Common MOT Failures
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Common MOT Failures

It is UK law that every car over three years old requires an annual MOT test and an MOT certificate to legally be eligible to drive on UK roads. Not having a valid MOT certificate could result in fines, points being added to your license and even a driving ban.

While approximately 70% of all cars pass their MOTs, many which fail, do so due to common issues which can often be prevented.

We have taken data from the Driver and Vehicle Standards Authority (DVSA) to reveal the most common MOT failures and have provided our own advice on how you can avoid these issues with some simple checks.

What Assessments are Carried Out During an MOT?

An MOT test is designed to ensure that your vehicle adheres to road safety and environmental standards.

Note that while an MOT will comprehensively cover all areas of your vehicle to ensure it is safe to drive, it is not to be confused with a vehicle health check or servicing, which identifies and fixes any issues with your car.

It is highly recommended that you have a full service before your MOT to ensure that anything which could cause you to fail your MOT is fixed.

The components checked during an MOT are as follows

  • Lamps, reflectors and electrical equipment including horn, battery and electrical wiring
  • Steering and suspension including shock absorbers, corrosion and fractures
  • Brakes
  • Tyres and road wheels
  • Seat belts
  • Body structure
  • Exhaust, fuel and emissions
  • Drivers view of the road

What are the Most Common MOT Failures?

When it comes to an MOT, the goal is to ensure that your vehicle is safe and so current requirements are therefore relatively strict, however, many vehicles fail their MOT due to simple issues which can easily be prevented.


30% of all MOT faults relate to lighting and signalling.

Blown bulbs are the single biggest cause of MOT failures and yet are one of the simplest issues to fix.

In order to meet requirements, all of your vehicle’s lights including fog, indicator and rear reflectors, must:

  • Be positioned correctly and securely
  • Be in good condition
  • Not be obscured
  • Illuminate with a single operation of the switch
  • Be the correct colour
  • Not be adversely affected by the operation of any other light

Pairs of lights must emit light of the same colour, size and shape.

Headlight aim (both dip beam and main beam) should be aligned below the horizontal, so as not to dazzle other drivers.


13% of all MOT failures are due to issues with suspension.

Springs, shock absorbers and suspension arms and joints will each be inspected during an MOT. Both the front and rear suspension are assessed by looking for the following:

  • No split pins or nuts missing
  • No components excessively damaged or broken
  • All suspension joints and road springs are in good condition
  • Shock absorbers must not leak and must be secure


10% of all MOT faults are related to tyres.

Your tyres must have a tread depth of at least 1.6mm and must be of an appropriate speed and load rating for your vehicle. Key issues involving tyres include:

  • Damage
  • Distortion
  • Cracks
  • Distorted bead rim
  • Insecure attachment to the vehicle
  • Missing wheel nuts or studs


9.6% of all MOT failures are due to brake issues.

Unsurprisingly, the MOT inspection of your vehicle’s brakes is a complex procedure and includes a number of different checks to ensure the vehicle is safe. The key considerations are as follows:

  • Your brakes, pedals and levers should be in good condition
  • Relevant warning lights must work
  • A brake performance test will be carried out to check brake efficiency

Driver’s View of the Road

6.6% of all MOT failures are due to issues with the driver’s view of the road.

An MOT test includes all items affecting the driver’s view of the road, and includes the condition of the windscreen, wipers and washers.

Mirrors and wipers

  •  Rearview mirrors and wing mirrors must be secure and provide adequate views to the rear and side.
  • Wipers and washers must sweep a wide enough area to give the driver an adequate view of the road.


  •  In the area of the windscreen directly in front of the driver, there must not be any damage or obstruction to the view larger than 10mm in diameter.
  • In the remaining areas, there must not be any damage or other obstruction larger than 40mm in diameter.
  • Tinting of windows which significantly affects the driver’s view will cause failure.

What Can You do to Minimise the Risk of MOT Failure?  

Nearly half of all faults found during MOT checks could be avoided by carrying out simple maintenance checks, so it’s worthwhile assessing components such as lights, wipers and tyres before your vehicle is due for an MOT, so as to minimise the risk of failure.

Here are some basic checks you can do for those issues which most commonly result in MOT failure:


Operate all lights from the driver’s seat and have a family member or friend walk around your vehicle to check all lights are working as they should be.


Faults with suspension can be hidden fairly well but there are some checks you can do which should highlight if there is a problem.

  • Are there any unusual “clunks” when driving, particularly when driving over bumpy roads or speed bumps?
  • Observe your car from the outside. Does it appear to sit level, or does it seem to be too high or too low on any one side or corner?
  • Push on each corner of the vehicle. Does it return to its normal level when you release the pressure without bouncing up and down first?


Use a tyre depth gauge to check the tread depth. If you do not have one of these, you can check out our blog on car safety checks you can do from home to find out how you can easily check your tyre depth from the comfort of your own home.

Should your tyres show any signs of damage, here at our Autocare centre in Chepstow, we offer a tyre repair and replacement service which will ensure your tyres are fit for their next MOT.


  • When driving, make a note of if your vehicle pulls to one side as you brake. This could suggest there is an issue.
  • Make sure to check the efficacy of the handbrake by parking your car on a hill and checking to see whether the handbrake holds it securely.

Driver’s View of the Road  

  • Check for obvious cracks in your mirrors which might obscure your view and replace any damaged mirrors.
  • Ensure your wiper blades are in good condition and do not show any signs of damage.
  • Ensure your screenwash is topped up and there is no significant damage to your windscreen.
  • Ensure the screenwash feed is not blocked.

Is Your MOT Due?  

Should you need vehicle servicing, or any repair work carried out before your scheduled MOT, get in touch today and let our expert team take care of it for you.

Likewise, if you’re looking to renew your MOT, our team of highly qualified testers will ensure that your vehicle meets the requirements of all road safety and environmental standards. To book your MOT, call us on 01291 627137.


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