Surprising MOT Test Failures
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Surprising MOT Test Failures

Surprising MOT Test Failures
Surprising MOT Test Failures That Many UK Drivers Still Don’t Know About
Over the years at Pellon Tyre and Autocentre, we have seen plenty of motorists genuinely surprised when their vehicle fails an MOT test for something they never realised could actually be a problem.
Most people expect MOT failures to involve things like:
- worn tyres
- faulty brakes
- broken suspension
- exhaust problems
But modern MOT testing now includes many smaller safety and visibility checks that some drivers may never even think about.
One thing that still surprises many customers is that even something as simple as an air freshener hanging from the mirror can potentially become an MOT issue.
Air Fresheners and Windscreen Vision Problems: Surprising MOT Test Failures
This is probably one of the most common “surprise” MOT issues we come across.
Drivers often hang out:
- air fresheners
- fluffy dice
- parking permits
- ornaments
- sat nav holders
from the rear-view mirror area without thinking twice about it.
However, MOT rules are very clear about the driver’s field of vision through the windscreen.
If an item obstructs the driver’s view of the road, it can become an MOT failure or at the very least an advisory.
In reality, most MOT testers will simply remove the item before testing where possible, but large objects hanging in the swept area of the windscreen can definitely create problems.
This is especially important on busy roads around Halifax, where visibility is already affected by hills, junctions and poor weather conditions.
Warning Lights Are Now Taken Much More Seriously
Years ago, many warning lights were ignored by motorists without too much concern.
Modern MOT testing is very different.
Today, illuminated warning lights relate to the following:
- airbags
- ABS brakes
- electronic stability control
- tyre pressure monitoring systems
can all lead to MOT failures.
We often see customers arrive saying the following:
“The car drives perfectly.”
But if a critical dashboard warning light remains illuminated, the vehicle may still fail.
Modern cars rely heavily on electronic safety systems, and MOT regulations have evolved to reflect this.
Tyres Are Under More Scrutiny Than Ever: Surprising MOT Test Failures
Tyres have always been important during MOT testing, but modern inspections now pay close attention to several additional areas.
It is not just about tread depth anymore.
Vehicles can fail for:
- damaged sidewalls
- incorrect tyre sizes
- tyres fouling suspension components
- cords exposed
- severe cracking
- mismatched tyre types on certain vehicles
At Pellon Tyres, we regularly see tyres damaged by potholes around Calderdale without drivers even realising it.
The roads around Halifax can be particularly harsh on tyres due to potholes, kerbing and steep road surfaces.
Number Plates Can Cause MOT Problems
Many drivers are unaware that number plates themselves are checked closely during MOT testing.
A vehicle can fail for:
- incorrectly spaced lettering
- faded plates
- cracked plates
- delaminated plates
- missing characters
- dirty or unreadable plates
Tinted covers and decorative fonts are also becoming increasingly scrutinised.
This is particularly common with modified vehicles.
Windscreen Washer Problems: Surprising MOT Test Failures
Another surprisingly common failure item is the humble windscreen washer system.
If:
- washer jets fail
- the bottle is empty
- washers are blocked
- wipers smear badly
the vehicle may fail the MOT.
Many drivers only discover the washers are not working properly when the tester checks them during the inspection.
With Yorkshire weather often producing muddy roads, proper screen cleaning is an important safety feature.
LED Bulbs and Modified Lighting
Modern LED conversions have also created new MOT complications.
We regularly see vehicles fitted with aftermarket LED headlight bulbs that were never designed for the original headlamp units.
In some cases:
- beam patterns become incorrect
- glare affects other drivers
- light output becomes unsafe
Certain poorly fitted LED upgrades can now result in MOT failures.
Seat Belts and Interior Problems: Surprising MOT Test Failures
Something as simple as a twisted seat belt or faulty seat adjustment can also create MOT issues.
Modern MOT tests include checks for:
- seat belt operation
- secure seat mountings
- damaged buckles
- warning systems
- front seat adjustment
Many people do not realise that interior safety systems are now inspected much more carefully than they were years ago.
Dirty Emissions and Diesel Smoke Tests
Diesel vehicles in particular now face stricter emissions testing.
One issue we increasingly see is diesel particulate filter (DPF) trouble, especially on cars mainly used for short journeys around Halifax.
Short local trips often prevent the DPF system from regenerating correctly, eventually leading to:
- warning lights
- excessive smoke
- failed emissions tests
Modern emissions systems are far more sensitive than older vehicles ever were.
Dash Cameras and Phone Mounts
Another modern issue involves dash cameras and mobile phone holders.
These devices are extremely popular now, but poor positioning can obstruct the driver’s field of vision.
Large mounts fitted within the swept area of the windscreen may potentially create MOT concerns.
Again, many motorists are completely unaware of this.
Simple Checks Can Avoid MOT Surprises
One thing we always advise local motorists is that many MOT failures can easily be avoided with a quick pre-test inspection.
Checking simple items beforehand can save both time and money.
Before your MOT:
- check all lights work
- remove large hanging objects
- top up washer fluid
- inspect tyres
- clear dashboard warning lights where possible
- ensure number plates are readable
These small checks often make a big difference.
MOT Testing Has Changed Considerably: Surprising MOT Test Failures
Modern MOT testing is far more detailed than many motorists realise.
Vehicles today contain:
- more electronics
- more safety systems
- more emissions controls
- more driver assistance technology
As cars evolve, MOT testing evolves alongside them.
At Pellon Tyre and Autocentre, we regularly help customers prepare for MOT tests and explain some of the lesser-known rules that often catch drivers out.
Final Thoughts
The air freshener hanging from the mirror may seem harmless, but it is a perfect example of how modern MOT testing now focuses heavily on safety and driver visibility.
Many MOT failures today involve smaller issues motorists simply never realised were important.
Fortunately, most are easy to fix once identified.
A little preparation before the MOT test can often prevent unnecessary failures and keep vehicles safely on the roads around Halifax and Calderdale.
