SAAB 9000. Manual - part 57

Fault Finding

REF•5

Engine fails to rotate when attempting to start
Engine rotates, but will not start
Engine difficult to start when cold
Engine difficult to start when hot
Starter motor noisy or excessively-rough in engagement

Engine starts, but stops immediately

Engine idles erratically

Engine misfires at idle speed

Engine misfires throughout the driving speed range
Engine hesitates on acceleration
Engine stalls
Engine lacks power
Engine backfires
Oil pressure warning light illuminated with engine running
Engine runs-on after switching off
Engine noises

Cooling system 2

Overheating
Overcooling
External coolant leakage
Internal coolant leakage
Corrosion

Fuel and exhaust systems 3

Excessive fuel consumption
Fuel leakage and/or fuel odour
Excessive noise or fumes from exhaust system

Clutch 4

Pedal travels to floor - no pressure or very little resistance
Clutch fails to disengage (unable to select gears)
Clutch slips (engine speed increases, with no increase in vehicle

speed)

Judder as clutch is engaged
Noise when depressing or releasing clutch pedal

Manual transmission 5

Noisy in neutral with engine running
Noisy in one particular gear
Difficulty engaging gears
Jumps out of gear
Vibration
Lubricant leaks

Automatic transmission

Fluid leakage

Transmission fluid brown, or has burned smell

General gear selection problems
Transmission will not downshift (kickdown) with accelerator fully

depressed

Engine will not start in any gear, or starts in gears other than Park

or Neutral

Transmission slips, shifts roughly, is noisy, or has no drive in

forward or reverse gears

Driveshafts 7

Clicking or knocking noise on turns (at slow speed on full-lock)
Vibration when accelerating or decelerating

Braking system 8

Vehicle pulls to one side under braking
Noise (grinding or high-pitched squeal) when brakes applied
Excessive brake pedal travel
Brake pedal feels spongy when depressed
Excessive brake pedal effort required to stop vehicle
Judder felt through brake pedal or steering wheel when braking
Brakes binding
Rear wheels locking under normal braking

Suspension and steering systems 9

Vehicle pulls to one side
Wheel wobble and vibration
Excessive pitching and/or rolling around corners, or during

braking

Wandering or general instability
Excessively-stiff steering
Excessive play in steering
Lack of power assistance
Tyre wear excessive

Electrical system 10

Battery will not hold a charge for more than a few days
Ignition/no-charge warning light remains illuminated with engine

running

Ignition/no-charge warning light fails to come on
Lights inoperative
Instrument readings inaccurate or erratic
Horn inoperative, or unsatisfactory in operation
Windscreen/tailgate wipers inoperative, or unsatisfactory in

operation

Windscreen/tailgate washers inoperative, or unsatisfactory in

operation

Electric windows inoperative, or unsatisfactory in operation
Central locking system inoperative, or unsatisfactory in operation

Introduction

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, a

little 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

REF•6

Fault Finding

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.

1 Engine

Engine fails to rotate when attempting to start

Battery terminal connections loose or corroded (Chapter 1).
Battery discharged or faulty (Chapter 5A).
Broken, loose or disconnected wiring in the starting circuit (Chap-

ter

5A).

Defective starter solenoid or switch (Chapter 5A).
Defective starter motor (Chapter 5A).
Starter pinion or flywheel/driveplate ring gear teeth loose or broken

(Chapters 2A or 5A).

Engine earth strap broken or disconnected (Chapter 5A).

Starter motor turns engine slowly

Partially-discharged battery (recharge, use jump leads, or push

start) (Chapter 5A).

Battery terminals loose or corroded (Chapter 1).
Battery earth to body defective (Chapter 5A).
Engine earth strap loose (Chapter 5A).
Starter motor (or solenoid) wiring loose (Chapter 5A).
Starter motor internal fault (Chapter 5A).

Engine rotates, but will not start

Fuel tank empty.
Battery discharged (engine rotates slowly) (Chapter 5A).
Battery terminal connections loose or corroded (Chapter 1).
Ignition components damp or damaged (Chapters 1 and 5B).
Broken, loose or disconnected wiring in the ignition circuit

(Chapters 1 and 5B).

Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).
Fuel injection system fault (Chapter 4A).
Major mechanical failure (eg broken timing chain) (Chapter 2A).

Engine difficult to start when cold

Battery discharged (Chapter 5A).
Battery terminal connections loose or corroded (Chapter 1).
Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).
Fuel injection system fault (Chapter 4A).
Other ignition system fault (Chapters 1 and 5B).
Low cylinder compressions (Chapter 2A).

Engine difficult to start when hot

Air filter element dirty or clogged (Chapter 1).
Fuel injection system fault (Chapter 4A).
Low cylinder compressions (Chapter 2A).

Starter motor noisy or excessively-rough in

engagement

Starter pinion or flywheel/driveplate ring gear teeth loose or broken

(Chapters 2A or 5A).

Starter motor mounting bolts loose or missing (Chapter 5A).
Starter motor internal components worn or damaged (Chapter 5A).

Engine starts, but stops immediately

Loose or faulty electrical connections in the ignition circuit

(Chapters 1 and 5B).

Vacuum leak at the throttle body or inlet manifold (Chapter 4A).
Fuel injection system fault (Chapter 4A).

Engine idles erratically

Incorrectly-adjusted idle speed (Chapter 4A).
Air filter element clogged (Chapter 1).
Vacuum leak at the throttle body, inlet manifold or associated hoses

(Chapter 4A or 4B).

Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).
Uneven or low cylinder compressions (Chapter 2A).
Camshaft lobes worn (Chapter 2A).
Fuel injection system fault (Chapter 4A).

Engine misfires at idle speed

Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).
Faulty spark plug HT leads or Dl cartridge as applicable (Chapter 1).
Vacuum leak at the throttle body, inlet manifold or associated hoses

(Chapter 4A or 4B).

Fuel injection system fault (Chapter 4A).
Distributor cap cracked or tracking internally, where applicable

(Chapter 1).

Uneven or low cylinder compressions (Chapter 2A).
Disconnected, leaking, or perished crankcase ventilation hoses

(Chapter 4B).

Engine misfires throughout the driving speed range

Fuel filter choked (Chapter 1).
Fuel pump faulty, or delivery pressure low (Chapter 4A).
Fuel tank vent blocked, or fuel pipes restricted (Chapter 4A).
Vacuum leak at the throttle body, inlet manifold or associated hoses

(Chapter 4A).

Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).
Faulty spark plug HT leads or Dl cartridge, as applicable (Chap-

ter 1).

Distributor cap cracked or tracking internally, where applicable

(Chapter 1).

Faulty ignition coil (Chapter 5B).
Uneven or low cylinder compressions (Chapter 2A).
Fuel injection system fault (Chapter 4A).

Engine stalls

Vacuum leak at the throttle body, inlet manifold or associated hoses

(Chapter 4A or 4B).

Fuel filter choked (Chapter 1).
Fuel pump faulty, or delivery pressure low (Chapter 4A).
Fuel tank vent blocked, or fuel pipes restricted (Chapter 4A).
Fuel injection system fault (Chapter 4A).

Fault Finding

REF•7

Engine hesitates on acceleration

Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).

Vacuum leak at the throttle body, inlet manifold or associated hoses

(Chapter 4A or 4B).

Fuel injection system fault (Chapter 4A).

Engine lacks power

Fuel filter choked (Chapter 1).
Fuel pump faulty, or delivery pressure low (Chapter 4A).
Uneven or low cylinder compressions (Chapter 2A).
Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).
Vacuum leak at the throttle body, inlet manifold or associated hoses

(Chapter 4A or 4B).

Fuel injection system fault (Chapter 4A).

Faulty turbocharger, where applicable (Chapter 4A).
Brakes binding (Chapters 1 and 9).
Clutch slipping (Chapter 6).

Engine backfires

Vacuum leak at the throttle body, inlet manifold or associated hoses

(Chapter 4A or 4B).

Fuel injection system fault (Chapter 4A).

Oil pressure warning light illuminated with engine
running

Low oil level, or incorrect oil grade (Chapter 1).

Faulty oil pressure sensor (Chapter 2A).
Worn engine bearings and/or oil pump (Chapter 2A or 2B).
Excessively high engine operating temperature (Chapter 3).
Oil pressure relief valve defective (Chapter 2A).
Oil pick-up strainer clogged (Chapter 2A).
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.

2 Cooling system

Engine runs-on after switching off

Excessive carbon build-up in engine (Chapter 2A or 2B).
Excessively high engine operating temperature (Chapter 3).

Engine noises

Pre-ignition (pinking) or knocking during acceleration or
under load

Ignition timing incorrect/ignition system fault (Chapters 1 and 5B).
Incorrect grade of spark plug (Chapter 1).
Incorrect grade of fuel (Chapter 1).
Vacuum leak at throttle body, inlet manifold or associated hoses

(Chapter 4A or 4B).

Excessive carbon build-up in engine (Chapter 2A or 2B).
Fuel injection system fault (Chapter 4A).

Whistling or wheezing noises

Leaking inlet manifold or throttle body gasket (Chapter 4A).

Leaking exhaust manifold gasket (Chapter 4A).
Leaking vacuum hose (Chapters 4A, 4B and 9).
Blowing cylinder head gasket (Chapter 2A).

Tapping or rattling noises

Worn valve gear, timing chain, camshaft or hydraulic tappets

(Chapter 2A).

Ancillary component fault (water pump, alternator, etc) (Chapt-

ers

3, 5A, etc).

Knocking or thumping noises

Worn big-end bearings (regular heavy knocking, perhaps less under

load) (Chapter 2B).

Worn main bearings (rumbling and knocking, perhaps worsening

under load) (Chapter 2B).

Piston slap (most noticeable when cold) (Chapter 2B).

Ancillary component fault (water pump, alternator, etc) (Chapters 3,

5A,

etc).

Overheating

Auxiliary drivebelt broken - or, where applicable, incorrectly

adjusted (Chapter 1).

Insufficient coolant in system (Chapter 1).
Thermostat faulty (Chapter 3).
Radiator core blocked, or grille restricted (Chapter 3).
Electric cooling fan or thermostatic switch faulty (Chapter 3).
Pressure cap faulty (Chapter 3).
Ignition timing incorrect, or ignition system fault (Chapters 1

and

5B).

Inaccurate temperature gauge sender unit (Chapter 3).
Airlock in cooling system (Chapter 1).

Overcooling

Thermostat faulty (Chapter 3).
Inaccurate temperature gauge sender unit (Chapter 3).

External coolant leakage

Deteriorated or damaged hoses or hose clips (Chapter 1).
Radiator core or heater matrix leaking (Chapter 3).
Pressure cap faulty (Chapter 3).
Water pump internal seal leaking (Chapter 3).
Water pump-to-block O-ring or housing gasket leaking (Chapter 3).
Boiling due to overheating (Chapter 3).
Core plug leaking (Chapter 2B).

Internal coolant leakage

Leaking cylinder head gasket (Chapter 2A).
Cracked cylinder head or cylinder block (Chapter 2A or 2B).

Corrosion

Infrequent draining and flushing (Chapter 1).
Incorrect coolant mixture or inappropriate coolant type (Chapter 1).

3 Fuel and exhaust systems

Excessive fuel consumption

Air filter element dirty or clogged (Chapter 1).
Fuel injection system fault (Chapter 4A).
Ignition timing incorrect or ignition system fault (Chapters 1 and 5B).
Brakes binding (Chapter 9).
Tyres under-inflated (Chapter 1).

Fuel leakage and/or fuel odour

Damaged fuel tank, pipes or connections (Chapters 1 and 4A).

Excessive noise or fumes from exhaust system

Leaking exhaust system or manifold joints (Chapters 1 and 4A).
Leaking, corroded or damaged silencers or pipe (Chapters 1 and 4A).
Broken mountings causing body or suspension contact (Chapter 4A).

REF•8

Fault Finding

4 Clutch

Pedal travels to floor - no pressure or very little
resistance

Leak in clutch hydraulic system (Chapter 6).
Faulty hydraulic master or slave cylinder (Chapter 6).
Broken clutch release bearing or fork (Chapter 6).
Broken diaphragm spring in clutch pressure plate (Chapter 6).

Clutch fails to disengage (unable to select gears)

Leak in clutch hydraulic system (Chapter 6).
Faulty hydraulic master or slave cylinder (Chapter 6).

Clutch disc sticking on gearbox input shaft splines (Chapter 6).

Clutch disc sticking to flywheel or pressure plate (Chapter 6).
Faulty pressure plate assembly (Chapter 6).
Clutch release mechanism worn or incorrectly assembled (Chap-

ter 6).

5 Manual transmission

Clutch slips (engine speed increases, with no
increase in vehicle speed)

Clutch disc linings excessively worn (Chapter 6).
Clutch disc linings contaminated with oil or grease (Chapter 6).
Faulty pressure plate or weak diaphragm spring (Chapter 6).

Judder as clutch is engaged

Clutch disc linings contaminated with oil or grease (Chapter 6).
Clutch disc linings excessively worn (Chapter 6).
Faulty or distorted pressure plate or diaphragm spring (Chapter 6).
Worn or loose engine or gearbox mountings (Chapter 2A or 2B).
Clutch disc hub or gearbox input shaft splines worn (Chapter 6).

Noise when depressing or releasing clutch pedal

Worn clutch release bearing (Chapter 6).
Worn or dry clutch pedal bushes (Chapter 6).
Faulty pressure plate assembly (Chapter 6).
Pressure plate diaphragm spring broken (Chapter 6).
Broken clutch disc cushioning springs (Chapter 6).

Difficulty engaging gears

Clutch fault (Chapter 6).
Worn or damaged gear linkage (Chapter 7A).
Incorrectly-adjusted gear linkage (Chapter 7A).
Worn synchroniser units (Chapter 7A).*

Jumps out of gear

Worn or damaged gear linkage (Chapter 7A).
Incorrectly-adjusted gear linkage (Chapter 7A).
Worn synchroniser units (Chapter 7A).*
Worn selector forks (Chapter 7A).*

Vibration

Lack of oil (Chapter 1).
Worn bearings (Chapter 7A).*

Noisy in neutral with engine running

Input shaft bearings worn (noise apparent with clutch pedal

released, but not when depressed) (Chapter 7A).*

Clutch release bearing worn (noise apparent with clutch pedal

depressed, possibly less when released) (Chapter 6).

Noisy in one particular gear

Worn, damaged or chipped gear teeth (Chapter 7A).*

Lubricant leaks

Leaking oil seal (Chapter 7A).
Leaking housing joint (Chapter 7A).*

*Although the corrective action necessary to remedy the symptoms

described is beyond the scope of the home mechanic, the above
information should be helpful in isolating the cause of the condition, so
that the owner can communicate clearly with a professional mechanic.

6 Automatic transmission

Note: Due to the complexity of the automatic transmission, it is difficult
for the home mechanic to properly diagnose and service this unit. For

problems other than the following, the vehicle should be taken to a

dealer service department or automatic transmission specialist.

Fluid leakage

Automatic transmission fluid is usually deep red in colour. Fluid

leaks should not be confused with engine oil, which can easily be
blown onto the transmission by air flow.

To determine the source of a leak, first remove all built-up dirt and

grime from the transmission housing and surrounding areas, using a
degreasing agent or by steam-cleaning. Drive the vehicle at low
speed, so that air flow will not blow the leak far from its source.
Raise and support the vehicle, and determine where the leak is
coming from. The following are common areas of leakage.

a) Fluid pan (transmission "sump").
b) Dipstick tube (Chapter 1).
c) Transmission-to-fluid cooler fluid pipes/unions (Chapter 7B).

Transmission fluid brown, or has burned smell

Transmission fluid level low, or fluid in need of renewal (Chapter 1).

General gear selection problems

The most likely cause of gear selection problems is a faulty or

poorly-adjusted gear selector mechanism. The following are
common problems associated with a faulty selector mechanism.

a) Engine starting in gears other than Park or Neutral.
b) Indicator on gear selector lever pointing to a gear other than the

one actually being used.

c) Vehicle moves when in Park or Neutral.
d) Poor gear shift quality, or erratic gear changes.
Refer any problems to a Saab dealer, or an automatic transmission

specialist.

Transmission will not downshift (kickdown) with

accelerator pedal fully depressed

Low transmission fluid level (Chapter 1).
Incorrect selector cable adjustment (Chapter 7B).

Engine will not start in any gear, or starts in gears
other than Park or Neutral

Incorrect starter inhibitor switch adjustment - where applicable

(Chapter 7B).

Incorrect selector cable adjustment (Chapter 7B).

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