Why MOTs Fail & How to Avoid It

An MOT test is a legal requirement for most vehicles over three years old in the UK, ensuring they meet road safety and environmental standards. However, many cars fail their MOT for avoidable reasons. Understanding the common causes of failure can help you prepare in advance and save money on unnecessary repairs.

Top Reasons Cars Fail Their MOT

1. Faulty Lights & Indicators

🚨 Nearly 30% of MOT failures are due to broken or faulty lights. This includes headlights, brake lights, indicators, and number plate lights. Check all your lights regularly and replace any bulbs that aren’t working.

2. Worn or Damaged Tyres

🚗 Tyres must have a minimum tread depth of 1.6mm and be free from cuts, bulges, or other damage. Use a 20p coin test to check your tread depth – if the outer band of the coin is visible, your tyres may need replacing.

3. Brakes Below Standard

🛑 Brake pads and discs wear down over time. If you hear squeaking, grinding, or if your car takes longer to stop, get your brakes checked before the test.

4. Poor Visibility – Wipers & Windscreen

👀 A cracked windscreen or faulty wipers can result in a failure. Check for any cracks larger than 10mm in the driver’s view and ensure your wipers clear the screen properly.

5. Exhaust Emissions Issues

🌫️ High emissions due to engine problems or a faulty exhaust system can cause an MOT failure. Regular servicing and using premium fuel occasionally can help keep emissions low.

6. Suspension & Steering Problems

🔧 Worn-out shock absorbers, damaged suspension components, or issues with power steering can lead to a fail. If your car feels bumpy or hard to steer, get it checked before the MOT.

How to Avoid an MOT Failure

✅ Do a Pre-MOT Check – Go through this list a few weeks before your test.

✅ Book a Pre-MOT Inspection – At Car Friend, we offer pre-MOT checks to catch small issues before they become big problems.

✅ Keep Up with Regular Servicing – Routine maintenance reduces the risk of failures and expensive repairs.

✅ Check Fluids & Top-Up Where Needed – Brake fluid, engine oil, and washer fluid levels should be checked before the test.

Book Your MOT With Confidence

Avoid MOT failure and unnecessary repair costs by booking your MOT with Car Friend. We provide expert testing, pre-MOT checks, and transparent advice to keep you safely on the road.

🚗 Book Your MOT Online Today!