NCT Checklist 2026: The Most Common Failures and How to Avoid Them
Every year, thousands of Irish drivers fail the NCT for problems that could have been spotted and fixed in advance. A failed test means a retest, more time off the road, and in many cases a fee you did not need to pay. The good news is that most NCT failures fall into a handful of predictable categories, and nearly all of them can be caught with a proper pre-NCT check.
At Sweeney’s Garage we carry out pre and post NCT checks every week across our Dublin locations, so we see exactly what catches drivers out. Here is what to look at before your test date.
The Most Common NCT Failure Points
Lights and electrics
Faulty or misaligned headlights are consistently among the top NCT failure items in Ireland. A blown bulb is a two-minute fix at the garage, but it is an automatic fail on the day. Check headlights, brake lights, indicators, fog lights, reverse lights and number plate lights before your test, and remember that headlamp alignment matters as much as the bulb working.
Tyres
The legal minimum tread depth in Ireland is 1.6mm, but tyres near that limit, unevenly worn, damaged or mismatched can all cause a fail. Uneven wear often points to a wheel alignment issue, which is worth correcting anyway, as it shortens tyre life and affects handling.
Brakes
Worn pads, scored discs and imbalanced braking performance show up clearly on the NCT brake test rollers. If your car pulls to one side when braking, or you hear grinding or squealing, get it looked at before the test, not after.
Suspension and steering
Worn shock absorbers, bushings and ball joints are common failure items, especially on older cars and on Dublin roads. Knocking sounds over speed bumps or a bouncy, unsettled ride are the usual warning signs.
Emissions
High emissions readings catch out a lot of diesel drivers, particularly cars that mostly do short town journeys. A service beforehand, including fresh oil and filters, gives your car the best chance of passing the emissions test.
Your Pre-NCT Checklist
Before your test, work through the basics: all lights working and clean, tyre tread and pressures checked including the spare where required, windscreen free of significant chips or cracks in the driver’s line of sight, wipers and washers working, seatbelts fully functional, registration plates clean and legible, no warning lights showing on the dashboard, and the car reasonably clean inside and out so the tester can carry out the inspection.
Also bring the right paperwork and remove anything blocking access to the boot floor or spare wheel area.
Failed Your NCT? What Happens Next
If your car fails, the fail sheet will list the items that need attention. Some failures qualify for a free visual retest, while others need a full retest on the machines, which carries a fee. Getting the repairs done promptly matters, because a retest must normally be completed within a set window to avoid paying for a full new test.
Sweeney’s Garage offers a post-NCT repair service at all our locations. Bring us your fail sheet and we will fix exactly what is listed, then have you back for your retest without delay.
Book a Pre-NCT Check With Sweeney's Garage
The cheapest NCT is the one you pass first time. Our pre-NCT check covers lights, tyres, brakes, suspension, emissions and all the common failure points listed above, carried out by experienced mechanics at our garages in Finglas, Ballyfermot and Deansgrange. Book your pre-NCT check today and go into your test with confidence.
