Summer is one of the busiest times of the year for both drivers and garages. Longer journeys, holiday travel, and higher temperatures can all place additional strain on your vehicle, making existing faults more likely to develop into MOT failures.
Many of the issues that cause a failed MOT, from worn tyres to brake wear and damaged windscreens, can be identified and resolved before your test. With decades of experience inspecting and maintaining vehicles, the team at Pantech Auto Technicians understands the faults that commonly appear after a busy summer of driving.
This guide explains the most common summer MOT failures, why they occur, and the simple checks you can carry out to improve your chances of passing first time.
Key Takeaways
- Increased summer mileage can accelerate wear on tyres, brakes, and suspension, making them more likely to fail an MOT.
- Hot weather can worsen existing issues, including windscreen damage and cooling system faults that may trigger dashboard warning lights.
- Simple maintenance checks before your MOT can help identify problems early and reduce the risk of an unexpected failure.
- Booking an MOT alongside routine servicing gives any necessary repairs time to be completed before your test.
1. Worn Tyres After Increased Summer Mileage
Whether you’re heading off on holiday, planning weekend day trips, or simply making the most of the longer days, the extra mileage can accelerate tyre wear. Higher road temperatures can also place additional stress on tyres, increasing the risk of damage if they are already worn.
During an MOT, tyres are checked for the legal minimum tread depth of 1.6mm across the central three-quarters of the tyre. The tester will also inspect for cuts, bulges, exposed cords, and any other defects that could affect safety. If any tyre fails to meet these standards, your vehicle will fail its MOT.
How to Prevent
Inspect your tyres regularly throughout the summer months. Check the tread depth, look for visible signs of damage, and ensure each tyre is inflated to the correct pressure. Replacing worn tyres before your MOT will improve your chances of passing and make your vehicle safer for long journeys.
2. Cooling System Problems and Engine Warning Lights
Warm weather puts extra pressure on your vehicle’s cooling system, particularly during long journeys or when sitting in slow-moving holiday traffic. Low coolant levels, leaking hoses, or a failing radiator can cause the engine to overheat, often triggering the engine management warning light.
While the cooling system itself is not directly tested during an MOT, an illuminated engine management light can fail in many modern vehicles. Ignoring overheating issues can also lead to more serious and expensive mechanical damage.
How to Prevent
Check your coolant level regularly before longer summer journeys and watch for signs of overheating, such as rising engine temperatures or steam from under the bonnet. If a warning light appears on your dashboard, arrange a diagnostic inspection before your MOT rather than hoping the issue will resolve itself.
3. Worn Brakes After Longer Summer Journeys
The increased mileage that comes with summer driving places greater demands on your braking system. Frequent motorway driving, stop-start traffic, and carrying extra passengers or luggage can all accelerate wear on brake pads and discs.
During an MOT, the braking system is thoroughly inspected to ensure it performs safely and efficiently. Excessively worn brake pads, damaged discs, brake fluid leaks, or poor braking performance can all result in a failed test.
How to Prevent
Pay attention to warning signs such as squealing, grinding, vibrations when braking, or increased stopping distances. If you notice any changes in braking performance, have your vehicle inspected before your MOT to replace worn components before they become a reason for failure.
4. Windscreen Damage Made Worse by Summer Heat
A small windscreen chip may seem insignificant, but summer temperatures can cause existing damage to spread. Repeated heating and cooling of the glass, particularly when using air conditioning after the vehicle has been parked in direct sunlight, can quickly turn a minor chip into a larger crack.
During an MOT, the windscreen is inspected to ensure any damage does not obstruct the driver’s view or exceed the permitted size limits. Damage within the driver’s field of vision is a common reason for failure.
How to Prevent
Inspect your windscreen before your MOT and repair small chips as soon as possible. Addressing minor damage early is usually quicker and more cost-effective than replacing the entire windscreen once the crack has spread.
5. Faulty Lights That Go Unnoticed During Longer Days
With more daylight during summer, many drivers use their vehicle lights less frequently. As a result, a blown bulb can easily go unnoticed until the day of the MOT.
The MOT includes checks on headlights, brake lights, indicators, reversing lights, rear lights, and number plate lights. Every required light must work correctly, display the correct colour, and be securely fitted for the vehicle to pass.
How to Prevent
Test all of your vehicle’s lights before your MOT, including the brake lights and indicators. Replace failed bulbs promptly and clean any dirty or cloudy light lenses to ensure they remain clearly visible.
6. Worn Wiper Blades and Washer Problems
Although summer is generally associated with dry weather, bright sunshine, dust, pollen, insects, and sudden heavy showers can all reduce visibility. Extended exposure to heat and sunlight can also cause rubber wiper blades to harden, crack, or split.
During an MOT, the tester will check that the wipers clear the windscreen effectively and that the washer system operates correctly. Damaged blades or an empty washer bottle can both contribute to a failed test.
How to Prevent
Replace wiper blades if they leave streaks or fail to clear the windscreen properly. Keep your washer fluid topped up with a suitable screen wash and check that the washer jets spray evenly across the glass before your MOT.
7. Suspension Wear Revealed During Summer Driving
Longer journeys often make suspension problems easier to notice. If your vehicle feels less stable, produces knocking noises over uneven roads, or bounces excessively, worn suspension components may be the cause.
An MOT tester will inspect springs, shock absorbers, and other suspension components for wear, damage, and excessive movement. Faults affecting the suspension can reduce vehicle stability and result in an MOT failure.
How to Prevent
If your vehicle’s handling has changed or you’ve noticed unusual noises while driving, arrange an inspection before your MOT. Replacing worn suspension components early can improve comfort, safety, and the likelihood of passing your test.
8. Dirty or Damaged Registration Plates
Summer driving often leaves registration plates covered in insects, dust, and road grime, particularly after motorway journeys. While dirt alone may not always result in an MOT failure, cracked, faded, or incorrectly displayed plates can.
During the MOT, both registration plates must be securely attached, easy to read, correctly spaced, and comply with current legal standards. Plates that are obscured or difficult to identify may cause the vehicle to fail.
How to Prevent
Give your registration plates a thorough clean before your MOT and inspect them for signs of damage or fading. If they have become cracked, difficult to read, or no longer meet legal requirements, replace them before your test.
Also read: MOT FAQs: Everything You Need to Know Before Your MOT
Get Your Car Ready for Its Summer MOT
Preparing your car before its MOT can help you avoid unexpected failures, reduce repair costs, and keep your vehicle safe for summer driving. If you’ve spotted any of the warning signs covered in this guide, or your MOT is approaching, having your vehicle checked by an experienced technician can make all the difference.
Pantech Auto Technicians has been supporting drivers across Guildford and the surrounding areas since 1991. As a family-run garage, the team is known for providing honest advice, dependable workmanship, and a friendly, personal service. As an approved Trust My Garage member and part of the Retail Motor Industry (RMI), customers can book with confidence.
Whether your vehicle needs routine maintenance or repairs before its MOT, a wide range of services is available:
- Guildford MOT testing
- Vehicle servicing
- Tyre replacement and repairs
- Brake inspections and repairs
- Wheel balancing
- Air conditioning servicing
Booking your MOT alongside any necessary servicing or maintenance can help identify issues early, giving you the best possible chance of passing first time and keeping your car ready for every summer journey.
