What can fail an MOT: Common problems and what you can do about them

In May 2018, the government changed the way the MOT test worked, including a different categorisation of defects. Two of these result in a failed MOT:

• Dangerous
• Major

There are three other categories, all of which result in a pass:

• Minor defects – to be repaired as soon as possible
• Advisory – keep an eye on the situation and book in for repairs if required
• Pass – ensure the car continues to meet the legal standard

One year on from the changes to the test, a study using data from the Driver and Vehicle Standards Agency (DVSA) found that more than 10 million cars had failed the new MOT – a significant rise when compared to figures from the preceding 12 months (7.3 million).

Any dangerous or major defects mean your car poses a risk to road safety or has the potential to have an impact on the environment. In either of these cases, you should not drive the vehicle and the repairs should be carried out immediately, otherwise your car will not be deemed legally roadworthy.

No. To do so would be to put yourself and other road users at risk. If you are found to be driving a car with a major or dangerous fault, you could be fined up to £2,500, so you must get those defects fixed before you get back behind the wheel.

There are a number of reasons why your car might fail its MOT. Here, we run through some of the more familiar parts of a vehicle and whether or not they have the potential to cause you a problem when it comes to the time of your test.

Will a cracked windscreen fail an MOT?

Yes, a cracked windscreen has the potential to cause a failed MOT. The maximum size of damage for any cracks in the driver’s line of vision is 10mm. For anywhere else, the maximum is 40mm. Even the tiniest of chips can ultimately lead to your windscreen shattering, so it makes sense to get any cracks repaired before you head for your MOT.

Can you fail an MOT on windscreen wipers?

Yes. If your wipers are broken, missing or not working effectively, it could hamper your ability to see clearly out of your windscreen. In that instance, your car is likely to receive a major fault and fail its MOT.

Does an oil leak fail an MOT?

Depending on the severity of the issue, an oil leak could mean a failed MOT. A small leak is likely to only receive a minor fault, which would come with a recommendation to get the problem seen to as soon as possible. However, a more serious leak could result in a major defect and a fail.

Will a cracked light fail an MOT?

According to the DVSA, lights are the most common reasons for MOT failures. Blown bulbs – whether that be for headlights, brake lights, fog lights or reversing lights – could all be classed as a major fault, so make sure you check them beforehand and replace any that are broken. Cracked coverings could also affect the pattern of light shining through, so it’s best to get these seen to prior to your test.

Can you fail an MOT on tyres?

Yes. Your tyres’ tread depth must measure a minimum of 1.6mm to pass your MOT. However, it’s advised that you replace them once the depth reaches 3mm, as a tyre’s braking capabilities decline significantly beyond that point.

Can a car fail an MOT on its airbag light?

Yes. If your airbag light is on, your vehicle will fail its MOT. If the light is on but the airbags haven’t deployed, this could be a sign of an electrical fault. Alternatively, it may be on due to a minor accident and will simply need resetting. Both of these issues would need to be looked at by a trained mechanic.

Will a loud exhaust fail an MOT?

If your exhaust emits a noise deemed to be “unreasonably above the level you’d expect from a similar vehicle with a standard silencer in average condition”, then it could receive a major defect and would therefore fail its MOT.

Will a car fail its MOT with the ABS light on?

The anti-lock braking system is there for your safety – it brings your vehicle to a more controlled stop when under sudden braking. ABS has been a legal requirement for a number of years, and if your light is showing up on the dashboard then your car will fail its MOT and you’ll be required to fix the problem before you can drive again.

Will a broken wing mirror fail an MOT?

If the wing mirror on the driver’s side is missing, excessively damaged or insecure, your car will be given a major defect and fail its MOT. If the wing mirror on the passenger side is missing or damaged, that will not result in a fail. However, it could make manoeuvres or lane changing extremely hazardous, so it is recommended to have the issue fixed as soon as possible.

Will a damaged bumper fail an MOT?

That depends on the extent of the damage. For example, if your bumper is only lightly scratched or dented, it’s unlikely your car will fail its MOT. But if it is detached, that will be classed as a dangerous defect and if it is insecure or has suffered damage which could cause injury when contacted, that will go down as a major fault.

Do warning lights fail an MOT?

Yes, the illumination of any warning light will result in a failure of your MOT. If anything on your dashboard lights up, you should get the issue looked at as soon as possible, as it could signify a serious problem with your vehicle.

To avoid failing your MOT, it’s important to take good care of your car and ensure everything is running as efficiently as possible. When it comes to testing time, you want to be confident that your vehicle is in the safe hands of fully qualified professionals, so why not book your MOT with Jardine.

We have 60+ dealerships located nationwide and our technicians can offer comprehensive services and vehicle health checks to provide you with that all-important peace of mind.

From body repairs and tyre fitting to spare parts and air conditioning maintenance, we’ve got every aspect of your car covered so you don’t need to worry. To find out more, or if you have any questions, please feel free to get in touch and we’ll be happy to help.

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