Common Car MOT Fails and How You Can Avoid Them!​

Passing your MOT test with no advisories is a euphoria we rarely experience, let alone expect. When we think about the many ways a car can fail a test, it’s easy to think that randomness and luck play a big part in whether something under the bonnet will go pop or not. However, over the years some common themes have popped up which are golden nuggets for everyday drivers. Join us below to look at some common MOT fails and how to look out for them.​

Common MOT Failures

By looking at data from the DVSA (they oversee the MOT for all cars in the UK, among other things), we can find out the failures that pop up the most. As you’ll see, they aren’t as obscure as you’d expect, with many of them being preventable/avoidable with a few tips included. Of course, this isn’t an exhaustive list, but below includes the most common MOT fails.

Lights and Other Electrical Equipment: From a blown bulb to a dodgy indicator, it’s easy to see why poor electrics make up a large portion of MOT failures. Cars won’t work without their electrical system in shape, which is why it’s so important to check everything is working before taking it to an MOT. Lights are easy to check for and replace yourself, like the brake lights, headlights, and indicator lights (you can also double check whether they are cracked too). Other electrics might be a bit harder to replace, but you can still check them with their respective switches. Don’t forget about your horn either, as a broken one can fail your MOT.

Suspension: Potholes can be unavoidable sometimes, and while you may have come through scotch-free, your suspension might not have been so lucky. Uneven road surfaces, speed bumps and off-road conditions are all culprits of a failed MOT. Suspension failures are hidden well, but you can listen for odd sounds while driving or even look at how your car rests – is it sitting flat against the road? Is it too bouncy if you press on a corner? The best way to avoid suspension failure is to treat your suspension kindly. Avoiding potholes where you can, going slow over speed bumps and not taking a two-wheel drive in off-road conditions is a good start to have your suspension passing your MOT test with flying colours!

Brakes: Failing brakes are simple to spot. If they squeak when you try to slow down, then that might be a sign they are on their way out. It might not mean they are failing, as many brake pads deteriorate with use and the noise is a sign of that, but if it’s a severe sound, or high pitched, or grinding, you should probably get it looked at. Also, if your car pulls to one side when braking, or the brake pads in your wheel doesn’t look smooth or are thin then you might have a problem. The handbrake of your car can also be a devil – try to use it on a hill when parked to check if it can fully immobilise the car.

Tyres: Checking your tyres should occur a lot more frequently than your annual MOT, especially when the climate or temperature changes or reaches an extreme. You can start by checking the tread with a simple trick. Grab a 20p coin and slot it into your tyre’s tread – if the outer band of the coin is hidden (i.e., if the coin sinks 1.6mm into the tread up to its inner picture) then your tyre is at the legal tread depth. Other checks you can make are the inflation levels, where underinflated tyres can cause your car to pull to one side, increase fuel consumption, and possibly endanger others. Lastly, check for any cuts, lumps, or irregularities on the tyre – even the smallest flaw can develop into something else over time and fail your MOT.

Driver Visibility: This is a big one and it’s easy to see why poor visibility can fail an MOT. Even sat-navs stuck to the inner windshield or air fresheners can be seen as blocking the driver's visibility. More obvious failures will be cracks or chips in the glass within the driver's eye line – even if it’s only 10mm in size. Cracks that are 40mm in size, even on the far left of the windscreen, can fail an MOT. While you’re here, check that the opening mechanism of the bonnet is working – is there any chance it could unlatch? Wipers shouldn’t go unnoticed either. If they are scratching/smudging the glass or not working properly, you should get them checked. Another unnoticed but common MOT fail is the visibility of the car’s number plate – if it’s faded or deteriorated then this might fail your MOT.

Failing an MOT Test

Failing an MOT isn’t ideal, but life gets a lot easier if you know what comes next so you can get back on the road as quickly and safely as you can. We are here to help you with that.

After failing an MOT, you’ll be given a VT30 Refusal of an MOT Test Certificate. Inside, you’ll find out why exactly your car failed the MOT, and this information will be uploaded to the DVLA database. Receiving a VT30 means your car isn’t road safe and needs fixing before you can take it back out on the road again. Keep the VT30 as you will need it to retest your vehicle after it has been fixed. If, for whatever reason, you wish to appeal the decision made by the MOT test mechanic, you will need to keep the VT30 form handy, fill out a complaint form, and send it to the DVLA.

Can I drive my car if it fails an MOT? A car that has failed an MOT is illegal to drive. If it’s not deemed roadworthy, you can’t even drive it to be repaired at a mechanic or to another MOT centre – only roadworthy cars can be driven there. Your MOT advisor will notify you of your options after the test. Your next step is to get your car repaired so it can be roadworthy or even fully repaired. MOT test centres sometimes have repair shops, and you can find out if they can fix it for you. If not, you will need to book an appointment with a mechanic.

If you take a car for repairs and return it to the MOT test centre within one day, it’s possible for a partial retest to be conducted, but you’ll need to speak to your MOT tester first. Some MOT testers will allow for a partial retest if you bring your car back repaired within 10 working days, but again, this is something specific to test centres.