10 Surprising Reasons Your Car Could Fail Its MOT

Less Obvious Ways to Fail an MOT

Although far from being one of the most expensive aspects of maintaining a car, the MOT is nonetheless unavoidable if you want to keep your 3+ year old vehicle on the road. Add to this the inconvenience of failing the test, getting remedial work done, and getting a restest then it makes even more sense to be prepared and address the most likely causes of MOT failure before the test.

That's all well and good when it comes to the obvious reasons - brakes, tyres, lights - but what about the more obscure and in some ways surprising reasons for a car to fail an MOT? Let's take a look.

1. A badly positioned air freshener

What we're really talking about here is things that get in the way of clear vision. Hanging accessories or other objects can obstruct the driver's view. However, the obstruction must meet the relevant MOT criteria; not every air freshener will cause a failure.

2. A faulty bonnet catch

We might not consider this at all but it's a bit of a no-brainer when given due consideration. A bonnet that cannot be secured properly can be a serious safety issue. A bonnet at risk of popping openwhile driving can result in a dangerous defect, and be the potential cause of an accident that doesn't bear thinking about.

3. An empty screenwash reservoir

This may not seem feasible in the UK given our wonderful weather, but yes, drivers do sometimes forget or neglect to top it up. This is a straightforward matter - the washer system must work sufficiently to help the wipers clear the windscreen.

4. A number plate light that's stopped working

Without the proverbial "eyes in the back of the head", drivers might not notice that their rear registration plate is no longer illuminated, particularly if they rarely drive in the dark, and it's not likely to be pointed out - unless a kindly patrol car guides a driver to this fault.

5. A dashboard warning light

It's always on, car seems to drive fine - nothing to worry about, right? Think again. Depending on the warning and the system involved, a persistent warning can result in an MOT failure. ABS, airbag and engine-management faults are worth explaining carefully, and there could be more serious issues at play here that could cost more than just an MOT failure.

6. A damaged or ineffective horn

This is something that may rarely come to light, depending on driving style. For more mild-mannered motorists, it may rarely be used, but it is still a testable safety item.

7. A seat belt that doesn't retract properly

A belt that appears intact may still have a fault with its operation, fastening or retraction. This is, of course, another serious safety issue not to be dismissed.

8. A windscreen chip in the wrong place

Returning to the subject of clear, unobstructed vision, the location of a windscreen chip matters as well as the size. Damage in the driver's critical field of vision is subject to stricter limits. For example, the MOT rules generally allow no more than 10mm of damage in Zone A, compared with 40mm elsewhere in the swept area of the windscreen, subject to the applicable assessment criteria. Damage outside those limits does not automatically mean every windscreen will fail; the effect on the driver's view matters too.

9. An insecure battery or exposed electrical wiring

The battery and visible electrical wiring are among the items inspected, so problems that aren't obvious during everyday driving can still be picked up. This is where it pays to lift the bonnet every so often to check out for wear and tear that may not make a difference to the way the car runs, superficially at least, but can actuallly be the beginning of a more serious fault.

10. A steering lock fault

The steering lock mechanism and relevant warning lights are inspected. A fault may be present even when the car seems to drive normally.

These are all grounded in the official MOT inspection requirements, although the precise failure criteria differ between items. But bear in mind one overall principal: your car might have a fault you haven't noticed because you never use the equipment. For example, a faulty horn, ineffective washer jets or a rear number plate light can go unnoticed for months.

So in conclusion: before the test, spend five minutes checking the equipment you don't necessarily use every day.

Busting a Myth: will a car fail the MOT if the rear wash wipe is faulty?

No, a car won't normally fail its MOT simply because the rear wash-wipe isn't working.

The important distinction is between the front windscreen wipers and washers, which are part of the MOT test, and the rear wash-wipe, which generally isn't subject to the same inspection requirements.

A faulty rear washer or wiper might be inconvenient, but it isn't automatically an MOT failure just because it doesn't work.

The official guidance

The UK government's MOT inspection manual, Section 3: Visibility specifies that the relevant wiper and washer requirements concern the windscreen at the front. A rear wiper is not a mandatory MOT test item.

One qualification: if a rear wiper has damaged the rear glass so badly that it creates a separate visibility or safety issue, that issue could be assessed on its own merits.

So in conclusion, "Will a faulty rear wiper fail your MOT?" The answer is generally no, although it's still worth keeping it in working order for safe driving.

MOTs at Dowleys

If you are concerned about any of the MOT-related points raised in this article, or just generally need to get your MOT done, contact the MOT experts here at Dowleys for professional advice and outstanding service.