Carrying out DIY checks on your car before you take it for its actual MOT inspection is surprisingly easy to do and could save you money. Passing the test is a legal requirement for all cars more than three years old. But for many of us, the MOT is a bit like having the outside of your home painted; we know we need to do it but we don’t look forward to it because it can bring to light remedial work that will hit the wallet hard.
According to the Driver Vehicle Services Agency (DVSA), which oversees the annual MOT test, around 40 per cent of cars fail. Yet many flunk their MOT for reasons that even a novice mechanic could spot. Follow my tips for your own basic DIY MOT test, and you could stop your car failing on the simplest points.
DIY MOT test: Lights
The majority of cars that fail their MOT test do so because of lights that don’t work. A quick walk around your stationary car should tell you if any lights aren’t working. Make sure you check all the turn indicators and you may need to enlist another person to confirm the brake lights are working while you press the pedal. If your car has foglights, these must be in working order. The lenses covering all bulbs can’t have cracks or chips in them.
If a light isn’t working, it’s probably simply a blown bulb. Your car’s handbook will tell you if it’s possible to replace the bulb yourself and what sort is needed. If it’s a job for a professional, make sure you tell the garage before the MOT test so they don’t fail your car for something you already know about.
DIY MOT test: Suspension
It’s tricky to test a car’s suspension. You can push down on a corner and it should spring up and then settle. Or while you’re driving, listen out for any creaks which could be caused by loose or corroded suspension parts. Neither method is especially scientific but at least they should enable you to warn the garage there’s something wrong before the test. The Gov.uk site has lots of useful information about MOT testing.
DIY MOT test: Brakes
It’s impossible to test a car’s brakes accurately without the right kind of equipment. And brakes can cause an MOT failure for multiple reasons such as excessively worn brake pads or heavily corroded discs. As a DIY test, think about how the car felt when you applied the brakes while driving. Did the steering wheel judder when you hit the brakes? This could be a sign of warped brake discs which are an MOT failure. Does the pedal travel excessively to the floor? This could be an early warning of a hydraulic fault which is also an MOT failure. When you start the car, does the ABS warning light switch off? If it stays on, you’ll fail the MOT.
DIY MOT test: Tyres
You can buy tread depth gauges from any motor retailer. The minimum legal depth is 1.6mm or the outside rim of a 20p piece. In addition, no tyre can have any cracks or bulges in its side walls. Remember to check on the inside of the tyre too. Park on firm ground with the handbrake on, engine turned off and leave the car in gear (or Park if it’s an automatic), before shining your torch underneath – find out more about caring for a car’s tyres in this guide. Finding out if your tyres are legal before the test means you can shop around for replacements at the best price rather than being restricted to what your garage can offer.
DIY MOT test: Glass
You can’t have a chip or crack anywhere within the area swept by the wipers on the windscreen. Outside that area, any damage should be no more than 10mm in diameter. Check the windscreen wiper blades too. The sweeping edge can’t have any bits missing and there can’t be any splits in the rubber either.
Expert advice: How to change your car’s windscreen wipers
DIY MOT test: And finally…
In a previous life I was an MOT tester. I remember testing a Mini Metro once. They were notorious for having rotting rear sub frames. We would drive the cars onto these rollers which would spin the wheels and enable us to test the brakes. Metros were front wheel drive and I remember when I drove one out, the sub frame broke away leaving the rear wheels in the rollers and me driving a two-wheeled car. Thankfully, cars aren’t that bad these days!