Via Veloce
by Wille R. www.veloce.se
Internet since November 1995 and still here.
Alfa Romeo fault diagnosis. Some common symptoms and perhaps some
reasons. Thanks to Highwood
Motor Co . There are a lot of clues for DIY at Via veloce. If you have
any comments or suggestions or have an other idea about the content,
please tell us, thank you.
Klick on the link you wish to follow.
Engine fails to turn when starter operated
Starter motor turns engine slowly but fails
to start
Starter motor spins without turning engine
Engine turns normally but fails to start
Engine fires but will not run
Engine cuts out and will not restart
Engine misfires before cutting out - fuel fault
Engine cuts out - other causes
Engine overheats
Low engine oil pressure
Engine noises
Whistling or wheezing noises
Tapping or rattling
Knocking or thumping
Engine fires but will not run
Difficult starting when cold
Difficult starting when hot
Engine slow to warm up
Engine idles roughly
Engine lacks power
Engine misfires throughout speed range
Poor engine braking
Pre-ignition (pinking) during acceleration
Engine Backfires
Engine runs on after switching off
Low oil pressure (verify accuracy of
sender before dismantling)
Excessive oil consumption
Oil contaminated with water
Oil contaminated with fuel
Oil smoke
Unusual mechanical noises
Cooling system overheating
Engine running too cool
Loss of coolant
Heater gives insufficient output
Fu1iel system - Fuel smell
Smel1 of petrol when engine is idling
Excessive fuel consumption for reasons not covered by
leaks or float chamber faults
Difficult starting, uneven running, lack of power,
cutting out
Difficult starting when cold
Difficult starting when hot
Engine does not respond properly to throttle
Engine idle sped drops when hot
Engine runs on
Ignition system - Mechanical breaker system
Engine fails to start
Engine starts and runs but misfires
Engine overheats, lacks power
Electronic type - Engine fails to start
Clutch
- transmission
Difficulty in engaging gear (grinding)
Clutch spin (failure to disengage) so that gears
cannot be meshed
Clutch slip, increase in engine but speed does
not increase, road speed
Noise evident when clutch pedal depressed
Noise evident as clutch pedal released
Weak or ineffective synchromesh
Jumps out of gear
Excessive noise in transmission
Difficulty in engaging gears
Noise when cornering
Braking system
Excessive pedal travel
Pedal feels spongy or soggy
Pedal feels springy
Excessive effort required to stop car
Brakes pull to one side
Pedal vibrates when brakes applied
Brakes squeal
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Cooling system overheating
Insufficient coolant in system
Pump ineffective due to slack drivebelt
Radiator blocked either internally or externally
Kinked or collapsed hose causing coolant flow restriction
Thermostat not working properly
Engine out of tune
Ignition timing retarded or auto advance malfunction
Cylinder head gasket blown
Cylinder head gasket blown
Exhaust system partially blocked
Engine oil level too low
Brakes binding
Top
Engine running too cool
Faulty thermostat
Incorrect or missing thermostat
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Loss of coolant
Loose hose clips
loses perished or leaking
Radiator leaking
Radiator leaking
Blown cylinder head gasket
Cracked cylinder block or head
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Heater gives insufficient output
Engine overcooled (see above)
Heater matrix blocked
Heater controls maladjusted or broken
Heater control valve jammed or otherwise defective
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Fuel system - Fuel smell
Smell of petrol when engine is stopped
Leaking fuel lines or unions
Leaking fuel tank
Top
Smell of petrol when engine is idling
Leaking fuel line unions between pump and carburettor
Overflow of fuel from float chamber due to wrong level
setting,
ineffective needle valve or punctured float
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Excessive fuel consumption for reasons not covered by
leaks or float chamber faults
Worn jets
Over-rich setting
Sticking mechanism
Dirty air cleaner element
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Difficult starting, uneven running, lack of power,
cutting out
One or more jets blocked or restricted
Float chamber fuel level too low or needle valve sticking
Float chamber fuel} level too low or needle valve
Fuel pump not delivering
Top
Difficult starting when cold
Choke control
Insufficient use of manual choke
Weak mixture
Top
Difficult starting when hot
Excessive use of manual choke
Accelerator pedal pumped before starting
Vapour lock especially in hot weather or at high altitude)
Rich mixture
Top
Engine does not respond properly to throttle
Faulty accelerator pump
Blocked jets
Slack in accelerator cable
Top
Engine idle sped drops when hot
Incorrect air cleaner intake setting
Overheated fuel pump
Top
Engine runs on
Idle speed too high
Too rich mixture
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Ignition system - Mechanical breaker system
Engine fails to start
Loose battery connections
Discharged battery
Oil in contact points
Disconnected ignition leads
Faulty condenser
Top
Engine starts and runs but misfires
Faulty spark plug
Cracked distributor cap
Cracked rotor arm
Worn advance mechanism
Incorrect spark plug gap
Incorrect contact points gap
Faulty condenser
Faulty coil
Incorrect timing
Poor engine / transmission earth connections
Top
Engine overheats, lacks power
Seized distributor weights
Perforated vacuum pipe
Incorrect ignition timing
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Eectronic type - Engine fails to start
Excessive gap on TDC sensor
TDC or engine speed sensor short circuited or earthed
Defective ignition control unit
Control unit multiplug contacts corroded
Defective coil
Top
Engine lacks power, high fuel consumption
Incorrect ignition advance
TDC sensor incorrectly set
Distributor vacuum hose blocked
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Clutch - transmission Difficulty
in engaging gear (grinding)
Clutch cable adjustment incorrect
See under Clutch spin
Judder when taking up drive
Engine / transmission mountings loose or worn
Driven plate linings contaminated or worn
Pressure plate loose or defective
Top
Clutch spin (failure to disengage) so that gears cannot
be meshed
Incorrect release bearing to pressure plate clearance on
splines (may occur after vehicle standing idle for long
periods)
Damaged or misalign pressure plate assembly stretched or broken
Top
Clutch slip, increase in engine but speed does
not increase, road speed
Incorrect cable adjustment
Driven plate linings worn or contaminated
Pressure plate defective
Top
Noise evident when clutch pedal depressed
Release arm pivots unlubricated
Release bearing worn, loose or unlubricated
Worn or damaged pressure plate
Top
Noise evident as clutch pedal released
Distorted driven plate
Broken or weak driven plate cushion coil springs
Incorrect pedal adjustment
Weak or broken clutch pedal return spring
Distorted or worn input shaft
Release bearing loose on retainer hub
Top
Weak or ineffective synchromesh
Synchro bulk rings worn, split or damaged
Synchromesh units worn, or damaged
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Jumps out of gear
Gearchange mechanism worn
Synchromesh units badly worn
Selector fork badly worn
Top
Excessive noise in transmission
Incorrect grade of oil in gearbox or oil level too low
Gearteeth excessively worn or damaged
Intermediate gear thrust washers worn allowing excessive end
play
Worn bearings
Worn universal joint, tickling noise when driving off
Heavy knocking when driving off is often the propeller shaft
support bearing
Ticking noise when driving off is often universal joint at rear
axle.
Top
Difficulty in engaging gears
Clutch pedal adjustment incorrect
Hydralic fluid level too low
Top
Noise when cornering
Wheel bearing or driveshaft fault
Differential fault
Top
Braking system Excessive pedal travel
Pads or shoes excessively worn
Incorrect pedal or servo pushrod adjustment
Automatic adjusters faulty
Seized wheel cylinder or calliper piston
Master cylinder seals worn
Top
Pedal feels spongy or soggy
Air in hydraulic system
Low fluid level
Loose connections
Flexible hose perished
Defective wheel cylinder or calliper seal
Top
Pedal feels springy
New pads or linings not bedded-in
Master cylinder mounting loose
Top
Excessive effort required to stop car
Worn or contaminated linings or pads
Incorrect grade of lining or pad material
Servo vacum hose leaking or disconnected
Faulty servo or non-return valve
Seized calliper or wheel cylinder piston
I.e. circuit defective on dual circuit hydraulic system
Top
Brakes pull to one side
Friction linings contaminated on one side of car
Seized hydraulic piston on one side of car
Different types of linings fitted on different sides of car,
or new linings on one side only
Seized automatic adjuster on one side of car
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Pedal vibrates when brakes applied
Discs or drums distorted
Friction linings excessively worn
Loose backplate or calliper mounting bolts
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Brakes squeal
Disks rusty or damp, often temporary fault with no action needed.
Dust or grit in brake drums
Linings excessively worn
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