Drivers heading away this summer are being urged to check their vehicles before setting off, after automotive diagnostics specialist Carly revealed the five most common faults affecting used cars that could leave families stranded – and facing repair bills that could exceed the cost of their holiday.
With millions of motorists preparing for long-distance journeys, Carly says many families spend hours planning routes, packing luggage, and organising entertainment for the trip, yet give little thought to the condition of the vehicle that will carry them.
Longer journeys, higher temperatures, fully loaded cars and increased towing demands all place additional strain on a vehicle, meaning relatively minor faults can quickly develop into expensive breakdowns.
Simple Checks Can Prevent Costly Repairs
Before embarking on any extended summer journey, Carly recommends carrying out several straightforward maintenance checks that could significantly reduce the risk of roadside problems.
Drivers should inspect:
- Engine oil level
- Coolant level
- Brake fluid
- Windscreen washer fluid
- Power steering fluid (where applicable)
- Transmission fluid
- Tyre pressures (checked when tyres are cold)
- 12-volt battery condition
These simple checks can help identify issues before they become serious and improve reliability throughout the holiday.
The Five Most Common Summer Breakdown Risks
Using data collected through its diagnostic platform, Carly has identified the faults most frequently affecting vehicles during the warmer months.
1. 12-Volt Battery
High temperatures accelerate battery ageing and increase the likelihood of sudden failure. Internal fluid evaporation and voltage surges can leave drivers unable to start their vehicle.
Typical repair cost: £80–£260
2. Cooling System
Overheating remains one of the most common summer mechanical failures. Low coolant, radiator faults or a failing water pump can rapidly escalate into major engine damage if ignored.
Typical repair cost: £60–£700
3. Air Conditioning
During hot weather, air conditioning systems work much harder than usual. Gas leaks, failed compressors or damaged condensers often require urgent attention to restore cabin comfort.
Typical repair cost: £70–£1,040
4. Engine & Transmission Oil
Extreme temperatures reduce oil effectiveness and lubrication performance, increasing wear on critical engine and gearbox components.
Typical repair cost: £65–£3,020
5. Tyres
Hot road surfaces and rising tyre pressures increase the risk of blowouts and accelerated tyre wear. Regular pressure checks remain one of the simplest but most important safety measures.
Typical repair cost: £85–£700 per incident
Diagnostics Can Detect Hidden Problems Before They Become Breakdowns
For motorists using Carly’s vehicle diagnostics system, a comprehensive health check can identify faults long before dashboard warning lights appear.
The Carly app scans key vehicle systems, detecting issues including engine faults, battery deterioration and sensor errors while the car is still parked on the driveway. Early diagnosis gives drivers the opportunity to arrange repairs before setting off, reducing the likelihood of unexpected roadside failures.
The system also includes a Repair Costs feature, allowing users to describe a fault and instantly receive an estimated repair price covering both parts and labour at either franchised dealerships or independent garages. This helps motorists understand both the likely urgency and financial impact before booking repairs.
Expert View
Emma Brown, UK Growth Manager at Carly, said:
“Summer holidays should be about making memories, not worrying about whether your car will make it to the destination. Carly gives drivers greater peace of mind by helping them identify potential issues before they become costly breakdowns. A quick health check of your vehicle can reveal hidden faults, battery problems or maintenance needs, allowing drivers to address them before setting off.
“By taking a proactive approach to car care and giving motorists greater confidence in the condition of their vehicle, Carly helps make summer journeys less stressful and ensures families can focus on enjoying their holiday rather than dealing with unexpected problems on the roadside.”
Brown added that combining regular maintenance with vehicle diagnostics offers motorists greater confidence that their car is ready for the demands of long-distance summer travel.
Motoring Echo Top Tips: Prepare Your Car Before Your Summer Holiday
Before heading off on your next road trip, make sure your vehicle is ready by following these essential checks:
- Run a full vehicle diagnostic to identify hidden faults before they become major problems.
- Never ignore warning lights, even if they disappear after restarting the engine.
- Check engine oil and coolant levels, topping up where necessary.
- Inspect tyre pressures when cold and examine tyres for damage or uneven wear.
- Test the condition of the 12-volt battery, particularly if it is several years old.
- Use repair cost estimates to understand likely garage bills before booking repairs.
- Seek professional advice if any critical faults are identified before travelling.
- Check lights, brakes and windscreen washers before every long journey.
- Pack for emergencies, including water, phone chargers, a warning triangle (where appropriate), and breakdown contact details.
Motoring Echo Verdict
A summer breakdown can quickly turn an enjoyable family holiday into an expensive and stressful experience. Spending just a few minutes checking your vehicle—or carrying out a full diagnostic scan—could prevent repair bills running into hundreds or even thousands of pounds. As temperatures rise and holiday traffic increases, ensuring your car is road-trip ready is one of the smartest preparations any driver can make.
- You can visit the Carly website and more here: https://www.mycarly.com/
