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The top ten car warranty claims

  • Survey reveals the most common mechanical failures
  • Average repair cost of £265 - £166 more than a warranty
  • A used car warranty can protect against expensive fixes

Written by Parkers Published: 19 April 2011 Updated: 1 February 2017

More and more people are looking at buying car warranties in order to save themselves from big bills - and it's easy to see why.

The latest data from Autoprotect, a leading aftermarket warranty provider working in partnership with Parkers, showed that the top ten most common failures each cost more than the price of a years' warranty to repair - meaning owners could be saving money with a simple used car warranty.

The reliability survey, which was carried out between 2008 and 2010, covered cars that were outside of their original warranty period. More than 155,562 claims were recorded during this time and the results were sorted by the number of faults per category.

The top ten used car warranty failure claims were:

1. Sensors - 8,681 claims.

What does this mean?

A modern car depends on a variety of sensors in order to work properly. If one fails then you'll usually either find yourself confronted with a warning light, or broken down.

What's the average cost of the repair?

£125.46. That's £26.64 more than a years' warranty.

2. Alternators - 8,061 claims.

What does this mean?

The alternator is responsible for charging the battery and supplying power to run electrical systems. Without a working alternator the battery will go flat and your car will grind to a halt.

What's the average cost of the repair?

£239.30. That's £149.30 more than a years' warranty.

3. Electric window motors - 7,633 claims.

What does this mean?

Electric window motors and their associated components are complicated assemblies and easily damaged - especially in winter when the glass can stick, causing damage to the motor and gears.

What's the average cost of the repair?

£203.41. That's £104.41 more than a years' warranty.

4. Central locking systems - 7,061 claims.

What does this mean?

Faults with central locking systems can cause difficulties locking or unlocking your car - it may not work at all, at random, or only on a few doors.

What's the average cost of the repair?

£144.21. That's £45.21 more than a years' warranty.

5. Cylinder head gaskets - 6,991 claims.

What does this mean?

The cylinder head gasket seals the two main parts of the engine together. When it fails the engine will usually overheat, run very poorly and burn coolant, causing the exhaust to smoke heavily.

What's the average cost of the repair?

£373.32. That's £274.32 more than a years' warranty.

6. Switches - 6,429 claims.

What does this mean?

Switches account for the majority of controls that you'll use in your car - like those for the headlights. They might just break, stopping a certain function, or jam on, causing mild annoyance when you find your wipers won't turn off.

What's the average cost of the repair?

£111.79. That's £12.79 more than a years' warranty.

7. Starter motors - 5,973 claims.

What does this mean?

The starter motor spins the engine, allowing it to start. Sometimes it'll become intermittent or tired, making the engine hard to start, or it will just stop altogether - leaving you stranded unless you find a helping hand to bump-start your car.

What's the average cost of the repair?

£193.52. That's £94.52 more than a years' warranty.

8. Ignition coils - 5,734 claims.

What does this mean?

The ignition coil is responsible for generating the spark that gets delivered to the spark plugs. If it breaks then the engine will not run, or it may run very poorly. Some engines have more than one coil, multiplying costs.

What's the average cost of the repair?

£102.19. That's £3.19 more than a years' warranty.

9. Water pumps - 4,313 claims.

What does this mean?

The water pump is responsible for circulating coolant around the engine to keep it cool. When it fails it can leak or cause overheating, which can result in a blown cylinder head gasket.

What's the average cost of the repair?

£187.61. That's £88.61 more than a years' warranty.

10. Coil springs - 4,060 claims.

What does this mean?

The coil spring is an integral part of a cars suspension. Springs can corrode over time, or have manufacturing flaws, that cause them to snap - which can be dangerous and severely effect the cars handling.

What's the average cost of the repair?

£111.10. That's £12.10 more than a years' warranty.

Parkers Top Tip

If you're concerned about the long-term reliability of a new car, then see which manufacturer offers the best warranty in our summary here. Don't forget that you can always buy a second-hand car warranty to protect your car and give you peace of mind as well, if it doesn't already have an existing warranty.