Avoid Engine Damage: Experts Warn Drivers This Week

As temperatures across the UK soar into the 30s this week, drivers face an unexpected risk when starting their vehicles. Automotive expert Kazimieras Urbonas, a Supplier Excellence Manager at Ovoko, cautions that starting cars during peak afternoon heat can significantly damage engines. This warning comes alongside the fourth heatwave of the summer, which has prompted amber health warnings across the region.

The danger lies in the combination of extreme heat and the buildup of heat under the vehicle’s bonnet. Typically, peak temperatures occur between 11:00 and 15:00 in the UK, and during this time, engine bay temperatures can rise 20 to 30 degrees higher than the outside air. When drivers attempt to start their cars after prolonged exposure to such heat, they may be setting the stage for mechanical failure.

Urbonas explains that starting a superheated engine demands even more from the vehicle. “Most drivers don’t realize that their car’s engine bay can reach temperatures far higher than the outside air temperature during a heatwave,” he says. This excessive heat puts strain on the cooling system, which struggles to maintain normal operating temperatures.

When the engine is already hot, the cooling system can become overwhelmed. “Your radiator and cooling fans are working overtime just to maintain normal temperatures,” Urbonas states. “But they’re fighting a losing battle against the ambient heat.” This overheating can lead to severe internal damage, often revealing itself only after significant repairs are needed.

Metal components within the engine behave differently under extreme temperatures, leading to potential warping when subjected to sudden changes. “We see a lot of damaged parts during heatwave periods,” notes Urbonas, highlighting issues such as failed cylinder heads, gaskets, and cooling system components. Repairing these parts can cost hundreds, if not thousands, of pounds.

Certain components are particularly vulnerable to the heat. Rubber seals and gaskets can deteriorate, resulting in coolant leaks and subsequent engine overheating. Urbonas identifies key warning signs that indicate an engine struggling with heat. A higher-than-usual temperature reading at startup is a clear indication of trouble. “If you smell sweet coolant or see steam when you open the bonnet, your cooling system is already under severe stress,” he warns.

Other audible signs can include pinging, knocking, or unusual rattling sounds, all of which suggest that engine components are expanding beyond their normal tolerances. Drivers may also notice their vehicle feeling less responsive or struggling to accelerate, further indicating heat-related issues.

To mitigate these risks, Urbonas recommends a simple yet effective strategy: “Wait 15-20 minutes after peak heat hours before starting your car or take steps to cool it down first.” He adds, “If you must drive during peak heat, start the car and let it idle for a minute or two before driving off to give the cooling system a chance to circulate.”

Preventative measures can save drivers from significant repair costs and inconvenience. Urbonas suggests parking in the shade when possible, using reflective windscreen covers, and regularly checking coolant levels before heatwaves. “Regular maintenance becomes even more important during hot weather,” he advises. Ensuring the cooling system is in peak condition can serve as the first line of defense against heat damage.

Drivers should not ignore warning signs, as minor maintenance issues can escalate into costly repairs. “The cost of a simple coolant top-up or radiator flush is nothing compared to replacing a warped cylinder head or blown gasket,” Urbonas concludes. His insights underscore the importance of proactive vehicle care, especially during extreme heat events.