Via Veloce by Wille R.  Internet since November 1995 and still here.  

Alfa Romeo fault diagnosis. Some common symptoms and perhaps some reasons.

Top Cooling system overheating   

  1. Insufficient coolant in system
  2. Pump ineffective due to slack drivebelt
  3. Radiator blocked either internally or externally
  4. Kinked or collapsed hose causing coolant flow restriction
  5. Thermostat not working properly
  6. Engine out of tune
  7. Ignition timing retarded or auto advance malfunction
  8. Cylinder head gasket blown
  9. Cylinder head gasket blown
  10. Exhaust system partially blocked
  11. Engine oil level too low
  12. Brakes binding

Top  Engine running too cool

  1. Faulty thermostat
  2. Incorrect or missing thermostat

Top Loss of coolant

  1. Loose hose clips
  2. Hoses perished or leaking
  3. Radiator leaking
  4. Radiator leaking
  5. Blown cylinder head gasket
  6. Cracked cylinder block or head
  7. Leaking from heater control

Top  Heater gives insufficient output

  1. Engine overcooled (see above)
  2. Heater matrix blocked
  3. Heater controls maladjusted or broken
  4. Heater control valve jammed or otherwise defective

Top Fuel system - Fuel smell

  1. Smell of petrol when engine is stopped
  2. Leaking fuel lines or unions
  3. Leaking fuel tank
  4. White smoke from exhaust, check the brake fluid. Booster could be leaking
  5. Blue or black smoke from exhaust. Worn piston rings or valve guides let engine oil pass by

Top Smell of petrol when engine is idling

  1. Leaking fuel line unions between pump and carburettor
  2. Overflow of fuel from float chamber due to wrong level setting,
  3. ineffective needle valve or punctured float

Top Excessive fuel consumption for reasons not covered by leaks or float chamber faults

  1. Worn jets
  2. Over-rich setting
  3. Sticking mechanism
  4. Dirty air cleaner element

Top Difficult starting, uneven running, lack of power, cutting out

  1. One or more jets blocked or restricted
  2. Float chamber fuel level too low or needle valve sticking
  3. Float chamber fuel} level too low or needle valve
  4. Fuel pump not delivering

Top Difficult starting when cold

  1. Choke control
  2. Insufficient use of manual choke
  3. Weak mixture

Top Difficult starting when hot

  1. Excessive use of manual choke
  2. Accelerator pedal pumped before starting
  3. Vapour lock especially in hot weather or at high altitude)
  4. Rich mixture

Top  Engine does not respond properly to throttle

  1. Faulty accelerator pump
  2. Blocked jets
  3. Slack in accelerator cable

Top Engine idle sped drops when hot

  1. Incorrect air cleaner intake setting
  2. Overheated fuel pump

Top  Engine runs on

  1. Idle speed too high
  2. Too rich mixture

Top  Ignition system - Mechanical breaker system  Engine fails to start

  1. Loose battery connections
  2. Discharged battery
  3. Oil in contact points
  4. Disconnected ignition leads
  5. Faulty condenser

Top  Engine starts and runs but misfires

  1. Faulty spark plug
  2. Cracked distributor cap
  3. Cracked rotor arm
  4. Worn advance mechanism
  5. Incorrect spark plug gap
  6. Incorrect contact points gap
  7. Faulty condenser
  8. Faulty coil
  9. Incorrect timing
  10. Poor engine / transmission earth connections

Top Engine overheats, lacks power

  1. Seized distributor weights
  2. Perforated vacuum pipe
  3. Incorrect ignition timing

Top  Eectronic type - Engine fails to start

  1. Excessive gap on TDC sensor
  2. TDC or engine speed sensor short circuited or earthed
  3. Defective ignition control unit
  4. Control unit multiplug contacts corroded
  5. Defective coil

Top Engine lacks power, high fuel consumption

  1. Incorrect ignition advance
  2. TDC sensor incorrectly set
  3. Distributor vacuum hose blocked

Top  Clutch - transmission   Difficulty in engaging gear (grinding)

  1. Clutch cable adjustment incorrect
  2. See under Clutch spin
  3. Judder when taking up drive
  4. Engine / transmission mountings loose or worn
  5. Driven plate linings contaminated or worn
  6. Pressure plate loose or defective

Top  Clutch spin (failure to disengage) so that gears cannot be meshed

  1. Incorrect release bearing to pressure plate clearance on splines (may occur after vehicle standing idle for long periods)
  2. Damaged or misalign pressure plate assembly stretched or broken

Top Clutch slip, increase in engine but speed does not increase, road speed

  1. Incorrect cable adjustment
  2. Driven plate linings worn or contaminated
  3. Pressure plate defective

Top  Noise evident when clutch pedal depressed

  1. Release arm pivots unlubricated
  2. Release bearing worn, loose or unlubricated
  3. Worn or damaged pressure plate

Top  Noise evident as clutch pedal released

  1. Distorted driven plate
  2. Broken or weak driven plate cushion coil springs
  3. Incorrect pedal adjustment
  4. Weak or broken clutch pedal return spring
  5. Distorted or worn input shaft
  6. Release bearing loose on retainer hub

Top Weak or ineffective synchromesh

  1. Synchro bulk rings worn, split or damaged
  2. Synchromesh units worn, or damaged

Top  Jumps out of gear

  1. Gearchange mechanism worn
  2. Synchromesh units badly worn
  3. Selector fork badly worn

Top  Excessive noise in transmission

  1. Incorrect grade of oil in gearbox or oil level too low
  2. Gearteeth excessively worn or damaged
  3. Intermediate gear thrust washers worn allowing excessive end play
  4. Worn bearings
  5. Worn universal joint, tickling noise when driving off
  6. Heavy knocking when driving off is often the propeller shaft support bearing
  7. Ticking noise when driving off is often universal joint at rear axle.

Top  Difficulty in engaging gears

  1. Clutch pedal adjustment incorrect
  2. Hydralic fluid level too low

Top  Noise when cornering

  1. Wheel bearing or driveshaft fault
  2. Differential fault

Top  Braking system  Excessive pedal travel

  1. Pads or shoes excessively worn
  2. Incorrect pedal or servo pushrod adjustment
  3. Automatic adjusters faulty
  4. Seized wheel cylinder or calliper piston
  5. Master cylinder seals worn

Top Pedal feels spongy or soggy

  1. Air in hydraulic system
  2. Low fluid level
  3. Loose connections
  4. Flexible hose perished
  5. Defective wheel cylinder or calliper seal

Top  Pedal feels springy

  1. New pads or linings not bedded-in
  2. Master cylinder mounting loose

Top  Excessive effort required to stop car

  1. Worn or contaminated linings or pads
  2. Incorrect grade of lining or pad material
  3. Servo vacum hose leaking or disconnected
  4. Faulty servo or non-return valve
  5. Seized calliper or wheel cylinder piston
  6. I.e. circuit defective on dual circuit hydraulic system

Top  Brakes pull to one side

  1. Friction linings contaminated on one side of car
  2. Seized hydraulic piston on one side of car
  3. Different types of linings fitted on different sides of car, or new linings on one side only
  4. Seized automatic adjuster on one side of car

Top  Pedal vibrates when brakes applied

  1. Discs or drums distorted
  2. Friction linings excessively worn
  3. Loose backplate or calliper mounting bolts

Top  Brakes squeal

  1. Disks rusty or damp, often temporary fault with no action needed.
  2. Dust or grit in brake drums
  3. Linings excessively worn

Top  Loosing Brake fluid

  1. Worn servo/booster seals and gaskets. 
  2. Worn air control valve
  3. Worn seals in brake master cylinder. Shown by leaks from the MC
  4. Leaking from junction


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