engine overheat 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

MFuel filter choked (Chapter 1).
MFuel pump faulty, or delivery pressure low (Chapter 4).
MFuel tank vent blocked, or fuel pipes restricted (Chapter 4).
MFuel injection system fault (Chapter 4).
Engine lacks power
MFuel filter choked (Chapter 1).
MFuel pump faulty, or delivery pressure low (Chapter 4).
MUneven or low cylinder compressions (Chapter 2).
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).
MBrakes binding (Chapters 1 and 10).
MClutch slipping (Chapter 6).
Engine backfires
MVacuum leak at the throttle body, inlet manifold or associated
hoses (Chapter 4).
MFuel injection system fault (Chapter 4).
Oil pressure warning light illuminated with engine
running
MLow oil level, or incorrect oil grade (Chapter 1).
MFaulty oil pressure sensor (Chapter 2).
MWorn engine bearings and/or oil pump (Chapter 2).
MExcessively high engine operating temperature (Chapter 3).
MOil pressure relief valve defective (Chapter 2).
MOil pick-up strainer clogged (Chapter 2).
Note:Low oil pressure in a high-mileage engine at tickover is not
necessarily a cause for concern. Sudden pressure loss at speed is far
more significant. In any event, check the gauge or warning light sender
before condemning the engine.
Engine runs-on after switching off
MExcessive carbon build-up in engine (Chapter 2).
MExcessively high engine operating temperature (Chapter 3).
Engine noises
Pre-ignition (pinking) or knocking during acceleration or
under load
MIgnition timing incorrect/ignition system fault (Chapters 1 and 5).
MIncorrect grade of spark plug (Chapter 1).
MIncorrect grade of fuel (Chapter 1).
MVacuum leak at throttle body, inlet manifold or associated hoses
(Chapter 4).
MExcessive carbon build-up in engine (Chapter 2).
MFuel injection system fault (Chapter 4).
Whistling or wheezing noises
MLeaking inlet manifold or throttle body gasket (Chapter 4).
MLeaking exhaust manifold gasket (Chapter 4).
MLeaking vacuum hose (Chapters 4 and 10).
MBlowing cylinder head gasket (Chapter 2).
Tapping or rattling noises
MWorn valve gear, timing chain, camshaft or hydraulic tappets
(Chapter 2).
MAncillary component fault (water pump, alternator, etc) (Chapters 3, 5)
Knocking or thumping noises
MWorn big-end bearings (regular heavy knocking, perhaps less
under load) (Chapter 2).
MWorn main bearings (rumbling and knocking, perhaps worsening
under load) (Chapter 2).
MPiston slap (most noticeable when cold) (Chapter 2).
MAncillary component fault (water pump, alternator, etc) (Chapters 3, 5)
Overheating
MAuxiliary drivebelt broken or incorrectly adjusted (Chapter 1).
MInsufficient coolant in system (Chapter 1).
MThermostat faulty (Chapter 3).
MRadiator core blocked, or grille restricted (Chapter 3).
MElectric cooling fan or thermostatic switch faulty (Chapter 3).
MViscous-coupled fan faulty (Chapter 3).
MIgnition timing incorrect, or ignition system fault (Chapters 1 and 5).
MInaccurate temperature gauge sender unit (Chapter 3).
MAirlock in cooling system (Chapter 3).
Overcooling
MThermostat faulty (Chapter 3).
MInaccurate temperature gauge sender unit (Chapter 3).
External coolant leakage
MDeteriorated or damaged hoses or hose clips (Chapter 1).
MRadiator core or heater matrix leaking (Chapter 3).
MPressure cap faulty (Chapter 3).
MWater pump internal seal leaking (Chapter 3).
MWater pump-to-block seal leaking (Chapter 3).
MBoiling due to overheating (Chapter 3).
MCore plug leaking (Chapter 2).
Internal coolant leakage
MLeaking cylinder head gasket (Chapter 2).
MCracked cylinder head or cylinder block (Chapter 2).
Corrosion
MInfrequent draining and flushing (Chapter 1).
MIncorrect coolant mixture or inappropriate coolant type (Chapter 1).
Fault diagnosisREF•13
REF
Cooling system
Excessive fuel consumption
MAir filter element dirty or clogged (Chapter 1).
MFuel injection system fault (Chapter 4).
MIgnition timing incorrect or ignition system fault (Chapters 1 and 5).
MBrakes binding (Chapter 10).
MTyres under-inflated (Chapter 1).
Fuel leakage and/or fuel odour
MDamaged fuel tank, pipes or connections (Chapters 1 and 4).
Excessive noise or fumes from exhaust system
MLeaking exhaust system or manifold joints (Chapters 1 and 4).
MLeaking, corroded or damaged silencers or pipe (Chapters 1 and 4).
MBroken mountings causing body or suspension contact (Chapter 4).
Fuel and exhaust systems