Is It Normal for Water to Leak Under the Car When the Air Conditioning Is On in a New Car?
2 Answers
It is normal for water to leak under a new car when the air conditioning is on because the air conditioning system is designed with a drainage function. When the car's air conditioning is turned on, the surface of the evaporator coil forms a cold surface, causing the water vapor in the air inside the car to condense into water upon contact with the evaporator coil. The condensed water then drains out of the car through a drainage pipe, with the drainage hole located right under the chassis. Note that when the car's air conditioning is on, it is normal for water to drip under the car. However, if the condensed water leaks inside the car, it is abnormal. The common location for such leaks is the passenger side, usually caused by aging air conditioning pipes that may become loose or cracked over time. This issue can be resolved by reinstalling or replacing the pipes. Water may also drip from the muffler or exhaust pipe at the rear of the car, which is also normal. However, this dripping usually occurs in winter. The reason is that the gasoline mixed with air in the cylinders burns completely, producing carbon dioxide and gaseous water vapor. Due to the rear position of the muffler and exhaust pipe, when the water vapor encounters colder temperatures, it condenses into liquid water and is expelled with the exhaust flow.
I had only been driving this new car for a few days when I first noticed water dripping under the car in the parking lot, which made me nervous. I quickly took a photo and asked my mechanic friend about it. He explained that this is a normal phenomenon when the air conditioning is working—the AC system condenses moisture into water droplets while cooling the air and drains it outside through a pipe. The amount of water depends on the humidity of the weather, and it’s more noticeable during rainy summers. As long as the liquid is clear without oil stains or strange odors, there’s no issue. The new car is well-designed, and the drainage hole is usually located in the middle of the chassis, so you can easily check for abnormalities yourself. Just pay attention to whether puddles on the ground are near the AC area during regular use, and remind technicians to clean the filter during routine maintenance to prevent pipe blockages or leaks. Only large amounts of water or colored liquids should be a cause for concern. New car owners should relax and not over-worry.
