What Does an MOT Fail List Entail?
An MOT fail list refers to the common reasons a vehicle might not pass its annual Ministry of Transport (MOT) test. These failures are categorised by the testers into dangerous, major, or minor defects, with dangerous and major faults resulting in an immediate failure. Understanding these potential issues is key to preparing your vehicle and avoiding the stress and cost of a failed test.
- Most MOT failures stem from easily identifiable faults.
- Regular checks can prevent common reasons for failure.
- Understanding the categories of defects is vital.
- A failed MOT means repairs are required before retesting.
- MOT exemption rules apply to very old vehicles.
The MOT test is a legal requirement for most vehicles over three years old, designed to ensure they meet road safety and environmental standards. While the specific criteria are detailed in the MOT Testing Manual, the outcomes often boil down to a predictable set of common problems. These aren't necessarily complex or expensive issues, but rather fundamental aspects of a vehicle's condition that impact its safety or emissions. By familiarising yourself with the most frequent MOT fail points, you can proactively address potential problems before your vehicle is even presented for its test.
The MOT test itself is not a measure of a vehicle's mechanical condition or a check of the engine's performance. Instead, it focuses on a specific set of safety-critical items. Think of it as a comprehensive safety inspection rather than a full service. The examination covers areas such as lights, steering, suspension, brakes, tyres, seatbelts, and emissions. Any component that poses a risk to the driver, passengers, or other road users, or that fails to meet environmental standards, will be flagged. Knowing the common culprits behind MOT failures can save you time, money, and the inconvenience of having to book a retest.
When a vehicle fails its MOT, it receives a refusal certificate outlining the reasons why. To legally drive the vehicle again, these faults must be repaired. Depending on the severity of the faults, the vehicle may or may not be legally allowed to be driven away from the test centre. If the test result is a dangerous fault, the vehicle must not be driven until the repairs are completed. For major faults, it's also highly recommended not to drive the vehicle until fixed. Minor defects are recorded on the certificate but do not cause a failure, though they will need addressing to avoid future issues.
It's worth noting that certain vehicles are exempt from the MOT test, primarily those manufactured before a specific date, often referred to as classic or vintage cars. For instance, in the UK, vehicles manufactured before 1st January 1961 are exempt. This exemption, however, is about age and not necessarily condition; these older vehicles must still be kept in a roadworthy condition. For all other vehicles requiring an MOT, understanding the common fail points is your first line of defence against an unexpected failure.
The Most Common MOT Fail Categories and Checks
The MOT test examines numerous components, but certain areas consistently appear on MOT fail lists. These are usually related to visible wear and tear, or critical safety systems that are relatively straightforward to inspect. Familiarising yourself with these specific checks can help you identify potential issues before they become MOT failures.
Tyres: The Road's First Line of Defence
Tyres are a critical safety component and a frequent cause of MOT failure. The primary concern is tread depth; for most cars, it must be at least 1.6 millimetres across the central three-quarters of the breadth of the tyre. Irregular wear patterns, cuts, bulges, or exposed cord are also immediate reasons for failure. The MOT test also checks that the tyres fitted are the correct size and type for the vehicle and that they match on the same axle.
Lights: Visibility and Signalling
All lights must be present, function correctly, and be the correct colour. This includes headlights (main and dipped beam), taillights, brake lights, indicators, and fog lights. A burnt-out bulb, a cracked lens, or incorrect alignment of headlights can all lead to an MOT failure. The operation of brake lights, ensuring they illuminate when the pedal is pressed, is also rigorously checked. Indicators must flash at the correct rate and be clearly visible.
Brakes: Ensuring Stopping Power
The braking system is paramount for safety. The MOT test checks the condition of brake pipes and hoses for corrosion, leaks, or damage. Brake fluid levels are checked, and the efficiency of the braking system itself is measured using roller brake testers. Any signs of excessive wear on brake pads or discs, a spongy brake pedal, or a handbrake that doesn't hold the vehicle effectively on a gradient will result in a fail. The system must be balanced and effective.
Suspension and Steering: Control and Stability
Components like shock absorbers, springs, suspension arms, and bushes are inspected for excessive wear, damage, or corrosion. A worn suspension bush can lead to poor handling and is a common MOT failure. Similarly, the steering system is checked for play in the steering wheel, worn steering rack components, or damaged gaiters. Any looseness or excessive wear that affects control will cause the vehicle to fail.
Bodywork and Chassis: Structural Integrity
The MOT test includes a check of the vehicle's structure. This involves inspecting the chassis, body panels, and suspension mounting points for severe corrosion or damage that could compromise the vehicle's integrity. While minor surface rust is usually acceptable, significant corrosion that affects structural strength, or sharp edges protruding from the bodywork, will lead to a fail. The MOT Testing Manual defines specific areas that must be free from excessive corrosion.
Windscreen and Wipers: Driver Visibility
The condition of the windscreen is checked for damage. A significant chip or crack in the driver's direct line of sight (within Zone A, approximately the area swept by the driver's wiper) will cause an MOT failure. The windscreen wipers must also effectively clear the windscreen, and the windscreen washer system must be functional, providing fluid to clean the screen. If the wipers leave streaks or the washer jets are blocked, it could be a fail.
The condition of your tyres is one of the most frequently failed MOT elements.
Common Reasons for an MOT Test Failure (The 'Dodgy MOT' List)
When a vehicle fails its MOT, it's often due to one or more issues from a predictable list of common faults. These aren't obscure problems; they are typically straightforward defects that indicate wear, neglect, or poor maintenance. Understanding these frequent offenders can help you perform your own pre-MOT checks.
Lighting Issues
Beyond just bulbs, this includes faulty light switches, damaged wiring that causes lights to short circuit, or incorrectly fitted aftermarket lights that don't meet UK regulations. Ensure all factory-fitted lights are functioning, and any auxiliary lights are installed and wired correctly. Headlights must also be correctly aimed; misaligned headlights are a common failure point, affecting visibility for you and other road users.
Brake System Problems
Corroded brake pipes are a major concern due to their critical safety function. Even minor corrosion on essential brake lines can lead to failure. Also, if brake pads are worn below their minimum thickness or if the brake discs are scored or warped, they will fail the test. A seized brake caliper or a faulty ABS warning light that doesn't illuminate on the dashboard self-test can also cause failure.
Suspension Wear
Worn or damaged suspension components are a frequent cause of failure. This includes bushes that have perished or split, meaning the suspension is no longer held securely. Ball joints that are excessively loose, or damaged anti-roll bar links, are also common fails. The MOT test assesses if these parts have detrimental play that affects steering or stability.
Exhaust Emissions
While modern cars are generally good, older vehicles or those with poorly maintained engines can fail the emissions test. Excessive smoke, or readings outside the permitted levels for CO, HC, NOx, and particulates, will lead to failure. This can be caused by issues with the catalytic converter, exhaust sensors, or simply an engine that isn't running efficiently. A diesel particulate filter (DPF) that has been illegally removed or is not functioning correctly can also cause an emissions failure.
Corrosion and Structural Defects
Severe corrosion, particularly on structural parts like the chassis, sills, and suspension mounting points, is a definite fail. The tester will tap areas to check for soundness. Even if a component isn't directly failing, if it's attached to a severely corroded area, it can be a fail. Also, sharp edges caused by rust or damage protruding from the bodywork are dangerous and will cause a fail.
Steering and Suspension Components
Beyond just wear, components like track rod ends and steering arms are checked for excessive play. If there is noticeable looseness in these parts, it compromises steering accuracy and safety. Similarly, any damage to the power steering system, such as leaks or a malfunctioning pump, can lead to a fail.
Seatbelt and Airbag Issues
All seatbelts must be present, easily accessible, and function correctly. This includes retracting properly and locking when pulled sharply. Any signs of wear, fraying, or damage to the webbing, or a faulty locking mechanism, will cause a failure. If a vehicle has an airbag system, the airbag warning light must illuminate on the dashboard when the ignition is switched on and then go out, indicating the system is functional. If the light stays on or doesn't come on at all, it signifies a fault and will result in a fail.
A dodgy MOT test is usually down to one of these very common faults.
Pre-MOT Checks: Avoiding Failure Before You Book
Many common MOT failures can be avoided with a few simple, proactive checks before you take your vehicle to the test centre. These aren't complex mechanical inspections but rather visual checks and basic functionality tests that anyone can perform.
Tyre Condition and Pressure
Check all four tyres for the minimum tread depth of 1.6mm. A simple way to check is to insert a 20p coin into the tread grooves; if you can't see the outer band of the coin, the tread is likely sufficient. Also, inspect tyres for any cuts, bulges, or uneven wear. Ensure tyres are inflated to the correct pressure, as this affects wear patterns and handling.
Lights and Indicators
Walk around your car and test every light: headlights (both main and dipped beam), taillights, brake lights (get someone to press the pedal), fog lights, and hazard lights. Check that all indicators flash at the correct speed and that the dashboard indicators correspond. Replace any bulbs that are not working.
Wiper Blades and Washer Fluid
Ensure your wiper blades are not perished or torn and that they clear the windscreen effectively without streaking. Top up the washer fluid reservoir and check that the jets are spraying correctly onto the windscreen. A clear view is paramount.
Windscreen Examination
Inspect the windscreen for any chips or cracks, particularly in the driver's line of sight. Small chips might be repairable, but larger cracks, especially those within the 'Zone A' area, are likely to cause a failure.
Fluid Levels
Check the engine oil, coolant, brake fluid, and power steering fluid levels. While not directly tested for pass/fail unless critically low or contaminated (affecting safety systems), low levels can indicate underlying issues. Ensure the brake fluid is at the correct level.
Horn Operation
Test your horn to ensure it sounds correctly and clearly. It's a simple check that can prevent a minor failure.
Number Plates
Ensure your number plates are clean, legible, and securely fitted, with no damage that obscures the characters. They must conform to the required standard.
Perform these checks to reduce your chance of an MOT fail list item.
Understanding MOT Defect Categories and Consequences
When your vehicle is tested, any faults found are categorised, which dictates the outcome of the MOT. Understanding these classifications is crucial for knowing what needs to be done to pass.
Dangerous Defects
These are faults that pose a direct and immediate risk to road safety or have a serious impact on the environment. A vehicle with any dangerous defect automatically fails its MOT and must not be driven on public roads until the defect is repaired. The vehicle can only be driven to a pre-arranged repair appointment or to a place of safe storage.
Major Defects
These are faults that are serious enough to potentially affect the safety of the vehicle or its impact on the environment. A vehicle with any major defect will fail its MOT. While not immediately dangerous like the first category, they still require prompt attention and repair. The vehicle can often be driven away from the test centre provided no dangerous defects are present, but it is strongly advised to get the repairs done as soon as possible.
Minor Defects
These are faults that are noted on the MOT certificate but are not severe enough to cause a failure at the time of the test. However, they should be repaired as soon as possible as they could become more serious or lead to a failure in the future. An accumulation of minor defects can also indicate a general decline in the vehicle's condition.
Advisories
These are items that are not defects but are noted by the tester as being close to the minimum standard or likely to require attention in the near future. They are essentially 'heads-up' items. For example, a tyre with tread close to the minimum limit, or a suspension component showing slight wear, might be recorded as an advisory. They don't cause an immediate fail but are important for future maintenance planning.
What Happens After a Fail?
If your vehicle fails the MOT, you will receive a refusal of an MOT test certificate, which details all the faults. You will need to arrange for the necessary repairs to be carried out. Once the repairs are completed, you can then take your vehicle for a partial retest. Depending on the items tested, a partial retest can be a quick process. For example, if only items related to lights or brakes were failed, and those are corrected, the tester may only need to re-inspect those specific components rather than the entire vehicle.
The MOT Testing Manual specifies clear criteria for each defect category.
Specific Failures: Bodywork, Emissions, and More
Beyond the most common checks, certain specific areas or systems can cause an MOT failure if they do not meet the required standards. These often relate to compliance, environmental regulations, or more detailed safety checks.
Body Corrosion (Structural and Non-Structural)
The MOT test differentiates between structural corrosion (affecting the vehicle's integrity) and non-structural corrosion. Areas like the chassis, suspension mounting points, subframes, and seat mountings are checked for excessive corrosion. If these areas are significantly corroded, they will cause a failure. Even non-structural corrosion can cause a failure if it results in sharp edges that could injure pedestrians or occupants.
Exhaust Emissions Explained
For petrol vehicles, the emissions test checks the carbon monoxide (CO) and hydrocarbon (HC) levels, and for diesels, it checks for smoke opacity. These tests are performed on a warmed-up engine. If the readings are higher than the limits specified in the MOT Testing Manual for the vehicle's age and type, it will fail. This can be due to problems with the engine management system, catalytic converter, oxygen sensors, or diesel particulate filter (DPF).
Fuel System Integrity
The fuel system is checked for leaks. Any visible fuel leaks, especially from the tank, pipes, or filter, will result in a failure. The filler cap must also seal correctly and not be damaged. The MOT tester will check for signs of dripping fuel or significant corrosion that could compromise the system's integrity.
Motorcycle Specifics (Brief Mention)
While this article focuses on cars, it's worth noting that motorcycles have their own MOT test criteria, covering aspects like braking, tyres, lights, and emissions specific to two-wheeled vehicles. For example, the MOT test manual for motorcycles covers items like wheel alignment and throttle operation.
Seatbelt Anchorage and Functionality
Beyond the seatbelts themselves, the points where they are anchored to the car's body are also inspected for corrosion or damage. The anchorages must be secure. The testing also includes checking that the seatbelt warning light functions correctly on the dashboard if fitted. A missing seatbelt from a designated seating position will also cause a failure.
Electrical Systems
While MOTs don't test every electrical component, critical items are checked. This includes the battery being securely fitted and any visible damage to wiring that could cause a short circuit. As mentioned, warning lights for systems like ABS and airbags are also checked. The operation of the horn and electric windows (if fitted and required for operation) are also assessed.
A focus on bodywork integrity is key to passing the MOT.
When Is Your First MOT Due?
The timing of your vehicle's first MOT test is determined by its age, not its registration date. Understanding this is crucial for new car owners to ensure they comply with the law.
New Cars and the First MOT
For most new cars, the first MOT test is due exactly three years after the date of registration. This applies to cars, vans, and most other light passenger vehicles. For example, if your car was registered on 15th May 2023, its first MOT would be due on or before 15th May 2026. You can get an MOT test up to one month 'early' (minus one day) and still keep your original renewal date. For instance, if your car is due its MOT on 15th May, you can get it tested on 15th April, and the next MOT will still be due on 15th May the following year.
Exceptions to the Rule
There are some exceptions to the three-year rule. For instance, a motorcycle manufactured on or after 1st September 2018 requires its first MOT one year after it was first registered. Taxis (licence class 3, 4, 5) and some other commercial vehicles may have different rules. Always check the specific requirements for your vehicle type. Vehicles over 40 years old are exempt from MOT testing, provided no substantial changes have been made to them in the preceding 30 years. However, vehicles manufactured before 1st January 1961 are exempt regardless of modifications.
Knowing when your first MOT is due prevents accidental non-compliance.
Can You Drive a SORN Car to an MOT?
Driving a car that is declared as SORN (Statutory Off Road Notification) on public roads is generally illegal, with very specific exceptions. Taking a SORN vehicle to an MOT test is one such exception, but it comes with conditions.
The SORN to MOT Exception
You are legally allowed to drive a SORN vehicle to and from a pre-arranged MOT test appointment. This is one of the few circumstances where a vehicle that is not taxed and insured for general use can be driven on public roads. However, this exception is strictly for the journey directly to and from the test centre.
Conditions for Driving a SORN Car
Crucially, the vehicle must be driven directly to the MOT test centre. You cannot use this exemption to run errands or travel any further than necessary. If the vehicle is found to be unroadworthy during this journey (e.g., it breaks down and requires towing, or is stopped for a clear safety defect), you may still face penalties. Additionally, while the car is declared SORN, it is exempt from needing to be insured, but for the journey to and from the MOT, it is advisable to have at least third-party insurance in place, especially if the MOT is being performed at a garage rather than your home. Driving without insurance is a serious offence, and while the SORN exemption covers the lack of tax, it's wise to clarify insurance status for the specific journey.
Driving a SORN car to an MOT test is permitted, but only directly to and from the appointment.
What to Do if Your Car Fails the MOT
Failing an MOT can be frustrating, but it's a sign that your vehicle needs attention to remain safe and legal. The process following a fail is designed to ensure the necessary repairs are made.
Understand the Refusal Certificate
The first step is to carefully read the refusal of an MOT test certificate issued by the tester. This document clearly lists all the defects that caused the failure, categorised as dangerous, major, or minor. It will also list any advisories.
Repair the Defects
You must have the identified defects repaired. For dangerous defects, the vehicle must not be used on public roads until repairs are completed. For major defects, while you might be able to drive it, it's highly unsafe and not recommended. You can choose to have the repairs done by the MOT test centre, or take the vehicle elsewhere for the work.
Partial Retest Options
Once repairs are completed, your vehicle will need a retest. If you leave the vehicle at the same test centre for repair, it may be eligible for a partial retest, often free of charge, on specific items. If you take the vehicle elsewhere for repairs, you will need to book a retest, which may be a full MOT or a partial retest depending on the centre's policy and the nature of the repairs. Generally, if you take the vehicle back to the same test centre within 10 working days, only specific items might need re-inspecting. If you take it back after 10 working days, or to a different centre, it may require a full test.
Driving After a Fail
You can only drive your vehicle after it has failed the MOT if the previous MOT certificate is still valid and the failure was not due to a dangerous defect, and you are driving it to a pre-arranged repair appointment or test. If your previous MOT has expired, you can only drive the vehicle to a pre-booked MOT test appointment (as detailed in the SORN section), or to a place of repair. Driving otherwise risks fines and penalty points.
When is 1st MOT Due on a New Car?
Remember, if your car is new, its first MOT is typically due three years from its registration date. Ensure you book this in advance to avoid driving with an expired MOT.
Addressing all items on the MOT fail list is essential for safety and legality.