Lights, suspension, tyres, brakes and the driver's view of the road account for most MOT failures year after year. Lighting is the most common of all, and it is usually the cheapest and quickest to fix.
Most of the things that fail a car can be spotted in about ten minutes on the driveway. Here are the main culprits and what to look for.
1. Lights and indicators
A blown bulb is the classic. Ask someone to stand behind the car while you press the brake pedal, and walk round to check the headlights, both beams, indicators, hazard lights, fog light and the number plate lights. Bulbs are cheap. Failing for one is the most avoidable way to lose a test.
2. Suspension and steering
Worn bushes, broken springs and leaking shock absorbers fail often. Listen for knocking over bumps, notice if the car bounces more than it used to, or pulls to one side. Uneven wear on a tyre can also be a hint that the suspension needs a look.
3. Tyres
The legal minimum tread depth is 1.6mm across the central three-quarters of the tyre. Cracks, bulges and cuts in the sidewall fail a car even with plenty of tread. Check the pressures too. Our guide to tyre tread depth shows the quick checks.
4. Brakes
Worn pads and discs, seized parts and uneven braking all fail. Squealing, grinding, a soft pedal or the car pulling to one side are the signs. See our post on squealing or grinding brakes. Brakes and tyres are also where most dangerous faults are found.
5. Visibility
A chip in the driver's line of sight, worn wiper blades and an empty washer bottle all cause fails. Replace tired wipers and top up the screen wash before you come in.
6. Things people forget
- The horn does not work.
- A warning light is on, such as the engine, ABS or airbag light.
- The number plates are damaged, faded or spaced wrongly.
- A seatbelt does not lock or release.
- Emissions are over the limit because of a fault or a service that is overdue.
Quick answers
What is the number one reason for an MOT fail?
Lights. A blown bulb or a lens that is damaged is the most common single cause, and it is nearly always cheap to put right.
Will a warning light fail my MOT?
Some will. An engine management, ABS or airbag light can fail the test. Get it looked at before the test, using diagnostic equipment, so you know what it is.
Should I wash the car before an MOT?
It is not required, but a clean car with tidy windows and lights helps the tester see what they need to see.
Can you check my car before the MOT?
Yes. Tell us when you book and we will look it over and quote for anything we find.