Windmill Garage Horndean

The Most Common Reasons For MOT Failure

The possibility of having your car fail an MOT test is most drivers’ annual nightmare. It’s time consuming, inconvenient and generally a hassle. And that’s before taking into account the cost of getting the vehicle back on the road. Some of the reasons for MOT failure are very common. Understanding why cars fail this important test is the first step in preparing your vehicle to pass.

The MOT or Motor Operations Test is a broad examination that tests the various features of a car. As you’d expect it is regulated by government legislation. The MOT tests most working elements but does not cover the engine, gearbox or clutch in any great detail beyond checking that the car runs without a major error. Instead, it focuses primarily on the areas and functionality that make the car safe for you and other road users.

Modern MOTs also include a number of environmental standards checks, which is why the emissions and fuel systems are tested. The diagram below shows a comprehensive checklist of the areas checked in a typical MOT inspection. Failing to meet the required standards for any of these features will result in an automatic fail.


reasons for MOT failure

Reasons for MOT Failure

Out of all of these items, there are several that are likely to cause your car to fail.

  1. Tyre Tread – Your car must have at least 1.6mm of tread otherwise it is deemed unsafe.
  1. Brake Pads – These need to be at least 1.5mm thick. Anything less is likely to limit braking ability.
  1. Headlamps – There are limits on how high or low these can be aimed in order to avoid impairing other motorists. It goes without saying that all bulbs need to be in good working order.
  1. Weakened Brake Discs – Damage to discs can really impede your ability to stop and could cause accidents.
  1. Windscreen Wipers – If your wipers do not clear the screen or are damaged, expect your car to fail. Wipers are something you can easily replace yourself prior to the test.
  1. Windscreen Damage – Chips or scratches in your screen can lead to serious damage and are not acceptable from a test perspective.
  1. Registration Plate – Displaying a plate is a legal requirement so if it’s unreadable due to wear or fading, or even dirt and rust, it will be deemed illegal.
  1. Registration Lamp – If this doesn’t light up, your number plate cannot be read. If it’s faulty, expect an MOT fail.
  1. Brake Lights – Break lights warn others you are stopping so if they don’t work, the chances of a serious accident are higher.
  1. Windscreen Washers – Being able to clean your screen is a legal requirement. Insufficient washer liquid or impaired functionality is an automatic fail.

These are the most common reasons that vehicles fail an MOT test. The good news is that the majority are items you can check personally before the test to improve your chances of passing first time.

If you have any questions or stories from your past MOT experiences, let us know on our social media pages.

mot testing station, reasons for MOT failure