French mechanics warn against immediate AC use in hot cars to prevent engine failure

During the recent French heatwave, garages across the country reported a surge in vehicle breakdowns linked to the improper use of air‑conditioning. Mechanics observed engine overheating, blown head gaskets, coolant leaks, tire explosions and complete AC failures after drivers turned the system on at full cold while the cabin temperature exceeded 40 °C.

Garagist Yassine Rehar of Vulco in Torcy explained that the sudden temperature drop stresses the cooling system, causing hoses to soften and leak. He and other experts advise drivers to keep windows or doors open for a few minutes to ventilate the interior, drive briefly with windows down to equalise temperatures, and only then switch on the air‑conditioning at a moderate setting—preferably not below 20 °C—to avoid a damaging temperature differential on the engine.

Following these steps is expected to reduce the number of heat‑related repairs and extend vehicle longevity.