Why you may find a pool of water under your car in hot weather

By Richard Aucock, Motoring Research

With the summer weather now finally turning into a heatwave, some drivers may be alarmed to find pools of water beneath their cars – sometimes with drips still falling from the engine bay.

But don’t worry. Chances are, it doesn’t mean the radiator has sprung a leak and the car is about to overheat. You can take your head out of your hands.

Rather, it’s most likely to be water dripping from the air conditioning system – and there’s absolutely nothing to worry about.

It is caused by the air conditioning compressor working hard in hot weather: due to thermodynamics, the unit itself can freeze over as it takes moisture out of the car.

© Provided by Motoring Research Ltd   Air con

When the car is parked and the air con unit deactivated, the ice on its surface melts: this is what causes the puddle under the car (and the hotter the weather, the bigger and more alarming-looking the puddle may be…).

RAC spokesman Pete Williams revealed the motoring organization -- which provides roadside assistance and insurance, among other automotive services -- had received lots of calls from drivers worried by pools of water under their cars.

“The advice is to check whether this is simply odorless water of if it has coolant in and a clear smell and color.

"If it’s is the former, then there should be no need to worry.”

Hopefully, that’s panic over. Meaning it’s only the sunshine that will leave you hot under the collar during this heatwave.