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Car Breakdowns

Common Causes of Breakdown

The key to avoiding a breakdown is good and regular maintenance together with an understanding of what's most likely to go wrong.

Many of these faults can be fixed at the roadside, but most can be avoided with the correct preventative care.

Below is the top 10 causes of breakdown.

1) - Flat of Faulty Battery

	Most common problems are caused by terminals and clamp connections or by a loss of voltage, often caused by constant use on short journeys without regular recharging.
	At every service, check that terminals have been cleaned and protected from corrosion with a layer of petroleum jelly or grease. Clamps and connections must be secure.
	If you seldom make a long journey, a fortnightly overnight charge prolongs battery life.
	Modern maintenance-free batteries need no top-up.

2) - Lost Keys

3) - Flat / Damaged Tyres and Wheels

4) - Alternator Faults

5) - Starter Motor

6) - Distributor Cap

7) - Fuel Problems

8) - Clutch Cables

9) - Spark Plugs

10) - HT Leads

Government Policy

	Check the handbook and adjust pressures as required to suit different speeds and loads.
	Kerb impact can damage sidewalls and, possibly wheel rims. Both can result in slow leaks. Consult a specialist tyre dealer if any damage is visible.
	When checking tread depth, look for uneven tyre wear – the wheels may be misaligned.
	Look at the spare tyre. A worn or flat spare won't be of use in an emergency.
	Check that the jack and wheel-removal tools are in good condition and that the key or removal tool for locking wheel nuts is accessible.

	Most modern cars have a 'transponder' key combining a conventional mechanical key with an encrypted electronic chip to prevent theft.
	If you lose the key, recovery to an authorised dealer may be the only answer.
	Even a dealer may take several days to obtain a replacement, so if possible carry or have access to a spare set of keys.

	Persistent battery problems and dim headlights when the engine is idling can indicate alternator/generator faults.
	Belts driving the alternator may also operate the radiator fan and water pump. A red ignition warning light plus a rapid rise in engine temperature could indicate a broken belt. Stop straight away.

	Though usually robust, starter motors can fail.
	Good, regular garage maintenance should highlight potential faults.

	Moisture and dirt are the chief enemies - a crack in the cap's insulation may be almost invisible but can be sufficient to allow high ignition voltage to leak away, especially in damp weather, so there may be no ignition spark.
	Replace the cap at the car manufacturer's recommended intervals.
	Replace weather protection covering the cap if it becomes split.

	Empty fuel tanks cost a lot of time and inconvenience. Fill up at the start of your journey and well before the low-fuel warning light comes on.
	Every year more than 150,000 motorists put the wrong fuel in their car – ensure you pay attention when choosing your fuel

	Clutch cables are under high stress, and abrasion can weaken the wire strands until they break.
	Temporary repairs at the roadside can be available, but replacement at the first signs of wear is the best answer.

	The spark plug is a much-neglected part of the ignition system.
	Make sure that you replace plugs at the manufacturer's recommended service intervals.

	High-tension (HT) leads and their connections can deteriorate with age. Water and dirt enter cracks in the insulation, reducing ignition voltage.
	Damp-repellent sprays are only a temporary solution.
	Ask your garage to check the condition of the leads and replace as necessary.