1998 FIAT PUNTO Manual transmission

ia.14 Every 20 000 miles - petrol models
16 Test the operation of the brake servo unit as follows. With the engine off, depress the footbrake four or five times to exhaust the vacuum. Hold the brake pedal depressed, then start the engine. As the engine starts.
there should be a noticeable give In the brake pedal as vacuum builds up. Allow the engine to run for at least tsvo minutes, and then switch it off. If the brake pedal is depressed now. it should be possible to detect a hiss
from the servo as the pedal is depressed. After about four or five applications, no further hissing should be heard, and the pedal shouto feel considerably harder.
Every 30 000 miles (45 000 km) or 3 years
. transmission (see illustration). Using an Allen 25 Lambda/oxygen sensor ^ key, unscrew the plug and clean it. check \ 3 The oil level should reach the lower edge of ^ the filler/level hole. A certain amount of oil will have gathered behind the filler/level plug, and If the CO level at the exhaust tailpipe is too w,u tr,cWe out when is 'e™oved; this does high or low, Ihe vehicle should be taken to a «©l necessarily Indicate that the level is Fiat dealer so lhat the complete fuel-injection correct. To ensure that a true level is and ignition systems, including the Lamoda/ established, wait until the Initial trickle has oxygen sensor, can be thoroughly checked stopped, then ado oil as necessary until a using the special diagnostic equipment. Once ,r,ckle o1 new oil can be seen emerging. The these have been checked and are known to 'W wl" be correct when ,he flow ceases-us® be free from faults, the fault must be in the good-quality oil of the specified type, catalytic converter, which must be renewed Make sur®that vehicle Is completely level as described In Chapter 4D, Section 6. checking the level and do not overfill, 4 When the level Is correct refit and tighten the plug and wipe away any spilt oil.
26 Manual transmission oil level check ^ 27 Evaporative loss system ^ check
1 Park Ihe vehicle on a level surface, If possible over an inspection pit or on a ramp as the filler/level plug is best reached from under Ihe engine compartment. The oil level must be checked before the car is driven, or at least 5 minutes after the engine has been switched off. If the oil ts checked Immediately alter driving the car, some of the oil will remain distributed around the transmission components, resulting in an inaccurate level reading. 2 Wipe clean the area around the filler/level plug, which is situated on the front of the
Refer to Chapter 40 Section 2 and check that all wiring and hoses are correctly connected to the evaporative toss system components.
28 Automatic transmission fitter and fluid change
1 Take the vehicle on a short run. to warm the transmission up to operating temperature.
Park the car on level ground, then switch off the Ignition. 2 Firmly apply the handbrake, then jack up the front of the car and support It securely on axle stands (see Jacking and vehicle support]. Note thai, when refilling and checking Uie fluid level, the car must be lowered to the ground, and level, to ensure accuracy. 3 Remove the dipstick, then position a suitable container under the transmission, Unscrew the sump drain plug and allow the fluid to drain for at ieast 10 minutes. Refit and tighten the drain plug when the fluid has completely drained.

A


Warning: The transmission fluid may be very hot and precautions must be taken to avoid scalding.
4 Clean around the transmission sump mating flange. Unboll and remove the sump and remove the gasket. 5 Remove the two bolts and withdraw the transmission fluid filter {see illustration). 6 Fit the new filter, and secure It with the two bolts. 7 Refit the sump using a new gasket, then
_
lower the vehicle to the ground, 8 Fill the transmission with the specified quantity of fluid via Ihe dipstick tube, using a funnel with a fine mesh filter. 9 Run the engine to normal operating temperature, then check the fluid level as described In Weekly checks. 10 Dispose of the old fluid safely.
26.2 Transmission filler/level plug location 28.5 Automatic transmission fluid filter retaining bolts

Maintenance procedures - petrol models 1A.15
Every 40 000 miles (60 000 km) or 4 years
29 Rear brake shoe check
1 Chock the front wheels then Jack up the rear of Ihe car and support it on axle stands (see Jacking and Vehicle Support). Remove the rear roadwheels. 2 Using the inspection hole at the edge of the brake drum, check that the linings are not worn below Ihe minimum thickness given in the Specifications (see illustration). If necessary use a torch. 3 If the friction material on any shoe is worn down to the specified minimum thickness or
less,
all four shoes must be renewed as a set. 4 At the same time check for signs of brake
Kutti
leakage. 5 For a comprehensive check, the brake drum should be removed and cleaned. This
will allow the wheel cylinders to be checked, and the condition of the brake drum itself to be fully examined (see Chapter 9). 6 Refit the lubber plugs then lower the car to the ground.
30 Timing belt renewal
Refer to Chapter 2A or 2B. Note: Although the norma/ interval for timing belt renewal is 70 000 miles (105 000 km), it is strongly recommended that the interval Is reduced on vehicles which are subjected to intensive use. ie, mainly short journeys or a lot of stop-start driving. The actual belt renewal interval is therefore very much up to the individuaf owner. That being said, it is highly recommended to err on the side of safety, and
29.2 Check the thickness of the shoe friction material through the hole on the edge of the drum (arrowed)
renew the belt at 40 000 miles (60 000 km), bearing in mind the drastic consequences resulting from belt failure.
Every 60 000 miles (90 000 km) or 6 years
31 Emission control system check
Refer to Chapter 4D. A full check of the emissions control systems must be made by a Fiat dealer.
Every 80 000 miles (120 000 km)
32 Manual transmission all renewal S
1 Park the vehicle on a level surface, if possible over an inspection pit or on a ramp as the filler/level and drain plugs are accessed from order
the
engine compartment. If necessary
Jack
ip the vehicle and support on axle stands (see
Jacking and vehicle
support). 2 Wipe clean the area around the filler/leval And drain plugs, which are on the front and bottom of the transmission (see illustration).
3 Using an Allen key. unscrew the filler/level plug and clean it. 4 Position a suitable container beneath the transmission, then use the Allen key to unscrew the drain plug. Allow the oil to completely drain. 5 Wipe clean the drain plug then refit and tighten It. 6 Fill the transmission with ihe correct grade and quantity of oil, referring to Section 26 when checking the level. Refit and lighten the filler/level plug. 7 Where applicable lower the vehicle to the ground. 32.2 Transmission drain plug location (viewed from under the vehicle)
Every 2 years (regardless of mileage)
33 Coolant renewal
I
Cooling system draining

A


Warning: Walt until the engine Is cold before starting this pro-cedure. Do not allow antifreeze to come In contact with your skin, or with the painted surfaces of the vehicle. Rinse off spills immediately with plenty of water.
Ndver
leave antifreeze lying around In an open container, or fn a puddle In the
driveway or on the garage floor. Children and pets are attracted by its sweet smell, but ant/freeze can be fatal if ingested. 1 With the engine completely cold, cover the expansion tank cap with a wad of rag. and slowly turn the cap anticlockwise to relieve the pressure in the cooling system (a hissing sound will normally be heard). Wait until any pressure remaining in the system is released, then continue to tum the cap until it can be removed. 2 Position a suitable container beneath the radiator bottom hose connection, then release the retaining clip and ease the hose from the radiator stub (see illustration). If the hose 33.2 Disconnecting the radiator bottom hose to drain tho coolant

1B»1
Chapter
1
Part B:
Routine maintenance & servicing - diesel models
Contents
Air filter renewal 13 Auxiliary drivebelt(s) check and renewal 16 Brake fluid renewal 2d Brake warning lamp operation check 5 Clutch adjustment check 17 Coolant renewal 27 Drtv«shaft gaiter check 10 Emissions control systems check 25
Engage
oil and filter renewal 3 Exhaust system check 9 Front brake pad check 6
Fuel
fitter renewal 12 Fuel Filter water draining 4 Headlight beam adjustment 20
Hinge and lock lubrication 19 Hose and fluid leak check 6 Idle speed check and adjustmenl 11 Introduction ... 1 Manual transmission oil level check 22 Manual transmission oil renewal - 26 Pollen filter renewal 14 Rear brake shoe check 23 Regular maintenance 2 Road test 21 Steering and suspension check 15 Timing belt renewal 24 Underbody sealant check 7 Valve clearance check and adjustment 16
^m
Degrees of difficulty
Easy, sutable for % Fairly easy, suitable FaHycifficult, i'. Difficult, suitable fa Very difficult, novice with irttte % for beginner with suitable for competent experienced DIY
1
suitable for expert DIY * or professional jQ experience some experience DIY mechanic mechanic 1
suitable for expert DIY * or professional jQ

1B.2
Servicing specifications - diesel models
Lubricants and fluids Refer to end of Weekly checks on page 0*17
Capacities Engine oil (including filter) Non-turbo diesei engine 4.95 litres Turbo diesel engine 4.84 litres Cooling system 7.2 litres
Manual transmission Non-turbo diesel engine 2.37 litres Turbo diesei engine t .98 litres Power-assisted steering 0.65 litres
Fuel tank 47 litres Washer reservoir Without headlight washers 2.5 litres With headlight washers 7.0 litres
Engine Oil fitter Engine Idle speed: Non-turbo diesel engine Turbo diesel engine Auxiliary drivebelt tension ...... Valve clearances • engine cold: Inlet Exhaust
Champion C112
8l0«40rpm 900 ± 20 rpm 5.0 mm deflection midway between pulleys
0.30 mm * 0.05 mm 0.35 mm ± 0.05 mm
Cooling system Antifreeze mixture: 50% antifreeze Protection down to-35°C Note: Refer to antifreeze manufactuivr for latest recommendations.
Fuel system Air filter element: Non-turbo diesel engine (with Lucas/CAV Injection) Champion U611 Turbo diesel engine (with Bosch Injection) Champion U579 Fuel filter Champion L120
Brakes Brake pad lining minimum thickness 1-5 mm Brake shoe friction material minimum thickness 2.0 mm
Tyre pressures See end of Weekly checks on page 0*18
Torque wrench settings Fuel filter bracket to body ..... « Fuel filter to bracket i........ Manual transmission oil drain plug: Non-turbo diesel engine: Stage 1 Stage 2 Turbo diesel engine Manual transmission oil filler plug Roadwheel bolts
Nm Ibfft 18 13 24 18
12 9 Angle-tighten a further 180® 46 34 46 34

Maintenance schedule - diesel models 1B.3
The mamtenance intervals in this manual are provided with the assumption that you. reI ihe dealer, will be carrying out the work.
These
are the minimum maintenance intervals recommended by us for vehicles driven daily.
ff you wish to keep your vehicle In peak condition at all times, you may wish to perform some of these procedures more often. We encourage frequent maintenance, because it enhances the efficiency.
performance and resale value of your vehicle. When the vehicle Is new, it should be serviced by a factory-authorised dealer service department, in order to preserve the factory warranty.
Every 250 miles (400 km) or weekly O Refer to Weekly checks
Every 5000 miles (7500 km) or

6
months - whichever comes first • Renew the engine oil and filter (Section 3) P Drain any water from the fuel filter (Section 4)
Every 10 000 miles (15 000 km) or

12
months - whichever comes first ill addition lo tho Items listed above, cany out the following; D Check the operation of the brake warning lamp J (Section 5) Check the front brake pads for wear (Section 6) :-G Check the underbody and sealant for damage j" (Section 7) n Hose and fluid leak check (Section 8) 0 Check the condition of the exhaust system and its 1 mountings (Section 9) -D Check the condition of the driveshaft gaiters ", (Section 10) O Check and adjust the idle speed (Section 11) ;0 Renew (he fuel filter (Section 12) J] Renew the air filter element (Section 13) L) Renew the pollen filter (Section 14) •• Check the steering and suspension components • for condition and security (Section 15)
Every 20 000 miles (30 000 km) or

2
years - whichever comes first In addition to the Items listed above, cany out the following: (P Check and if necessary adjust the tension of the auxiliary drlvebeltfs) (Section 16) '• Check the freeplay and height of the clutch pedal " (Section 17) D Check and if necessary adjust the valve clearances (Section 18) Lubricate all hinges and locks (Section 19) • Check the headlight beam adjustment (Section 20) O Cany out a road test (Section 21)
Every 30 000 miles (45 000 km) or
3 years - whichever comes first In addition to the Items listed above, cany out the following: • Check and if necessary top-up the manual transmission oil level (Section 22)
Every 40 000 miles (60 000 km) or
4 years - whichever comes first In addition to the items listed above, cany out the following: • Check the rear brake shoes for wear (Section 23) • Renew the timing belt (Section 24)'
•Note: Although the normal interval for timing belt renewal is 70 000 miles (ids 000 km), it is strongly recommended that the belt Is renewed at 40 000 miles (60 000 km) on vehicles which are subjected to intensive use, le. mainly short Journeys or a lot of stop-start driving. The actual bait renewal interval Is therefore very much up to the Individual owner, but bear in mind that sevefe engine damage will result if the belt breaks.
Every 60 000 miles (90 000 km) or
6 years - whichever comes first In addition to the Items listed above, cany out the following: • Check the condition and operation of the emission control system components (Section 25)
Every 80 000 miles (120 000 km) • Renew the manual transmission oil (Section 26)
Every 2 years
(regardless of mileage) • Renew the engine coolant (Section 27) • Renew the brake fluid (Section 28)

1B«12 Every 20 000 miles - diesel models
21 Road test
Instruments and electrical equipment 1 Check the operation of atl instruments and electrical equipment. 2 Make sure that all instruments read correctly, and switch on all electrical equipment rn turn, to check that It functions properly. Steering and suspension 3 Check for any abnormalities in the steering, suspension, handling or road feel. 4 Drive the vehicle, and check that there are no unusual vibrations or noises. 5 Check that the steering feete positive, with no excessive sloppiness, or roughness, and check for any suspension noises when cornering and driving over bumps. Drivetrain 6 Check (he performance of the engine, clutch, transmission and driveshafts.
7 Listen for any unusual noises from the engine, clutch and transmission. 8 Make sure that the engine runs smoothly when Idling, and that there is no hesitation when accelerating. 9 Check that the clutch action is smooth and progressive, that tho drive is taken up smoothly, and that the pedal travel Is not excessive. Also listen for any noises when the clutch pedal is depressed. 10 Check that all gears can be engaged smoothly without noise, and that the gear lever action Is not abnormally vague or notchy. 11 Listen for a metallic clicking sound from ihe front of the vehicle, as the vehicle « driven slowly In a circle with the steering on full-lock. Carry out this check In both directions, if a clicking noise is heard, this Indicates wear in a driveshaft |oinl, in which case renew the joint if necessary.
Check the braking system 12 Make sure that the vehicle does not pull to one side when braking, and that the wheels do not lock prematurely when braking hard.
13 Check that there Is no vibration through the steering when braking. 14 Check that the handbrake operates correctiy without excessive movement of th« lever, end that it holds the vehicle stationery on a slope. 15 Test the operation of the brake servo unit as follows. With the engine off, depress the footbrake four or five times to exhaust the vacuum. Hold the brake pedal depressed, then start the engine. As the engine starts, there should be a noticeable give In the brake pedal as vacuum builds up. Allow the engine to run for at least two minutes, and then switch it off. If the brake pedal is depressed now, it should be possible to detect a hiss from the servo es the pedal is depressed. After about four or five applications, no fimher hissing should be heard, and the pedal should feel considerably harder. Note: The vacuum for the servo unit is provided by the vacuum pump mounted on the left-hand end of t/ie cylinder head.
Every 30 000 miles (45 000 km) or 3 years
22 Manual transmission oil level check ;5§
1 Park the vehicle on a level surface. If possible over an inspection pit or on a ramp as the filler/level plug is best reached from under Ihe engine compartment. The oil level must be checked before the car Is driven, or at least 5 minutes after the engine has been switched off. If the oil is checked Immediately after driving the car. some of the oil will remain distnbuted around the transmission compo-nents, resulting In an inaccurate level reading. 2 Wipe clean the area around the filler/level plug, which is situated on tho front of the
transmission (see illustration). Using an Allen key. unscrew the plug and clean it. 3 The oil level should reach the lower edge of the filler/level hole. A certain amount of oil will have gathered behind the filler/level plug, and will trickle out when it is removed; this does not necessarily Indicate that the level Is correct. To ensure that a true level Is established, wait until the Initial trickle has stopped, then add oil as necessary until a trickle of new oil can be seen emerging. The level will be correct when the flow ceases; use only good-quality oil of the specified type-Make sure that the vehicle Is completely level when checking the level and do not overfill. 4 When the level is correct refit and tighten the plug and wipe away any spilt oil.
22.2 Transmission filler/level plug location
Every 40 000 miles (60 000 km) or 4 years
23 Rear brake shoe check
1 Chock the front wheels then jack up the rear of the car and support It on axle stands (see Jacking and Vehicle Support), Remove the rear roadwhecla. 2 Using the inspection hole at the edge ot the brake drum, check that the linings are not worn below the minimum thickness given In the Spec ifi cat Ions (see Illustration). If necessary use a torch. 3 If the friction material on any shoe is worn down to the specified minimum thickness or iess. all four shoes must be renewed as a set, 4 At the same time check for signs of brake fluid leakage. 5 For a comprehensive check, the brake
drum should be removed and cleaned. This will allow the wheel cylinders to be checked, and the condition of the brake drum itself to be fully examined (see Chapter 9). 8 Refit the rubber plugs then lower the car to the ground.
24 Timing belt renewal
Refer to Chapter 2C. Note: Although the normal interval for timing belt
ranees/a!
is 70 000
mHes
(105 000
km),
it is strong recommended that the interval is reduced on vehicles which are subjected to intensive use, ie, mainly short journeys or a lot of stop-start driving. The actual belt renewal interval is therefore very much up to tho individual owner.
That being said, it is highly recommended to err on the side of safety, and renew (he belt at
this
earlier interval, bearing in mind the drastic consequences resulting from belt fetfure.
23.2 Check the thickness of the shoe friction material through the hole on the edge of the drum (arrowed)

Maintenance procedures - diesel models 1B.13
Every 60 000 miles (90 000 km) or 6 years
Refer to Chapter 40. A full chock of the 26 Emissions control systems emissions control systems must be made by a check Fiat dealer.
Every 80 000 miles (120 000 km)
26 Manual transmission ,v->> oil renewal K
1 Pak the vehicle on a level surface, if possible over an inspection pit or on a ramp as the filer/level and drain plugs are accessed from
under the
engine compartment, ff necessary tack up Ihe vehicle and support on axle stands (see Jacking and
vehicle
support). 2
Wipe
clean the area around the filler/! a vol and vain plugs, which are situated on the front and bottom of the transmission (see Illustration}.
3 Using an Allen key, unscrew the fillor/level plug and clean it. 4 Position a suitable container beneath the transmission, then use the Allen key to unscrew the drain plug. Allow the oil to completely dram. 5 Wipe clean the drain plug then refit and tighten It. 6 Fill the transmission with the correct grade and quantity of oil, referring to Section 22 when checking the level. Refit and tighten the filler/level plug. 7 Where applicable lower the vehicle to the ground. 26.2 Transmission drain plug location (viewed from undor tho vohlcle)
Every 2 years (regardless of mileage)

27
Coolant renewal St I
Coo//ng system draining

A


Warning: Wait until the engine is coid before starting this procedure. Do not allow anti-fnue to come in contact with your skin, or with the painted surfaces of the vehicle.
Rinse
off spills immediately with plenty of water. Never leave antifreeze lying around fh an open container, or in a puddle in the driveway or on the garage floor. Children
and
pets are attracted by Its sweet smell,
bat
antifreeze can be fatal if ingested. 1 With the engine completely cold, cover the expansion tank cap with a wad of rag, and slowly turn the cap anti-clockwise to relieve the
pressure in the cooling system (a hissing sound will normally be heard). Wail until any pressure remaining in the system is released, then continue to turn the cap until it can be removed. 2 Position a suitable container beneath the radiator bottom hose connection, then release the retaining clip and ease the hose from the radiator stub (see Illustration), If the hose joint has not been disturbed for some time, it will be necessary to gently manipulate the hose to break the joint. Do not use excessive force, or the radiator stub could be damaged. Allow the coolant to drain into the container. 3 Certain models are fitted with cooling system bleed plugs, which should be opened to aid the draining process and help prevent airlocks. These are located on the heator Inlet hose and on the top right hand edge of the radiator (see Illustrations), ff the coolant has
been drained for a reason other than renewal, then provided It is clean and less than two years old, it can be re-used, though this is not recommended. 4 Once all the coolant has drained, reconnect the hose to the radiator and secure it in position with the retaining clip.
Cooling system flushing 5 If coolant renewal has been neglected, or if the antifreeze mixture has become diluted, then In time, the cooling system may gradually lose efficiency, as the coolant passages become restricted due to rust, scale deposits, and other sediment. The cooling system efficiency can be restored by flushing tho system clean. 6 The radiator should be (lushed independently of the engine, to avoid unnecessary contam-ination.
27.2 Disconnecting the radiator bottom hose to drain the coolant 27.3a Location of cooling system bleed plugs (arrowed) 27.3b Bleed screw located on the top right hand edge of the radiator

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.