Car Warning LightsNCT

NCT failures that could have been avoided

Published: 11/19/2021

Almost half of all primary NCT tests result in a ‘fail’. That’s a very high statistic and although the Road Safety Authority have not issued any up to date statistics, we do know that over a million cars failed the NCT in 2019. Most of these test failures could have been avoided by some simple checks. It is always a good idea to drop your car in for a pre-test check with your local mechanic and it is worth remembering that although the NCT is a fairly comprehensive test, it never replaces getting the car properly serviced.

Front Suspension

This is one of the main reason for NCT failures. If there is more than a 30% difference between the left and right side of the vehicle it is a likely fail. Imbalance in the suspension is pretty serious as it affects your handling and braking. If you hear clunking or creaking noises as you drive, it might be wise to have the suspension looked regardless of whether there is an impending NCT test or not

 Misaligned headlights and Missing Bulbs

One of the most common reasons for NCT failure is a bulb not working or the headlights badly adjusted. The misaligned lights can happen when a bulb is being replaced. It is easily sorted out for you by your local friendly mechanic. At least get a friend or family member to check that all lights, indicators and brake lights, are working before you set off for the dreaded test.


The tread on your tyres must be more than 1.6mm and the tyres themselves need to be in good condition, without bulges or damage. What some drivers are not aware of is that the tyres must be of the same type and size on both of the front wheels and on both of the back wheels. 


Extensive corrosion or rust on the body of the car will meet with a fail, but the test also looks at the exhaust system, where rust may cause the noise emission failure, and at cracked mirrors and jagged or damaged panels which may bring a fail too.

Registration Plates

This is one that older cars often fail on as wear and tear from the road causes damage to the plate. The plates must be black on a white background and easily read. We have heard of fails due to illegible or wrong sized letters and numbers and in some cases a quick refresh with a bottle of office typing correction fluid will see the test through to a positive end. 98 thousand vehicles failed their test in 2019 because the registration plate lamp was not functioning.

Brake Line and Hose

Unsurprisingly, the NCT is tough on brake lines. It is essential that the brake hose is in good order, and not just when an NCT test is looming. Rusted, broken or damaged brake hoses account for a great many fails at the NCT test centers. 

The Road Safety Authority have issued a new manual which details everything you should know about the rigors and demands of the Irish NCT system. It is 157 pages long and details every possible fail on your vehicle and the severity of that fail.  It’s not particularly interesting bedtime reading for most people and it is much simpler and effective to submit your car to a pre-test service prior to the test. Any of our fine talented mechanics here at Peter Hanley Motors will be happy to assist in getting an NCT pass and avoid the inconvenience and the cost of retesting. The NCT can be a worrying time for a lot of motorists. Reduce the worry and the chance of a failure by being prepared and book a car service check up today.

Peter Hanley Motors is a registered
member of The Society of the Irish
Motor Industry

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