptston crowns to stnke and damage the valve heads, if the camshaft is rotated v/ith the timing belt removed and the crankshaft set to TDC. For this reason, the crankshaft must be set to a position other than TDC on No t cylinder before the cylinder head is refitted. Use a socket on the crankshaft pulley centre bolt to turn the crankshaft in its normal direction of rotation, until all four pistons are positioned Halfway down their bores, v/ith No 1 piston on lis upstroke - approximately 90° before TDC.
Refitting 44 If the manifolds are being refitted before refitting the cylinder head proceed as follows, otherwise fit the manifolds later when the head is refitted. Ensure thai the inlet and exhaust manifold mating surfaces are completely clean, then locale the new gasket on the studs. 45 Locate the inlet and exhaust manifolds together with the turbocharger, where applicable, on the studs. Refit the nuts and washers and tighten to the specified torque.
sequence
f^/f
9.52b Tighten the cylinder head bolts to the Stage 1 and Stage 2 settings using a torque wrench
on the block 46 Lay the new head gasket on the cylinder block engaging it with the locating dowel. The word ALTO must be uppermost (see illustrations). 47 As a means of locating Ihe cylinder head accurately, cut the heads from two of the old cylinder head bolts. Cut a slot, big enough for a screwdriver blade, in the end of each bolt. These can be used as alignment dowels to assist in cylinder head refitting, however If the head is being refitted without the manifolds it is not necessary to take this action. 48 With the help of an assistant, place the cylinder head assembly centrally on the cylinder block ensuring thai the locating dowels engage with Ihe holes in the cylinder head. Check that the head gasket Is correctly seatod before allowing the full weight of the cylinder head to rest on it. 49 Where necessary, unscrew the home-made alignment dowels, using a flat bladed screwdriver. 50 The oyllnder head bolt threads must be clean. Dip the bolts in engine oil. and allow them to drain for thirty minutes. 51 Carefully enter each bolt with washer into its relevant hole (do not drop them in) and screw in, by hand only, until finger-tight. 52 Working progressively and In the sequence shown, first tighten the cylinder head bolts to their Stage 1 torque setting, using a torque wrench and suitable socket (see illustrations). Go round again, in the sequence shown, and tighten the bolls to the Stage 2 torque setting. 53 Once all the bolts have been tightened to their Stage 2 setting, working again in the
bolts to the Stage 3 and Stage 4 settings
9.46c The word ALTO must be uppermost
given sequence, angle-tighten the bolts through the specified Stage 3 angle, using a socket and extension bar (see illustration). It Is recommended that an angle-measuring gauge is used during this stage of the tightening, to ensure accuracy. If a gauge is not available, use white paint to make alignment marks between the bolt head and cylinder head prior to tightening; the marks can then be used to check tho bolt has been rotated through the correct angle during tightening. Repeat for the Stage 4 setting. 54 Refit the cylinder head front retaining bolts and tighten lo the specified torque. 55 Refit the camshaft cover together with a new gasket and tighten the bolts progressively to the specified torque. 56 The remaining procedure is a reversal of the removal procedure noting the following points. a) Tighten all nut and bolts to the specified torque where given. b) When refitting the metal coolant pipe to the coolant pump, use a new O-ring (see illustration). cj Refit the timing belt with reference to Section 4. d) Use a new exhaust front pipe gasket. e) Refit the auxiliary dhvebeltfs) as described in Chapter 1B. f) Refer to Chapter 4C when refitting the
air
cleaner and air duct. g) Refill the cooling system and fill the engine with new oil with reference to Chapter 1B. 57 Refer to Chapter 20 when starting the engine for the first time.
9.56 Use a new O-ring on the coolant pipe before refitting it to the pump

11.15 Left-hand engine mounting viewed from below 9 lower the engine sufficiently to remove the mounting from the engine bracket. 10 Locate the new mounting in the engine bracket, refit the nut and washers and tighten securely. 11 Raise the engine and refit and tighten the mounting-to-body bolts. 12 Remove the trolley jack and lower the vehicle to the ground. Left-hand mounting 13 If not already done, firmly apply the handbrake, then jack up the front of the car and support It securely on axle stands (see
Jacking
and vehicle support). 14 Place a trolley jack beneath the trans-mission. with a block of wood on the jack head. Raise the jack until it is supporting the weight of the engine/transmission. 15 Unscrew the bolts securing the left-hand mounting to the body (see Illustration). 16 Unscrew the nut securing the mounting to the transmission bracket and recover the washers. 17 Lower the transmission sufficiently to remove the mounting from the transmission bracket. 18 Locate the new mounting in the transmission bracket, refit the nut and washers and tighten securely. 19 Raise the engine and refil and tighten the mounting-to-body bolts. 20 Remove the trolley jack and lower the vehicle to the ground. Rear mounting 21 If not already done, firmly apply the handbrake, then jack up the front of the car and support it securely on axle stands (see
Jacking
and vehicle support). 22 Working beneath the vehicle, unscrew the bolts securing the rear engine mounting to the underbody (see illustration). 23 Temporarily support the weight of the engine/transmission using a trolley jack. 24 Unbolt the rear mounting assembly from the transmission and withdraw from under the vehicle. 25 Unscrew the bolt and separate the bracket from the mounting. 28 Fitting the new mounting is a reversal of tha removal procedure.
Diesel engine in-car repair procedures 2C*11
11.22 Rear engine mounting viewed from below
12 Sump -removal and refitting
Removal 1 Disconnect the battery negativo terminal (refer to Disconnecting the battery in the Reference Section of this manual). 2 Firmly apply the handbrake, then jack up the front of the car and support it securely on axie stands (see Jacking and vehicle support). 3 Drain the engine oil as described in Chap-ter 1B. Where applicable, remove the screws and lower the engine undertray away from the vehicle. 4 On turbo models disconnect the turbo-charger oil drain hose from the sump (see illustration). 5 Working around the outside of the sump, progressively loosen and withdraw the sump retaining bolts. 6 Break the joint by striking the sump with the palm of your hand, then lower the sump and withdraw it from underneath the vehicle. Recover and discard the sump gasket. 7 While the sump Is removed, take the opportunity to check the oil pump pick-up/strainer for signs of clogging. If necessary, clean or renew the strainer.
Refitting 8 Thoroughly clean the sump inside and out ensuring that all traces of gasket are removed from the mating surfaces of both the sump and the cylinder block/crankcase.
12.4 Turbocharger-to-sump oil drain hose
9 Ensure that the mating surfaces are clean and dry, then apply a little grease to the surface of the sump. This will retain the gasket in position while refitting the sump. 10 Lay the new sump gasket In position on the sump mating surface, then offer up the sump and refit the retaining bolts. Tighten the bolts evenly and progressively lo the specified torque. 11 On turbo models reconnect the turbo-charger oil drain hose. 12 Lower the vehicle to the ground then refer to Chapter 1B and refill the engine with the specified grade and quantity of oil. 13 Reconnect the battery negative terminal.
13 Oil pump and pick-up tube -removal, inspection and refitting
Removal 1 The oil pump Is mounted on the timing belt end of the cylinder block and is driven by flats on the crankshaft nose. Incorporated In the oil pump body is the crankshaft oil seal. 2 Remove the timing belt as described in Section 4, and the crankshaft sprocket as described in Section 5. 3 Remove the sump as described in Section 12. 4 Unscrew the bolts securing Ihe pick-up tube to the bottom of the oil pump. Also unscrew the bolt securing the tube to the No 2 main bearing cap. Withdraw the tube from the oil pump and crankcase. Recover the gasket (see illustrations).
13.4a Removing the oil pump pick-up tube... 13.4b ... and gasket

Diesel engine in-car repair procedures 2C*11
X
a 13.14 Fitting the new oil seal to the oil pump casing
S Unscrew the bolts securing the oil pump to Ihe front of the cylinder block and withdraw it over the nose of the crankshaft. Note the location of the bracket (see Illustration). Recover the gasket.
Inspection 8 Prise the oil seal from the front of the oil pump using a screwdriver (see Illustration). 7 Unscrew the crosshead screws and lift off the cover. The screws are tight and are best loosened using an impact driver (see illustration). S Lift out the two rotors keeping them identified for position in relation to each other (see illustrations). 9 Depress the relief valve collar, then extract the retaining plate and withdraw the seat, spring and valve (see illustrations). 10 Clean the pump thoroughly, and Inspect the rotors for signs of damage or wear. Using a feeler blade, check the wear between the outer rotor and oil pump casing. Using the feeler blade and a straight-edge, check the endptay of Ihe rotors. If the rotors are worn in excess of the specified amount given in Specifications, the oil pump should be renewed as a complete unit (see Illustrations). 11 Check the condition of the relief valve and seating - If worn excessively the pump must be renewed. 12 If the components are In good condition, reassemble the pump using a reversal of the dismantling procedure. Before fitting the cover the rotors should be oiled and the cavity
13.15 Engine oil dipstick rubber grommet in the oil pump casing between them filled with clean engine oil. Make sure the cover screws are fully tightened. 13 Thoroughly clean the mating surfaces of the oil pump and cylinder block. 14 Dip the new oil seal in engine oil then locate it on the front of the oil pump with the sealing lips facing Inwards. Use a suitable tubular drift (or socket) to drive the seal into the oil pump casing (see illustration). 16 Examine the dipstick tube rubber grommet in the oil pump and renew il If necessary (see illustration).
Refitting 16 Smear a little engine oil on both sides of the new gasket then locate it on the cylinder block (see illustration), 17 To prevent damage to the new oil seal as it is passed over the nose of the crankshaft, wrap some adhesive tape around it and lightly oil it. 18 Carefully locate the oil pump over the crankshaft taking care not to damage the oil seal then Insert the bolts loosely. Remove the adhesive tape (see Illustration). 19 Using a straight-edge, position the oil pump so that the sump mating surface Is level with the surface of the crankcase (see illustration). With the pump correctly positioned, securely tighten the bolts in an even and progressive sequence. 20 Refit the oil pick-up tube together with a new gasket, and securely tighten the mounting bolts. 21 Refit the sump with reference to Section 12.
13.16 Positioning the oil pump gasket on the cylinder block 22 Refit the crankshaft sprocket with reference to Section 5 and the timing belt with reference to Section 4. 23 When starling the engine, let it Idle until the oil pressure warning light goes out.
14 Oil cooler -removal and refitting I I
Removal 1 The oil cooler is located on the right-hand side of the engine compartment. First remove the front bumper as described In Chapter 11. 2 Unbolt the support bar for the radiator and oil cooler. 3 Support the oil cooler then unscrew the upper mounting boll. Lower the cooler to the extent of the hoses. 4 Position a container beneath the cooler then unscrew the Inlet and outlet union nuts and disconnect the hoses from the oil filter. Note the fitted positions of the hoses for correct refitting. Allow the oil to drain into the container. 5 Fully unscrew the union nuts and disconnect the hoses from the oil cooler.
Refitting 6 Refitting is a reversal of removal, but top-up the engine oil level as necessary. Run the engine and check for leaks.
13.18 Locating the oil pump over the end of the crankshaft 13.19 Checking that the oil pump and sump mating surfaces are correctly aligned with a straight-edge

2D*10 Engine removal and overhaul procedures
Engine and transmission -removal, separation, connection and refitting
Note: The engine Is lowered from the engine compartment as a complete unit with the transmission; tho two are then separated for overhaul.
Removal 1 Remove the bonnet and disconnect the washer tubing as described in Chapter 11 (see illustrations). 2 Apply the handbrake, then jack up the front of the vehicle and support on axle stands (see Jacking and vehicle support). Remove both front wheels. In order to remove tne engine/transmission assembly in an upright position from under the vehicle, there must be a minimum clearance of 660 mm between the floor and the front crossmember. Additional height Is necessary if the assembly is to be lowered onto a trolley. 3 Where fitted, unbolt and remove the engine compartment lower cover. 4 Remove the auxiliary drivebelt(s) with reference to Chapter 1A or 1B. 5 Dram the engine oil. transmission oil/fluid and coolant with reference to Chapter 1A or 1B. 6 Remove the battery (see Chapter 5A). 7 On manual transmission models with a cable dutch, disconnect the clutch cable from the transmission (refer to Chapter 6). On manual transmission models with a hydraulic clutch unbolt the clutch slave cylinder from the top of the transmission then fit a cable-tie around it to prevent the piston coming out (see Illustration). Position the cylinder to one side. 8 Unscrew the nut and disconnect the earth lead from the transmission (see illustration). Petrol engines 9 Unbolt and remove the battery tray. 10 Disconnect the wiring from the reversing light switch. 11 On manual transmission models disconnect the reverse Inhibition cable from the transmission then disconnect the gear selector rod from the lever on the transmission. 12 Remove the air cleaner and ducting as descnbed In Chapter 4A or 4B. 13 On automatic transmission models disconnect the kickdown cable and gear selector cable as described in Chapter 7B. Also disconnect the wiring for the electro-magnetic clutch. 14 Unbolt and remove the cover from the bulkhead then disconnect the oxygen sensor wiring. 15 Disconnect the remaining wiring at the bulkhead and release the fuse holders at the mounting. 16 Disconnect the vacuum pipe from the inlet manifold, and also disconnect the wiring connector located next to it.
4.1a Unscrewing the bonnet hinge bolts
17 Unscrewthenutsandseparatetheengine wiring harness lead from the battery positive cable terminal. 18 Disconnect the accelerator cable from the engine as described in Chapter 4A or 4B, 19 Loosen the clip and disconnect the radiator top hose from the elbow on the left-hand end of the cylinder head. Similarly disconnect the bottom hose. On 16-valve models, remove the radiator electric cooling fan as described in Chapter 3. 20 Identify the hoses connected to the throttle housing, then disconnect them. 21 Identify the coolant heater hoses on the bulkhead for position, then loosen the clips and disconnect the hoses. 22 Loosen the clip and disconnect the brake servo vacuum hose from the Inlet manifold. Where applicable, disconnect the remaining emission control system vacuum hoses from the Inlet manifold after Identifying their locations to aid refitting. 23 Disconnect tho fuel supply and return hoses from the throttle housing. 24 Release the connector from the ignition/fuel ECU located on the right-hand side of the engine compartment. 25 Unscrew the nut and detach the earth cable from its location near the ECU. 26 Disconnect the diagnostic connector located near the ECU. 27 On models fitted with power steering, refer to Chapter 10 and unbolt the power steering pump from the front of the engine without disconnecting the hydraulic fluid lines then tie It to one side so that it will not obstruct the removal of the engine. On
4.1b Disconnecting the washer tubing
models with air conditioning, similarly unbolt the air conditioning compressor and position it clear of the engine. Do not disconnect the air conditioning refngerant pipes/hoses. 26 On manual transmission models pull out the retaining plate and disconnect the gear selector cable from the lever on the transmission. 29 Unscrew the nuts retaining the track rod ends on the swivel hubs and use a balljoint separator tool to disconnect them. 30 Release the flexible brake fluid hoses and ABS system sensor wrring from the front suspension struts. 31 On manual transmission models, unscrew the nuts from the outer ends of each driveshaft. To prevent the hubs from turning either have an assistant depress the brake pedal, or temporarily Insert two wheel bolts and use a lever to hold the hub. 32 On automatic transmission models use a suitable drift to drive out Ihe roll pins securing 2D the inner ends of the drlveshafts to tho trans-mission output stubs. Turn the driveshalts as necossary to access the roll pins . 33 Unscrew the two bolts securing the right-hand swivel hub assembly to the front suspension strut, then move the hub assembly outwards. On manual transmission models release the outer end of the driveshaft from the hub assembly - on automatic transmission models slide the inner end of the driveshaft off the final drive output stub. Take care not to strain the flexible brake hose while doing this. Move the driveshaft to one side thon temporanly refit the hub assembly to the strut. On manual transmission models, make
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4.7 Fit a cable tie around the dutch slave cylinder to prevent the piston coming out 4.8 Disconnecting the earth lead from the transmission

2D*10 Engine removal and overhaul procedures
4.44a Disconnecting tho radiator top hose from the thermostat housing
4.45b ... and expansion tank hose
lofi-nand side of the cylinder head, From the top ot the radiator and from the expansion tank (see Illustrations). 46 Disconnect the radiator bottom hose from the elbow on the cylinder head.
4.49e ... and the adjustment lockbolt...
4.44b Disconnecting the heater hose st the engine
4.49a Remove the front bracket bolt...
47 On models with a speedometer cable, disconnect the cable from the transmission. 48 On models with an electronic speedometer, if necessary disconnect the winng connector on the support bracket. The cable may be left
4.49f ... and tie the power steering pump to the bulkhead
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4.45a Disconnecting the heater return hose...
4.49b ... the belt adjustment bolt...
attached if Ihe transmission Is not being detached from the engine. 49 On models fitted with power steering, unbolt the power steering pump from the rear right-hand side of the engine without disconnecting the hydraulic fluid lines then tie it to one side on the bulkhead so that it will not obstruct the removal of the engine. To do (his first remove the front bracket bolt, remove the belt adjustment bolt, remove the rear through-bolt, lift away the cover and remove the adjustment lockbolt (see illustrations). On models with air conditioning, similarly unbolt the air conditioning compressor and position It clear of the engine. Do not disconnect the air conditioning refrigerant pipes/hoses. 50 Disconnect the coolant purge hoses from the top of the radiator and expansion tank (seo illustrations). 51 Disconnect the accelerator cable from the injection pump (see Chapter 4Q.
4.50a Disconnecting the coolant purge hoses from the radiator...

2D*10 Engine removal and overhaul procedures
05 Remove the brush holder assembly from the automatic transmission as described in Chapter 7B, Section 4. The brushes bear on the slip rings at the rear of the electro-magnetic clutch housing and they may be damaged when the transmission is removed. 86 Unscrew and remove the transmission-to-engine bolts then carefully draw the transmission away from the engine, resting It securely on wooden blocks. Collect the locating dowels If they are loose enough to be extracted, 87 If the oil pump driveshaft remains engaged with the crankshaft, remove it and reert Into the transmission to protect It from damage.
Connection 86 If the engine and transmission have not been separated, go to paragraph 104. Manual transmission models 89 Smear a little high-melting-point grease
on
the splines of the transmission input shaft. Do not use an excessive amount as there Is the risk of contaminating the clutch friction plate. 90 Carefully offer up the transmission to the engine cylinder block, guiding the input shaft through the clutch friction plate. 91 Refit the transmission-to-engine bolts and
the
single nut. hand^jghtenlng 1hem to secure the transmission in position. Note: Do not hghten them to force the engine and transmission together. Ensure that the beilhousing and cylinder block mating faces will butt together evenly without obstruction, before finally tightening the bolts and nut securely. Automatic transmission models 92 Check that the oil pump driveshaft is correctly engaged with the oil pump in the transmission. 93 Carefully offer up the transmission to Ihe rear of the engine and insert the oil pump driveshaft In the centre of the electro-magnetic clutch housing. Locate the transmission on the locating dowels then Insert the bolts and tighten them securely. 94 Refit the brush holder assembly to the automatic transmission with reference to Chapter 7B, Section 4. Petrol engines 96 Refit the transmission lower cover and tighten the bolts. 96 Locate the support bracket on the lower cover, then insert the bolts hand-tight. Also Insert the bolts securing the bracket lo the rear of Ihe cylinder block. With all the bolts Inserted, tighten them securely. 97 Refit the earth leads and tighten the bolts. Diesel engines 98 Refit the rpm sensor and tighten the bolts. 99 Insert the Intermediate shaft through the bracket then locate the dust boot on it and insert the Inner end in the transmission.
100 Refit and tighten the bolts securing the Intermediate shaft to the bracket on the rear of the cylinder block. 101 Refit the transmission lower cover and tighten the bolts. Ail models 102 Refit the starter motor (see Chapter 5A). 103 Refit the wiring harness to the components on the engine/transmission assembly making sure it is routed correctly.
Refitting 104 Locate the engine/transmission assembly beneath the engine compartment and attach the hoist to the lifting eyes. 105 Carefully lift the assembly up into the engine compartment taking care not to damage the surrounding components. 106 Reconnect the left-hand engine/trans-mission mounting to the body and tighten the bolts. 107 Reconnect Ihe right-hand engine mounting to the body and tighten the bolts. 108 Working beneath the vehicle, refit the rear engine mounting and tighten the bolts. 109 Disconnect the hoist from the engine and transmission lifting eyes and remove the hoist from under the vehicle. 110 The remainder of the refitting procedure is the direct reverse of the removal procedure, noting the following points:
a) Ensure that alf sections of the wiring harness follow their original routing; use new cable-ties to secure the harness In position, keeping it away from sources
of
heat and abrasion. b) On vehicles with manual transmission check and if necessary adjust the gearchenge cable and rod with reference to Chapter 7A. c) On vehicles with automatic transmission use new ro//p/ns fo secure the driveshafts to the transmission output stubs. Also check and if necessary adjust the kickdown end selector cables with reference to Chapter 78. d) Ensure that afi hoses are correctly routed and are secured with the correct hose clips, where applicable. If the hose clips cannot be used again; proprietary worm drive clips should be fitted
In
their place. e) Refill the cooling system as described in Chapter 1A or 18. f) Refill the engine with appropriate grades and quantities of oil (Chapter
1A
or 1B). g) Refit and adjust the auxiliary drivebelt(s) wfth reference fo Chapter 1A or 1B. h) Check and If necessary adjust the accelerator cable with reference to Chapter
AA,
48 or
AC.
i) When the engine is started for the first time, check for
air,
coolant, lubricant and fuel leaks from manifolds, hoses etc. If
the
engine has been overhauled, read
the
notes In Section 13 before attempting to starlit.
5 Engine overhaul • dismantling sequence
1 It is much easier to dismantle and work on the engine if it is mounted on a portable engine stand. These stands can often be hired from a tool hire shop. Before the engine is mounted on a stand, the flywheel should be removed, so that the stand bolts can be tightened Into the end of the cylinder block/crankcase. 2 If a stand Is not available, it Is possible to dismantle the engine with it blocked up on a sturdy workbench, or on the floor, Be very careful not to tip or drop the engine when working without a stand. 3 If you intend to obtain a reconditioned engine, all anclllarles must be removed first, to be transferred to the replacement engine (just as they will If you are doing a complete engine overhaul yourself). These components Include the following:
Petroi engines a) Power steering pump if removed with the engine (Chapter
10).
b) Alternator fmcluding mounting brackets) and starter motor (Chapter
SA).
c) The Ignition system and HT components including ail sensors, HT leads and
spark
plugs (Chapters 1A and
SB).
d) The fuel injection system components (Chapters A A and
AB).
e) All electrical switches, actuators and sensors, and the engine wiring harness (Chapters 4A, AB, SB). f) Inlet and exhaust manifolds (Chapters 4A, AB end
AD).
g) Engine oil dipstick and tube. h) Engine mountings (Chapter
2A).
i) Flywheef/driveptate (Chapter
2A).
j) Clutch components (Chapter
6)
- manual transmission. k) Electro-magnetic clutch components (Chapter 7B) - automatic transmission. I) Cooling system components (Chapter
3).

Diesei engines a) Power steering pump //removed with the engine (Chapter
10).
b) Alternator (Including mounting brackets) and starter motor (Chapter 5A). c) The glow plugfpre-heatlng system components (Chapter
SC).
d) Ait fuel system components, including the fuel injection pump, all sensors and actuators (Chapter
AC).
e) The vacuum pump. f) Ail electrical switches, actuators and sensors, and the engine wiring harness (Chapter 4C and 5C). g) Inlet and exhaust manifolds and, where applicable, the turbocharger (Chapter
AC
and 4D). h) The engine oil level dipstick and its tube. i) Engine mountings (Chapter
2C).

2D*10 Engine removal and overhaul procedures
6.5s Prising out the feed stub of the camshaft lubricating pipe J) Flywheel (Chapter 2C). k) Clutch components (Chapter
6).
I) Cooling system components (Chapter
3).
Note: When removing trie external components from the engine, pay close attention to details that may be helpful or important during refitting. Note the fitted position of gaskets, seals, spacers, pins, washers, bolts, and other small components. 4 If you are obtaining a short engine (the engine cylinder block/crankcase, crankshaft, pistons and connecting rods, all fully assembled), then the cylinder head, sump, oil pump, timing belt (together with its tensloner and covers), coolant pump, thermostat housing, coolant outlet elbows, oil filter housing and where applicable oil cooler will also have to be removed. 5 If you are planning a full overhaul, the engine can be dismantled in the order given below: $) Ftywhaoi/drivoplate.
6.5d When removing the camshaft bearing caps, note the position of the (ong and short locating dowels
bearing/banjo union bolt b) Timing belt, sprockets, and tensioner. c) Inlet and exhaust manifolds. d) Cylinder head. e) Sump. f) Oil pump. g) Pistons and crankshaft.
6 Cylinder head - % dismantling, cleaning, inspection and reassembly ^
Note: Now and reconditioned cylinder heads are available from the manufacturer or engine overhaul specialists. Be aware that some specialist tools are required for the dismantling and inspection procedures, and new com-ponents may not be readily available. It may therefore be mors practical and economical for the home mechanic to purchase a reconditioned head, rather than dismantle, inspect and recondition the original head.
Dismantling Note: On 8-valve petrol engines and diesel engines, the camshaft and cam followers are /oca fed In the cylinder head assembly and the relevant dismantling and reassembly procedures are contained in this Section. On 1$-valve petrol engines, the camshafts and cam followers are /oca fed In a separate housing (cylinder head extension) which is bo/fed fo the top of the cylinder head. All procedures relating to the camshafts and cam followers on 16-valve engines are therefore contained in Chapter 2B. Proceed fo paragraph 15 for cylinder head dismantling
6.8a Unscrew and remove the bolts from the thermostat housing, noting the location of the bracket
6.5c Removing the camshaft lubricating pipe procedures on /6-vafve engines, and ignore any references to camshafts, cam followers and oil seals in the paragraphs that follow. 1 Remove the cylinder head as described in Part A. B or C of this Chapter (as applicable). 2 If not already done, remove the inlet and exhaust manifolds with reference to the relevant Part of Chapter 4. Also remove the spark plugs, glow plugs and injectors as applicable. 3 Remove the camshaft sprocket with reference to Chapter 2A or 2C. Petrol engines 4 Mark the positions of the camshaft bearing caps, numbering them from the timing end. 5 Unbolt and remove the lubrication pipe (prise the oil feed stub out with a screwdriver). Unscrew the remaining bolts and take off the bearing caps (see illustrations). 6 Lift the camshaft carefully from the cylinder head, checking lhat the valve clearance shims and cam followers are not withdrawn by the adhesion of the oil (see Illustration). 7 Remove the shims and cam followers, but keep them In their originally fitted order. Diesel engines 8 Unbolt the thermostat housing and gasket, and vacuum pump from the left-hand end of the cylinder head. Also if necessary unbolt the coolant cover and gasket from the right-hand end of the head. Note the location of brackets (see illustrations) 9 Using a soft metal drift, carefully lap out the left-hand side mount and recover the gasket (soe illustrations). 10 At tho timing bait end of the cylinder head.
6.8b Removing the thermostat housing ... 6.6 Removing the camshaft

2D*10 Engine removal and overhaul procedures

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6.8c ... and gasket
unscrew the bolts securing the right-hand Side mount to the head. Carefully tap out the right-hand side mount and recover the gasket (see illustrations). 11 Mark the positions of the camshaft bearing
6.10a Removing tho camshaft right-hand side mount...
6.12b ... and remove the bearing caps
6.8d Unscrew the vacuum pump mounting nuts noting the location of the bracket
caps, numbering from the timing belt end. 12 Progressively unscrew the bearing cap nuts then take off the bearing caps. Note the location dowels on the mounting studs (sae Illustrations).
6.12c The camshaft mounting studs incorporate location dowels
6.8e Removing the vacuum pump
13 Lift the camshaft towards the timing end. then remove it from the cylinder head (see illustration). Make sure the valve clearance shims and cam followers are not withdrawn by the adhesion of the oil.
6.13 Removing the camshaft from the cylinder head
expert22 fl/in http://rutracker.org

2D*10 Engine removal and overhaul procedures
6,14a Removing the shims... 6.14b ... and cam followers 6.16a Removing the upper spring seat...
14 Remove Ihe shims and cam followers, but keep them In their onginally fitted order (see illustrations) All engines 15 Stand the cylinder head on its end. Using a valve spring compressor, compress each valve spring in turn, extracting the split collets when the upper valve spring seat has been pushed far enough down the valve stem to free them. If the spring seat sticks, lightly lap Ihe upper |aw of the spring compressor with a hammer to free It. 16 Release tho valve spnng compressor and remove the upper spring seat, valve spring and lower spring seat (see illustrations) 17 Withdraw the valve from the head gasket side of the cylinder head, then use a pair of pliers to extract the valve stem oil seal from the top of the guide (see illustrations). If the
valve slicks In the guide, carefully deburr the end face wilh fine abrasive paper. Repeat this process for the remaining valves. 18 On diesel engines, if Ihe swiri chambers are badly coked or burned and are in need of renewal, they may be removed by unscrewing the retaining collars and carefully tapping them out from the combustion chamber side. Recover the washers and keep them identified for position (see illustration). 19 It is essential that each valve is stored together with Its collets, retainer, spring, and spring seat. The valves should also be kept in (heir correct sequence, unless they are so badly worn that they are to be renewed. If they are going to be kepi and used again, place each valve assembly in a labelled polythene bag or similar small container (see Illustration). Note that No 1 valve is at the timing belt end of Ihe engine.
Cleaning 20 Using a suitable degreasing agent, remove all traces of oil deposits from the cylinder head, paying particular attention to tho journal bearings, cam follower bores, valve guides and oilways. as applicable. Scrape off any traces ot old gasket from the mating surfaces, taking care not to score or gouge them. If using emery paper, do not use a grade of (ess than 100. Turn the head over and using a blunt blade, scrape any carbon deposits from the combustion chambers and ports. Caution: Do not erode the seeling surface of tho valve seat. 21 Finally, wash the entire head casting with a suitable solvent to remove the remaining debns. 22 Clean the valve heads and stems using 8 fine wire brush. If the valve is heavily coked,
5.18 Swirl chamber retaining collar (diesel engine) 6.19 Keep groups of components together in labelled bags or boxes

2D*10 Engine removal and overhaul procedures
7.13 Positioning of piston rings (petrol engine) 11 Scrape away all traces of carbon from the top of the piston. A hand-held wire brush (or a piece of fine emery cloth) can be used, once the majority ot the deposits have been scraped away. 12 Remove the carbon from the ring grooves In the piston, using an old ring. Break the ring in half to do this (be careful not to cut your fingers - piston rings are sharp). Be careful to remove only the carbon deposits • do not remove any metal, end do not nick or scratch the sides of the ring grooves. 13 Once the deposits have been removed, clean the piston/connecting rod assembly with paraffin or o suitable solvent, and dry thoroughly. Make sure that the oil return holes In the ring grooves are clear. Fit the rings to their respective grooves meking sure they are positioned the correct way round where applicable (see illustration). 14 If the pistons and cylinder bores are not
7.22 Prising out the gudgeon pin retaining circilps damagea or worn excessively, and if the cylinder block does not need to be rebored. the original pistons can be refitted. Normal piston wear shows up as even vertical wear on the piston thrust surfaces, and slight looseness of the top ring In its groove. New piston rings should always be used when the engine is reassembled. 15 Carefully inspect each piston for cracks around the skirt, around the gudgeon pin holes, and at the piston nng lands (between the ring grooves). 16 Look for scoring and scuffing on the ptston skirt, holes in the piston crown, and burned areas at the edge of the crown. If the skirt is scored or scuffed, the engine may have been suffering from overheating, end/or abnormal combustion which caused excessively high operating temperatures. The cooling and lubrication systems should be checked thoroughly. Scorch marks on the sides of the pistons show that blow-by has occurred. A hole in the piston crown, or burned areas at the edge of the piston crown, Indicates that abnormal combustion has been occurring. If any of the above problems exist, the causes must be investigated and corrected, or the
7.26a Piston to connecting rod assembly (petrol engine) 1 Piston grade (A) end directional arrow on piston crown (towards timing belt end) 2 Connecting rod/cap matching numbers 3 Gudgeon pin offset in piston (0.9 to 1.1 mm) Arrow indicates direction of crankshaft rotation
7.26b Piston to connecting rod assembly (diesel engine) 1 Piston crown
damage will occur again. The causes may Include Incorrect Ignition/injection pump timing, or a faulty injector (as applicable). 17 Corrosion of the piston, in the form ol pitting, indicates that coolant has been leaking into the combustion chamber and/or the crankcase. Again, the cause must be corrected, or the problem may persist In the rebuilt engine. 16 Examine each connecting rod carefully for signs of damage, such as cracks around the big-end and small-end bearings. Check that the rod is not bent or distorted, Damage is highly unlikely, unless the engine has been seized or badly overheated. Detailed checking of the connecting rod assembly can only be earned out by an engine repair specialist with the necessary equipment. 19 Although not essential. It is highly recommended that the big-end cap bolts are renewed as a complete set prior lo refitting. 20 On petrol engines piston and/or con-necting rod renewal should be entrusted to an engine repair specialist, who will have the necessary tooling to remove and install the interference fit gudgeon pins. 21 On diesel engines, the gudgeon pins are of the floating type, secured in position by two circlips. On these engines, the pistons and connecting rods can be separated as follows. 22 Using a small fiat-bladed screwdriver, prise out ihe circlips, and push out the gudgeon pin (see illustration). Identify the piston and rod to ensure correct reassembly. Discard the circlips - new ones must be used on refitting. 23 Examine the gudgeon pin and connecting rod small-end bearing bush for signs of wear or damage. Bush renewal should be entrusted to an engine overhaul specialist. 24 The connecting rods themselves should not be In need of renewal, unless seizure or some other major mechanical failure has occurred. Check the alignment of the connecting rods visually, and if the rods are not straight, take ihem to an engine overhaul specialist for a more detailed check. 25 Examine all components, and obtain any new parts as necessary. If new pistons are purchased, they will be supplied complete with gudgeon pins and circlips. 26 On reassembly position the piston on the connecting rod as shown (see Illustrations),
Injection pump location Connecting rod/cap matching numbers 7.28c Piston crown on diesel engines