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Top ten causes of breakdown - and how to cure them

1.  Car difficult or impossible to start, especially in damp weather.  Engine turns over at normal speed.  Or else car may start, but misfire badly especially when cold.

Cure:  Remove the ignition leads one at a time.  Clean them in petrol, wipe dry with paper towels and refit.  Clean the outside of the distributor cap and top of ignition coil in the same way.  Next, remove the distributor cap and carefully clean the inside using paper towels.  Do the same to the rotor arm.  If your car has old fashioned points ignition, check that the contacts are not excessively pitted - if so, clean them up carefully with a small file, ensuring that both faces remain flat.  Check the points gap with a feeler gauge - a setting of 0.35 - 0.40mm will work with pretty much any car.  Remove each spark plug in turn and clean it up with a wire brush.  Reset the electrode gap to 0.70mm - again, this setting should work for pretty much any vehicle.  Finally, spray the plug leads, coil and distributor cap with a coating of WD40. 

Note that if the plugs or points are very worn, you will probably have to replace them to cure the problem.  They are not usually expensive.

2.  Battery gradually goes flat over a period of several days, especially when using lights, wipers etc. Can be fully recharged using a battery charger.

Cure:  Most likely cause is a loose fanbelt.  In this case you will usually notice a loud squealing noise, especially when you turn the lights on.  Either tighten the fanbelt, or if it is very worn, replace it.  If fanbelt is OK, the alternator is probably faulty and needs replacing.  An auto-electrician will be able to test and confirm this very quickly.  Alternator faults are extremely common in old cars, and do not always cause the charge warning light to illuminate.

3.  Car is difficult to start from cold.  Engine turns over very slowly.  Car will start immediately if jump-started, and will start OK when engine is warm.

Cure:  The chances are that the lead plates in the battery have become coated with hard lead sulphate, reducing the performance of the battery.  But first check that the battery connections are clean and tightly secured.  If they are covered with corrosion, clean them up and then smear them with Vaseline to prevent future corrosion.  Also check that the fluid level in the battery is correct - if it is low, top up with distilled water.  If this produces no improvement you may need a new battery, but it is worth trying a chemical treatment called EDTA+, which removes the hard sulphate coating and restores the battery to full efficiency.  Visit Pure Research's website at to find out more about this treatment.

4.  Battery is completely dead.  Car can be jumpstarted, but battery refuses to hold any charge at all, even when charged overnight with a battery charger.  Fluid level in one or more cells of battery is very low.

Cure:  The battery has an internal fault.  Sorry, but there is no alternative to buying a replacement.

5.  Car overheats, but only when in stationary or slow-moving traffic.

Cure:  Most cars produced in the last 20 years have electric cooling fans, automatically controlled by a temperature sensing switch.  Either the fan or the switch can fail.  Locate the switch (usually on the side of the radiator), pull the wiring plug from it.  Switch on the ignition, and bridge the two terminals in the plug with a piece of thick wire.  If the fan comes on, the switch is faulty.  If it does not, check that the fuse has not blown (refer to handbook or Haynes manual to find out which fuse to check).  If the fuse is OK, try connecting the fan directly to a car battery using a couple of pieces of heavy gauge wire.  If the fan now works, the fault is in the wiring somewhere, and you may need an auto electrician to trace it.  If the fan does not work even when connected directly to a power source, it is dead and should be replaced.

If you are stuck in traffic and the temperature gauge starts to climb towards the red, turn the heater on full blast.  This will take excess heat from the engine and dump it inside the car, and will probably be just enough to keep the needle out of the red zone until you can get moving again.  Once on the move, there is enough airflow to keep the engine cool without the cooling fan being needed.

6.  While driving along, especially in cold, damp weather, engine gradually loses power until it barely runs at all.  On pulling off the road, the engine stops and will not restart.  If left for a couple of minutes it will start and run perfectly.  The symptom may recur several times during a journey.

Cure:  This is almost certainly caused by carburettor icing.  Next time it happens, if you have a car where the top of the airfilter can be quickly removed, unclip it and look inside the carburettor.  You should see a large build-up of ice.  Once the engine has stopped, the ice quickly melts.  Almost all cars have a system which takes hot air from around the exhaust manifold and feeds it into the air intake in cold weather.  The hot air feeds through a flexible tube (basically cardboard covered in silver foil) which disintegrates over time, until it falls off altogether.  If you are having carburettor icing problems, almost certainly it is because this tube is damaged or missing.  If the tube is in place, the problem is probably with the mechanism that controls the flow of hot air according to air temperature.  Check the pipework to this mechanism (which is mounted somewhere on the air filter housing).  If the pipework is OK, the vacuum operated flap which regulates the air filter is faulty.  Replace the complete air filter housing with one from a scrap car.

7.  As you are driving along there is a loud bang from the engine, followed by a rattling sound and total loss of power.  On lifting the bonnet everything appears OK - plenty of oil in the engine and no obvious faults.

Cure:  Your cambelt has broken, and it is entirely your fault for not replacing it as soon as you bought the car.  This is going to be expensive - the cylinder head will have to come off for inspection.  At the very least several valves will need replacing, and if there is damage to any of the pistons, you are looking at a full engine rebuild or a good second hand replacement engine - or scrapping the car.  A cambelt costs £10, and most garages will supply and fit it for under £100 all in.  This is one piece of preventative maintenance that is well worth doing even on the cheapest of cars.

8.  A loud grating sound whenever the brakes are applied.  Car may also pull to one side under braking.

Cure:  The front brake pads have worn down to the backing metal, which is now digging in to the brake discs and will have already scored them so badly that they will have to be replaced. Check brake pads at each service, and replace them when the material thickness gets below around 5mm.  Note that scored brake discs will very quickly destroy a new set of pads.  Discs are surprisingly cheap for most cars.  Modern asbestos-free brake pads are much harder than the older type, and it is not uncommon for brake discs to only last the life of one set of pads.

9.  You depress the clutch pedal and it goes straight to the floor with no resistance.  You cannot engage any gears.

Cure:  Almost certainly the clutch cable has broken.  Normally before the cable breaks, the clutch will have become increasingly heavy to operate, but if you drive the car every day you may not have noticed this, as it happens slowly over a period of time.  The fix is a new clutch cable, but if you are stuck blocking a road junction this will not help you much.  So this is what you do:

Switch off the engine and engage first gear.  Once the road in front of you is clear, operate the starter and depress the accelerator about half way.  The engine will start and you will immediately be moving, albeit in first gear.  You can actually change gear without using the clutch - the trick is to knock the gear lever into neutral, then use the accelerator to match the engine speed to what it would be in the next gear up or down for that road speed.  It takes a bit of practice, but when you get the engine speed right the gear will engage with no problems.  If you have to stop, knock the gear lever into neutral and coast to a halt.  To get moving again, repeat the above process.  You need to anticipate road conditions ahead, and avoid coming to a halt if at all possible - too many standing starts in a short time will leave you stranded with a flat battery.

I once managed to drive a Ford Escort fifty miles home after a clutch cable failure - I wasn't an AA member at the time, so knowing this technique saved me a lot of money.  Next time you are on a long journey, practice a few clutchless gearchanges - you never know when you might need them.

10.  While driving along a dull clonking sound suddenly develops.  It sounds as though it is coming from the wheels or suspension.

Cure:  Stop immediately and check that all your wheelnuts are tight.  I once had a wheel come off and it was a fairly alarming experience.  Fortunately the car in question was an old Mini on ten inch wheels, so it didn't have far to fall....  Whenever you have been doing any work on a car which involves removing the wheels, always double-check that the wheelnuts are done up tight before refitting the wheel trims.  If you have a wheel come off, all the wheelnuts will usually have disappeared, and the holes in the wheel will be mangled.  You can often get home by fitting the spare wheel and robbing one nut from each of the other wheels, provided the brake disc/drum and lower suspension components aren't seriously damaged.  But I wouldn't advise this on a Citroen AX which only has three nuts per wheel to start with.


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