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Security & TechCommon MOT Failures and How to Avoid Them
By Sun Garage, Owner, Sun Garage · 25 February 2026 · 7 min read
Nearly a third of MOTs fail first time
DVSA figures consistently show that around 30% of MOT tests result in a fail, and the vast majority are down to a small handful of recurring problems – most of which are inexpensive to fix and easy to prevent with a bit of attention beforehand.
Knowing what trips cars up most often means you can check for it yourself, or ask us to look, before you book your test at our West Bromwich centre.
The top failure categories
Year after year, the same categories dominate the DVSA's failure statistics. Understanding them helps you prioritise what to check.
Most common reasons cars fail their MOT:
- Lighting and signalling – blown bulbs, misaligned headlights, damaged lenses
- Tyres – tread below 1.6mm, sidewall damage, incorrect tyre for the axle
- Brakes – worn pads and discs, uneven braking, handbrake efficiency
- Suspension – worn bushes, damaged springs, leaking dampers
- Visibility – cracked windscreens, worn wiper blades, empty washer bottles
- Emissions – excessive smoke or gas readings outside legal limits
Lighting: the easiest fail to prevent
A single blown bulb is enough to fail an MOT outright, yet it takes seconds to check and often minutes to fix. Walk around your car with the engine running and headlights, sidelights, indicators, fog lights, brake lights and reverse lights all switched on, ideally with someone watching from outside.
Number plate lights are easy to forget but are checked just as strictly as headlights.
If a bulb has blown, replace it before your test – most are a five-minute job and far cheaper than a retest fee plus your time coming back.
Tyres and brakes: the safety-critical pair
These two categories account for a large share of failures and are also the components most directly linked to your safety on the road, which is why testers scrutinise them closely.
Tyres
Check tread depth across the full width of the tyre, not just the centre, as uneven wear from poor alignment can leave the edges illegal even when the middle looks fine. Also check for cuts, bulges or exposed cord on the sidewalls.
Brakes
A spongy pedal, the car pulling to one side under braking, or grinding and squealing noises are all warning signs. Brake pads wearing unevenly between left and right is a common cause of failure that is not always obvious from the driver's seat.
Suspension and emissions: the less obvious ones
Suspension faults often develop gradually, so drivers get used to a knock or a slightly softer ride without realising it has become a fail point. Emissions failures can catch out both older petrol cars with worn engines and diesels with clogged particulate filters from lots of short journeys.
If your engine management light is on, do not ignore it before your MOT – the tester is required to note it, and an illuminated light will typically result in a fail regardless of the underlying cause.
How Sun Garage helps you avoid a fail
We offer a pre-MOT check that runs through every one of these common fail points before your official test, giving you time to fix anything we find without the pressure of a booked slot ticking down. If your car does fail on the day, our technicians can usually carry out the repair and retest it the same day.
Call us on 0121 553 0296 or book online, and we will get you through your MOT with the minimum of fuss.