Common MOT Failures Revealed

The annual MOT test is a legal requirement for most vehicles over three years old in the UK, ensuring they meet minimum road safety and environmental standards. While many drivers approach this test with a degree of trepidation, fearing unexpected costs, understanding the common reasons for failure can significantly improve a vehicle's chances of passing. Recent analysis of data from the Driver and Vehicle Standards Agency (DVSA) by the RAC sheds light on the most frequent culprits behind an MOT fail, highlighting areas where drivers should pay particular attention.

The Top Offenders: Lighting, Suspension, and Brakes

It might come as a surprise to some, but the most common reason for a vehicle failing its MOT test is related to lighting. Faulty headlights, indicators, and reflectors collectively account for over a quarter (25.5%) of all MOT failures. This underscores the critical importance of ensuring all lights are functional, correctly aimed, and free from damage. Imagine driving with a malfunctioning brake light or a dim headlight; not only is it a legal offence, but it severely compromises your ability to see and be seen, increasing the risk of an accident.

Following closely behind lighting issues, problems with suspension components are the second most frequent cause of failure, responsible for a substantial 18.3% of all failed tests. Worn or damaged suspension can affect steering, braking, and overall vehicle stability, making it a significant safety concern. Broken shock absorbers, worn bushes, or damaged springs can all lead to an MOT fail.

Brakes, a cornerstone of vehicle safety, are also a major reason for MOT failures, contributing 17% of all test failures. This includes issues with brake pads, discs, fluid levels, and the effectiveness of the braking system itself. Given their vital role in stopping your vehicle, it's no wonder that brake problems are scrutinised so closely.

Tyres: The Weakest Link?

Tyres, the only point of contact your vehicle has with the road, are another significant factor in MOT failures, accounting for 12% of all tests. This figure is concerning, especially as data suggests an upward trend in tyre-related failures, increasing from 10% in 2018-19. The Institute of the Motor Industry even suggests that tyres are becoming the 'weakest link' in vehicle maintenance. This is particularly true for electric vehicles (EVs), which are more likely to fail on tyre issues, making up 46% of all EV test failures. This could be attributed to the instant torque and heavier weight of EVs, leading to increased tyre wear.

What makes tyre failures particularly worrying is their classification. When tyres contribute to a dangerous defect – meaning the vehicle cannot be driven until the problem is rectified – they are a serious concern. In fact, tyres and brakes together make up a staggering 88% of all dangerous defects identified during MOT tests. These dangerous faults, in general, now account for nearly one in ten (8.1%) of all MOT failures, highlighting the critical need for regular tyre checks.

Visibility: Don't Get Caught Out

Poor visibility is another area that can lead to an MOT failure, accounting for 8.7% of all test failures. This encompasses a range of issues, including damaged or obscured windscreens, faulty windscreen wipers and washers, and even the condition of your wing mirrors. A clear view of the road is paramount for safe driving, and any obstruction or malfunction in visibility systems will be flagged during the test.

The Reality of MOT Failures

The statistics paint a clear picture: one in three initial MOT tests for cars and vans results in a failure. This means a significant portion of drivers are faced with the cost of remedial work, often for issues that could have been identified and addressed proactively. As Nicholas Lyes, RAC head of roads policy, points out, many drivers dread the MOT due to the potential for expensive repairs.

However, he also offers valuable advice: "Drivers should never ignore dashboard warning lights as they could end up putting themselves or others at risk and costing themselves a lot of money with a bigger repair bill than necessary had they acted straightaway." Dashboard warning lights are your vehicle's way of communicating a potential problem. Addressing these promptly can often prevent minor issues from escalating into costly failures.

Furthermore, routine servicing plays a crucial role in reducing the likelihood of an MOT failure. Regular servicing typically includes a comprehensive check of many components that are also assessed during the MOT, such as lights, brakes, tyres, and fluid levels. It’s a proactive approach to vehicle maintenance that can save you money and stress in the long run.

Proactive Checks: What You Can Do

Beyond regular servicing, there are several simple checks that vehicle owners can perform themselves to help prevent an MOT failure:

• Lights: If your vehicle doesn't have modern dashboard warning lights for all its external lights, ask a friend or family member to help you check that all headlights, taillights, brake lights, and indicators are working correctly.
• Tyres: Ensure your tyres are inflated to the correct pressure (check your vehicle handbook or the sticker on your door frame) and that they have adequate tread depth. The legal minimum tread depth is 1.6mm across the central three-quarters of the tyre's width. Also, inspect tyres for any cuts, bulges, or signs of uneven wear. A smooth driving style can also help prolong tyre life.
• Brakes: While a full brake check requires professional expertise, you can listen for any unusual noises when braking, such as grinding or squealing. A spongy brake pedal can also indicate a problem.
• Visibility: Ensure your windscreen is free from chips or cracks in your line of sight. Check that your windscreen wipers are in good condition and that the washer fluid reservoir is topped up.
• Dashboard Warnings: As mentioned, never ignore any illuminated warning lights on your dashboard. Consult your vehicle's manual to understand what the light signifies and seek professional advice if necessary.

When Something Doesn't Feel Right

Mr. Lyes also advises, "if something doesn’t sound or feel right, to get checked at a trusted garage as soon as possible." Don't wait for the MOT test to discover a potential issue. If you notice unusual noises, vibrations, or changes in your vehicle's handling, it's always best to have it inspected by a qualified mechanic promptly.

Common MOT Failure Categories Summarised

To provide a clearer overview, here's a summary of the most common MOT failure categories based on the RAC's analysis:

Frequently Asked Questions

What are the most common reasons for a car to fail its MOT?

The most common reasons for an MOT failure are issues with lighting (headlights, indicators, brake lights), suspension components, brakes, tyres, and visibility (windscreen, wipers).

Can I drive my car if it fails its MOT?

You can generally drive your car if it fails its MOT, provided the existing MOT has not expired and the failure is not classified as 'dangerous'. If the failure is 'dangerous', you must not drive the vehicle until it has been repaired.

How can I prevent my car from failing its MOT?

Regular servicing, proactive checks of lights, tyres, brakes, and wipers, and addressing dashboard warning lights promptly can significantly help prevent an MOT failure. Paying attention to any unusual sounds or feelings from your vehicle is also crucial.

Are electric vehicles more likely to fail their MOT?

While not a universal rule, EVs are noted to be more likely to fail on tyre-related issues due to their weight and instant torque, leading to increased tyre wear.

What should I do if my car fails its MOT?

If your car fails its MOT, you will receive a report detailing the reasons for failure. You will need to arrange for the necessary repairs to be carried out and then have the vehicle re-tested. If the existing MOT has not expired and the failure is not dangerous, you can drive the car to a pre-booked MOT test appointment or to a place of repair.

In conclusion, while the MOT test can seem daunting, understanding the common failure points empowers drivers to take a more proactive approach to vehicle maintenance. By regularly checking key components and addressing potential issues before they become serious problems, you can significantly increase your vehicle's chances of passing its MOT, ensuring your safety and avoiding unnecessary expense.