According to DVSA data, around one in five cars fails its MOT every year in the UK. A significant proportion of those failures are for issues the driver could have spotted and fixed before the test. Here are the most common reasons.
1. Lights not working
Lighting faults are consistently the most common MOT failure reason. A single blown bulb in a headlight, brake light, indicator or number plate light is an automatic failure. Walk around your car once a month and check every light is working.
2. Tyres below the legal minimum
Tyre tread below 1.6mm across the central three-quarters is a failure. Check your tread depth before booking your MOT. If a tyre is borderline, it is far cheaper to have it replaced in advance than to fail and pay for a retest.
3. Windscreen damage
A chip or crack larger than 10mm in the driver direct line of sight is a failure. Any damage larger than 40mm anywhere in the swept area of the wipers is also a failure. Small chips can often be repaired quickly and cheaply by a windscreen specialist before the test.
4. Wiper blades not clearing properly
Wiper blades that smear, streak or miss sections of the windscreen are an MOT failure. Blades typically need replacing every 12 to 18 months.
5. Brakes below required efficiency
Brakes are tested on a rolling road. Worn pads, seized calipers or corroded discs are common causes of failure. If your brakes feel soft, pull to one side or make noise, have them checked before your MOT.
6. Steering or suspension issues
Worn ball joints, track rod ends, wishbone bushes and wheel bearings all show up during the MOT. Warning signs include clunking over bumps, vague steering, uneven tyre wear or vibration through the wheel.
7. Emissions failure
A car that has not been serviced recently or that has an engine management fault is more likely to fail on emissions.
A quick pre-MOT checklist
Check all lights; check all four tyres for tread and visible damage; check the windscreen for chips and cracks; check wiper blades clear the screen cleanly; check the horn works; check your number plates are clean and secure.
We carry out a free pre-MOT visual check when you drop your car off at Steins Garage. Book your MOT here or call 0131 554 3423.