stop start FORD SIERRA 1992 2.G Reference Workshop Manual

The vehicle owner who does his or her own maintenance according
to the recommended service schedules should not have to use this
section of the manual very often. Modern component reliability is such
that, provided those items subject to wear or deterioration are
inspected or renewed at the specified intervals, sudden failure is
comparatively rare. Faults do not usually just happen as a result of
sudden failure, but develop over a period of time. Major mechanical
failures in particular are usually preceded by characteristic symptoms
over hundreds or even thousands of miles. Those components which
do occasionally fail without warning are often small and easily carried
in the vehicle.
With any fault-finding, the first step is to decide where to begin
investigations. Sometimes this is obvious, but on other occasions, alittle detective work will be necessary. The owner who makes half a
dozen haphazard adjustments or replacements may be successful in
curing a fault (or its symptoms), but will be none the wiser if the fault
recurs, and ultimately may have spent more time and money than was
necessary. A calm and logical approach will be found to be more
satisfactory in the long run. Always take into account any warning
signs or abnormalities that may have been noticed in the period
preceding the fault - power loss, high or low gauge readings, unusual
smells, etc - and remember that failure of components such as fuses or
spark plugs may only be pointers to some underlying fault.
The pages which follow provide an easy-reference guide to the more
common problems which may occur during the operation of the
vehicle. These problems and their possible causes are grouped under
Fault diagnosisREF•11
REF
Engine
MEngine fails to rotate when attempting to start
MStarter motor turns engine slowly
MEngine rotates, but will not start
MEngine difficult to start when cold
MEngine difficult to start when hot
MStarter motor noisy or excessively-rough in engagement
MEngine starts, but stops immediately
MEngine idles erratically
MEngine misfires at idle speed
MEngine misfires throughout the driving speed range
MEngine hesitates on acceleration
MEngine stalls
MEngine lacks power
MEngine backfires
MOil pressure warning light illuminated with engine running
MEngine runs-on after switching off
MEngine noises
Cooling system
MOverheating
MOvercooling
MExternal coolant leakage
MInternal coolant leakage
MCorrosion
Fuel and exhaust systems
MExcessive fuel consumption
MFuel leakage and/or fuel odour
MExcessive noise or fumes from exhaust system
Clutch
MPedal travels to floor - no pressure or very little resistance
MClutch fails to disengage (unable to select gears)
MClutch slips (engine speed increases; no increase in vehicle speed)
MJudder as clutch is engaged
MNoise when depressing or releasing clutch pedal
Manual gearbox
MNoisy in neutral with engine running
MNoisy in one particular gear
MDifficulty engaging gears
MJumps out of gear
MVibration
MLubricant leaks
Automatic transmission
MFluid leakage
MTransmission fluid brown, or has burned smellMGeneral gear selection problems
MTransmission will not downshift (kickdown) with acceleration
MEngine will not start in any gear, or starts in gears other than Park
or Neutral
MTransmission slips, shifts roughly, is noisy, or has no drive in forward
or reverse gears
Propeller shaft
MClunking or knocking noise when taking up drive
MVibration when accelerating or decelerating
Final drive and driveshafts
MExcessive final drive noise
MOil leakage from final drive
MGrating, knocking or vibration from driveshafts
Braking system
MVehicle pulls to one side under braking
MNoise (grinding or high-pitched squeal) when brakes applied
MExcessive brake pedal travel
MBrake pedal feels spongy when depressed
MExcessive brake pedal effort required to stop vehicle
MJudder felt through brake pedal or steering wheel when braking
MPedal pulsates when braking hard
MBrakes binding
MRear wheels locking under normal braking
Suspension and steering systems
MVehicle pulls to one side
MWheel wobble and vibration
MExcessive pitching and/or rolling around corners, or during braking
MWandering or general instability
MExcessively-stiff steering
MExcessive play in steering
MLack of power assistance
MTyre wear excessive
Electrical system
MBattery will not hold a charge for more than a few days
MIgnition/no-charge warning light remains on with engine running
MIgnition/no-charge warning light fails to come on
MLights inoperative
MInstrument readings inaccurate or erratic
MHorn inoperative, or unsatisfactory in operation
MWindscreen/tailgate wipers inoperative, or unsatisfactory in operation
MWindscreen/tailgate washers inoperative, or unsatisfactory in
operation
MElectric windows inoperative, or unsatisfactory in operation
MCentral locking system inoperative, or unsatisfactory in operation
Introduction

headings denoting various components or systems, such as Engine,
Cooling system, etc. The Chapter and/or Section which deals with the
problem is also shown in brackets. Whatever the fault, certain basic
principles apply. These are as follows:
Verify the fault. This is simply a matter of being sure that you know
what the symptoms are before starting work. This is particularly
important if you are investigating a fault for someone else, who may
not have described it very accurately.
Don’t overlook the obvious. For example, if the vehicle won’t start, is
there fuel in the tank? (Don’t take anyone else’s word on this particular
point, and don’t trust the fuel gauge either!) If an electrical fault is
indicated, look for loose or broken wires before digging out the test
gear.Cure the disease, not the symptom. Substituting a flat battery with a
fully-charged one will get you off the hard shoulder, but if the
underlying cause is not attended to, the new battery will go the same
way. Similarly, changing oil-fouled spark plugs for a new set will get
you moving again, but remember that the reason for the fouling (if it
wasn’t simply an incorrect grade of plug) will have to be established
and corrected.
Don’t take anything for granted. Particularly, don’t forget that a
“new” component may itself be defective (especially if it’s been rattling
around in the boot for months), and don’t leave components out of a
fault diagnosis sequence just because they are new or recently-fitted.
When you do finally diagnose a difficult fault, you’ll probably realise
that all the evidence was there from the start.
Engine fails to rotate when attempting to start
MBattery terminal connections loose or corroded (Chapter 1).
MBattery discharged or faulty (Chapter 5).
MBroken, loose or disconnected wiring in the starting circuit (Chapter 5).
MDefective starter solenoid or switch (Chapter 5).
MDefective starter motor (Chapter 5).
MStarter pinion or flywheel/driveplate ring gear teeth loose or broken
(Chapters 2 or 5).
MEngine earth strap broken or disconnected.
Starter motor turns engine slowly
MPartially-discharged battery (recharge, use jump leads, or push start)
(Chapter 5).
MBattery terminals loose or corroded (Chapter 1).
MBattery earth to body defective (Chapter 5).
MEngine earth strap loose.
MStarter motor (or solenoid) wiring loose (Chapter 5).
MStarter motor internal fault (Chapter 5).
Engine rotates, but will not start
MFuel pump inertia switch tripped (electric pump) (Chapter 4).
MFuel tank empty.
MBattery discharged (engine rotates slowly) (Chapter 5).
MBattery terminal connections loose or corroded (Chapter 1).
MIgnition components damp or damaged (Chapters 1 and 5).
MBroken, loose or disconnected wiring in the ignition circuit (Chapters 1
and 5).
MWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
MFuel injection system fault (Chapter 4).
MMajor mechanical failure (eg broken timing chain) (Chapter 2).
Engine difficult to start when cold
MBattery discharged (Chapter 5).
MBattery terminal connections loose or corroded (Chapter 1).
MWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
MFuel injection system fault (Chapter 4).
MOther ignition system fault (Chapters 1 and 5).
MLow cylinder compressions (Chapter 2).
Engine difficult to start when hot
MAir filter element dirty or clogged (Chapter 1).
MFuel injection system fault (Chapter 4).
MLow cylinder compressions (Chapter 2).
Starter motor noisy or excessively-rough in
engagement
MStarter pinion or flywheel/driveplate ring gear teeth loose or broken
(Chapters 2 or 5).
MStarter motor mounting bolts loose or missing (Chapter 5).
MStarter motor internal components worn or damaged (Chapter 5).
Engine starts, but stops immediately
MLoose or faulty electrical connections in the ignition circuit
(Chapters 1 and 5).
MVacuum leak at the throttle body or inlet manifold (Chapter 4).
MFuel injection system fault (Chapter 4).
Engine idles erratically
MIncorrectly-adjusted idle speed (Chapter 4).
MAir filter element clogged (Chapter 1).
MVacuum leak at the throttle body, inlet manifold or associated
hoses (Chapter 4).
MWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
MUneven or low cylinder compressions (Chapter 2).
MCamshaft lobes worn (Chapter 2).
MFuel injection system fault (Chapter 4).
Engine misfires at idle speed
MWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
MFaulty spark plug HT leads (Chapter 5).
MVacuum leak at the throttle body, inlet manifold or associated
hoses (Chapter 4).
MFuel injection system fault (Chapter 4).
MDistributor cap cracked or tracking internally, where applicable
(Chapter 5).
MUneven or low cylinder compressions (Chapter 2).
MDisconnected, leaking, or perished crankcase ventilation hoses
(Chapter 4).
Engine misfires throughout the driving speed range
MFuel filter choked (Chapter 1).
MFuel pump faulty, or delivery pressure low (Chapter 4).
MFuel tank vent blocked, or fuel pipes restricted (Chapter 4).
MVacuum leak at the throttle body, inlet manifold or associated
hoses (Chapter 4).
MWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
MFaulty spark plug HT leads (Chapter 5).
MDistributor cap cracked or tracking internally, where applicable
(Chapter 5).
MFaulty ignition coil (Chapter 5).
MUneven or low cylinder compressions (Chapter 2).
MFuel injection system fault (Chapter 4).
Engine hesitates on acceleration
MWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
MVacuum leak at the throttle body, inlet manifold or associated
hoses (Chapter 4).
MFuel injection system fault (Chapter 4).
Engine stalls
MVacuum leak at the throttle body, inlet manifold or associated
hoses (Chapter 4).
REF•12Fault diagnosis
Engine

Excessive final drive noise
MOil level low, or incorrect grade (Chapter 1)
MWorn bearings (Chapter 9)
MWorn or badly adjusted crownwheel and pinion (Chapter 9)
MLoose or deteriorated final drive mountings (Chapter 9)
Oil leakage from final drive
MPinion or output flange oil seal leaking (Chapter 9)MRear cover leaking (Chapter 9)
MCover or casing cracked (Chapter 9)
Grating, knocking or vibration from driveshafts
MFlange screws loose (Chapter 9)
MCV joints worn (Chapter 9)
MDriveshaft bent (Chapter 9)
Note:Before assuming that a brake problem exists, make sure that the
tyres are in good condition and correctly inflated, that the front wheel
alignment is correct, and that the vehicle is not loaded with weight in an
unequal manner. Apart from checking the condition of all pipe and
hose connections, any faults occurring on the anti-lock braking system
should be referred to a Ford dealer for diagnosis.
Vehicle pulls to one side under braking
MWorn, defective, damaged or contaminated front or rear brake
pads on one side (Chapters 1 and 10).
MSeized or partially-seized front or rear brake caliper piston
(Chapter 10).
MA mixture of brake pad lining materials fitted between sides
(Chapter 10).
MBrake caliper mounting bolts loose (Chapter 10).
MWorn or damaged steering or suspension components (Chapters 1
and 11).
Noise (grinding or high-pitched squeal) when brakes
applied
MBrake pad friction lining material worn down to metal backing
(Chapters 1 and 10).
MExcessive corrosion of brake disc - may be apparent after the
vehicle has been standing for some time (Chapters 1 and 10).
Excessive brake pedal travel
MFaulty master cylinder (Chapter 10).
MAir in hydraulic system (Chapter 10).MFaulty vacuum servo unit (Chapter 10).
Brake pedal feels spongy when depressed
MAir in hydraulic system (Chapter 10).
MDeteriorated flexible rubber brake hoses (Chapters 1 and 10).
MMaster cylinder mountings loose (Chapter 10).
MFaulty master cylinder (Chapter 10).
Excessive brake pedal effort required to stop vehicle
MFaulty vacuum servo unit (Chapter 10).
MDisconnected, damaged or insecure brake servo vacuum hose
(Chapters 1 and 10).
MPrimary or secondary hydraulic circuit failure (Chapter 10).
MSeized brake caliper piston(s) (Chapter 10).
MBrake pads incorrectly fitted (Chapter 10).
MIncorrect grade of brake pads fitted (Chapter 10).
MBrake pads contaminated (Chapter 10).
Judder felt through brake pedal or steering wheel
when braking
MExcessive run-out or distortion of brake disc(s) (Chapter 10).
MBrake pad linings worn (Chapters 1 and 10).
MBrake caliper mounting bolts loose (Chapter 10).
MWear in suspension or steering components or mountings
(Chapters 1 and 11).
Pedal pulsates when braking hard
MNormal feature of ABS - no fault
Clunking or knocking noise when taking up drive
MWorn universal joints (Chapter 8).
MLoose flange bolt (Chapter 8).
Vibration when accelerating or decelerating
MWorn centre bearing or universal joints (Chapter 8).
MBent or distorted shaft (Chapter 8).
MDeteriorated rubber insulator on centre bearing ( Chapter 8)
Engine will not start in any gear, or starts in gears
other than Park or Neutral
MFaulty starter inhibitor switch (Chapter 7).
MIncorrect selector adjustment (Chapter 7).
Transmission slips, shifts roughly, is noisy, or has no
drive in forward or reverse gears
MThere are many probable causes for the above problems, but the
home mechanic should be concerned with only one possibility - fluid
level. Before taking the vehicle to a dealer or transmission specialist,
check the fluid level and condition of the fluid as described in Chapter
1. Correct the fluid level as necessary, or change the fluid and filter if
needed. If the problem persists, professional help will be necessary.
Fault diagnosisREF•15
REF
Propeller shaft
Final drive and driveshafts
Braking system

Glossary of Technical termsREF•21
REF
JJump startStarting the engine of a vehicle
with a discharged or weak battery by
attaching jump leads from the weak battery to
a charged or helper battery.
LLoad Sensing Proportioning Valve (LSPV)A
brake hydraulic system control valve that
works like a proportioning valve, but also
takes into consideration the amount of weight
carried by the rear axle.
LocknutA nut used to lock an adjustment
nut, or other threaded component, in place.
For example, a locknut is employed to keep
the adjusting nut on the rocker arm in
position.
LockwasherA form of washer designed to
prevent an attaching nut from working loose.
MMacPherson strutA type of front
suspension system devised by Earle
MacPherson at Ford of England. In its original
form, a simple lateral link with the anti-roll bar
creates the lower control arm. A long strut - an
integral coil spring and shock absorber - is
mounted between the body and the steering
knuckle. Many modern so-called MacPherson
strut systems use a conventional lower A-arm
and don’t rely on the anti-roll bar for location.
MultimeterAn electrical test instrument with
the capability to measure voltage, current and
resistance.
NNOxOxides of Nitrogen. A common toxic
pollutant emitted by petrol and diesel engines
at higher temperatures.
OOhmThe unit of electrical resistance. One
volt applied to a resistance of one ohm will
produce a current of one amp.
OhmmeterAn instrument for measuring
electrical resistance.
O-ringA type of sealing ring made of a
special rubber-like material; in use, the O-ring
is compressed into a groove to provide the
sealing action.Overhead cam (ohc) engineAn engine with
the camshaft(s) located on top of the cylinder
head(s).
Overhead valve (ohv) engineAn engine with
the valves located in the cylinder head, but
with the camshaft located in the engine block.
Oxygen sensorA device installed in the
engine exhaust manifold, which senses the
oxygen content in the exhaust and converts
this information into an electric current. Also
called a Lambda sensor.
PPhillips screwA type of screw head having a
cross instead of a slot for a corresponding
type of screwdriver.
PlastigageA thin strip of plastic thread,
available in different sizes, used for measuring
clearances. For example, a strip of Plastigage
is laid across a bearing journal. The parts are
assembled and dismantled; the width of the
crushed strip indicates the clearance between
journal and bearing.
Propeller shaftThe long hollow tube with
universal joints at both ends that carries
power from the transmission to the differential
on front-engined rear wheel drive vehicles.
Proportioning valveA hydraulic control
valve which limits the amount of pressure to
the rear brakes during panic stops to prevent
wheel lock-up.
RRack-and-pinion steeringA steering system
with a pinion gear on the end of the steering
shaft that mates with a rack (think of a geared
wheel opened up and laid flat). When the
steering wheel is turned, the pinion turns,
moving the rack to the left or right. This
movement is transmitted through the track
rods to the steering arms at the wheels.
RadiatorA liquid-to-air heat transfer device
designed to reduce the temperature of the
coolant in an internal combustion engine
cooling system.
RefrigerantAny substance used as a heat
transfer agent in an air-conditioning system.
R-12 has been the principle refrigerant for
many years; recently, however, manufacturers
have begun using R-134a, a non-CFC
substance that is considered less harmful tothe ozone in the upper atmosphere.
Rocker armA lever arm that rocks on a shaft
or pivots on a stud. In an overhead valve
engine, the rocker arm converts the upward
movement of the pushrod into a downward
movement to open a valve.
RotorIn a distributor, the rotating device
inside the cap that connects the centre
electrode and the outer terminals as it turns,
distributing the high voltage from the coil
secondary winding to the proper spark plug.
Also, that part of an alternator which rotates
inside the stator. Also, the rotating assembly
of a turbocharger, including the compressor
wheel, shaft and turbine wheel.
RunoutThe amount of wobble (in-and-out
movement) of a gear or wheel as it’s rotated.
The amount a shaft rotates “out-of-true.” The
out-of-round condition of a rotating part.
SSealantA liquid or paste used to prevent
leakage at a joint. Sometimes used in
conjunction with a gasket.
Sealed beam lampAn older headlight design
which integrates the reflector, lens and
filaments into a hermetically-sealed one-piece
unit. When a filament burns out or the lens
cracks, the entire unit is simply replaced.
Serpentine drivebeltA single, long, wide
accessory drivebelt that’s used on some
newer vehicles to drive all the accessories,
instead of a series of smaller, shorter belts.
Serpentine drivebelts are usually tensioned by
an automatic tensioner.
ShimThin spacer, commonly used to adjust
the clearance or relative positions between
two parts. For example, shims inserted into or
under bucket tappets control valve
clearances. Clearance is adjusted by
changing the thickness of the shim.
Slide hammerA special puller that screws
into or hooks onto a component such as a
shaft or bearing; a heavy sliding handle on the
shaft bottoms against the end of the shaft to
knock the component free.
SprocketA tooth or projection on the
periphery of a wheel, shaped to engage with a
chain or drivebelt. Commonly used to refer to
the sprocket wheel itself.
Starter inhibitor switchOn vehicles with an
O-ring
Serpentine drivebelt
Plastigage

REF•22Glossary of Technical terms
automatic transmission, a switch that
prevents starting if the vehicle is not in Neutral
or Park.
StrutSee MacPherson strut.
TTappetA cylindrical component which
transmits motion from the cam to the valve
stem, either directly or via a pushrod and
rocker arm. Also called a cam follower.
ThermostatA heat-controlled valve that
regulates the flow of coolant between the
cylinder block and the radiator, so maintaining
optimum engine operating temperature. A
thermostat is also used in some air cleaners in
which the temperature is regulated.
Thrust bearingThe bearing in the clutch
assembly that is moved in to the release levers
by clutch pedal action to disengage the
clutch. Also referred to as a release bearing.
Timing beltA toothed belt which drives the
camshaft. Serious engine damage may result
if it breaks in service.
Timing chainA chain which drives the
camshaft.
Toe-inThe amount the front wheels are
closer together at the front than at the rear. On
rear wheel drive vehicles, a slight amount of
toe-in is usually specified to keep the front
wheels running parallel on the road by
offsetting other forces that tend to spread the
wheels apart.
Toe-outThe amount the front wheels are
closer together at the rear than at the front. Onfront wheel drive vehicles, a slight amount of
toe-out is usually specified.
ToolsFor full information on choosing and
using tools, refer to the Haynes Automotive
Tools Manual.
TracerA stripe of a second colour applied to
a wire insulator to distinguish that wire from
another one with the same colour insulator.
Tune-upA process of accurate and careful
adjustments and parts replacement to obtain
the best possible engine performance.
TurbochargerA centrifugal device, driven by
exhaust gases, that pressurises the intake air.
Normally used to increase the power output
from a given engine displacement, but can
also be used primarily to reduce exhaust
emissions (as on VW’s “Umwelt” Diesel
engine).
UUniversal joint or U-jointA double-pivoted
connection for transmitting power from a
driving to a driven shaft through an angle. A U-
joint consists of two Y-shaped yokes and a
cross-shaped member called the spider.
VValveA device through which the flow of
liquid, gas, vacuum, or loose material in bulk
may be started, stopped, or regulated by a
movable part that opens, shuts, or partiallyobstructs one or more ports or passageways.
A valve is also the movable part of such a
device.
Valve clearanceThe clearance between the
valve tip (the end of the valve stem) and the
rocker arm or tappet. The valve clearance is
measured when the valve is closed.
Vernier caliperA precision measuring
instrument that measures inside and outside
dimensions. Not quite as accurate as a
micrometer, but more convenient.
ViscosityThe thickness of a liquid or its
resistance to flow.
VoltA unit for expressing electrical “pressure”
in a circuit. One volt that will produce a current
of one ampere through a resistance of one
ohm.
WWeldingVarious processes used to join metal
items by heating the areas to be joined to a
molten state and fusing them together. For
more information refer to the Haynes
Automotive Welding Manual.
Wiring diagramA drawing portraying the
components and wires in a vehicle’s electrical
system, using standardised symbols. For
more information refer to the Haynes
Automotive Electrical and Electronic Systems
Manual.