The UK has seen record-breaking temperatures this summer, and while most of us have been grateful for the sunshine, your car has been working harder than you might realise. Heat causes more hidden damage to vehicles than cold weather does, and with autumn on its way, now is the right time to check what the season has left behind.
Here is what a long, hot summer actually does under the bonnet.
Your battery
The most common misconception about car batteries is that winter kills them. In reality, it is usually summer that does the damage. Heat accelerates the chemical reactions inside the battery, causing the fluid to evaporate and the internal components to degrade faster. When temperatures under the bonnet climb to 60 degrees or more on a hot day, even a relatively young battery takes a hit.
Winter then delivers the final blow to a battery already weakened by months of heat. The breakdown call in January often traces back to a battery that spent July and August slowly deteriorating.
If your battery is over three years old, or if you have noticed the engine turning over more slowly on startup, get it tested before October. Battery testing at Motorsector takes a few minutes and could save you a roadside call-out.
Your tyres
Heat affects both tyre pressure and tyre condition. As temperatures rise, the air inside the tyre expands, which can push pressure beyond the recommended level. Overinflated tyres wear unevenly and reduce grip, particularly in the wet conditions that come with autumn.
High temperatures also soften the rubber compound, speeding up wear. After a summer of record heat and long journeys, it is worth checking tread depth on all four tyres. The legal minimum is 1.6mm across the central three-quarters of the tread. Insert a 20p coin into the groove. If the outer rim of the coin is visible, the tyre is below the legal limit.
Check the sidewalls too, for small cracks or bulges. These can develop in heat-stressed rubber and indicate the tyre is approaching the end of its safe life.
Your coolant
Your cooling system works hardest in summer traffic, and coolant degrades over time. Old or low coolant cannot manage heat as efficiently as fresh fluid, which means your engine runs hotter than it should. After the temperatures we have seen this year, if your coolant has not been changed in the last two years, now is the right time to do it.
You can check the coolant level yourself when the engine is cold. The reservoir is clearly labelled under the bonnet on most vehicles. If it is low, top it up with the correct mixture for your car. If you are not sure what that is, bring it in and we will check.
Your air conditioning
If your air conditioning was working hard all summer, the refrigerant level will be lower than it was in spring. AC systems lose gas gradually, and a system that felt fine in June might struggle next year. A regas is quick and inexpensive, and booking it now means it is ready rather than discovered broken on the first warm day of 2027.
Your wiper blades
Wiper blades take a beating in summer heat. The rubber dries out, hardens and can start to split or streak. Autumn brings wet roads almost immediately, so this is one of the easiest checks to do before the season changes. If they smear or leave a dry patch, replace them.
Book an autumn health check
At Motorsector in Streatham, we carry out a full visual inspection as part of every service, including footage from underneath your vehicle so you can see the condition of key components for yourself. If you want a quick pre-autumn check rather than a full service, call us and we can talk through what makes sense for your car and your mileage.
Book online at motorsector.com or call us on 020 3981 1781.