Winter gets all the attention when it comes to breakdowns, but summer presents its own set of risks — and some of them are more serious. London’s summer temperatures, combined with heavy traffic, air conditioning use, and fully loaded cars heading for weekends away, create the perfect conditions for certain types of breakdown. Here’s what to watch out for.
1. Engine Overheating
The number one summer breakdown cause. When London grinds to a halt in 30°C+ heat, your engine’s cooling system works at maximum capacity. A weak spot — low coolant, a failing water pump, a stuck thermostat, or a perished hose — will be exposed. Never remove the radiator cap when the engine is hot; wait at least 30 minutes. Steam or a temperature gauge in the red means stop immediately.
2. Air Conditioning Failure
While not technically a breakdown, an air conditioning failure on a hot day in London traffic can be miserable and potentially dangerous, especially for children, elderly passengers, or pets. AC systems lose refrigerant gradually. An annual AC service ensures it’s working when you need it most.
3. Tyre Blowouts
Hot roads increase tyre pressures. An already weakened tyre — with a slow puncture, sidewall damage, or worn tread — is at higher risk of a blowout in summer, particularly at motorway speeds. Check your tyre pressures before long journeys. Our flat tyre assistance team sees a spike in call-outs on the hottest days.
4. Battery Failure in Heat
It’s not just cold that kills batteries. High temperatures accelerate the chemical reactions inside a battery, causing internal corrosion and fluid evaporation. A battery that struggled through winter may finally fail in the first summer heatwave.
5. Fuel Vaporisation (Petrol Engines)
On older petrol vehicles, extreme heat can cause fuel to vaporise in the fuel lines before reaching the engine, leading to vapour lock. The engine cranks but won’t start, especially after a hot soak. Modern fuel-injected cars are less susceptible, but it remains an issue for classic cars and older vehicles.
6. Exhaustion and Dehydration of the Driver
While not a mechanical breakdown, a driver suffering from heat exhaustion is a safety risk. Keep water in the car, use sunshades when parked, and take regular breaks on long journeys.
Summer Road Trip Preparation
Before heading out of London for a summer road trip: check coolant, oil, screenwash, and tyre pressures; test the air conditioning; pack water, snacks, and a phone charger; and save 020 8088 9680 in your phone for emergency recovery.
If summer heat catches your car out, our London recovery team is ready 24/7. Don’t risk driving an overheating engine — call for professional help instead.