Why is there water leaking under the car?
2 Answers
Reasons for water dripping under the car: 1. If it occurs after the air conditioning has been running for a while, this is a normal phenomenon. When the air conditioning is operating, moisture in the cabin condenses on the evaporator to form water droplets, which are then discharged outside the vehicle through the drain pan and drain pipe. 2. Check if the antifreeze in the radiator is low. If it is, promptly visit a 4S shop to inspect the cooling system for faults. 3. Water dripping from the muffler and exhaust pipe at the rear of the car is also normal, commonly observed during winter. 4. When gasoline is injected into the cylinder and mixed with air, it undergoes complete combustion in the combustion chamber, primarily producing carbon dioxide and water. The water, in the form of vapor at high temperatures, is expelled into the atmosphere.
I remember back then I had just replaced my old car and drove it quite often. One time after parking, I noticed a large puddle of water under the car, which scared me into thinking the engine was broken. Later, a mechanic friend explained that it was most likely condensation water from the air conditioning system. Especially in summer when the AC is on, humid air inside the car condenses into water droplets when it meets the cold pipes, which then drains out through the drainage tube to the underside of the car. This water is transparent and odorless, completely normal. However, he said if the water is green or red, it might be coolant leakage, indicating a problem with the cooling system, such as a cracked radiator or a faulty water pump. Another time, after washing the car on a rainy day, there was some leakage, and my friend said it was just residual rainwater, nothing to worry about. The key is to identify the location and nature of the water: AC water is usually under the center of the car, while engine leaks are likely at the front. Timely checks can prevent major repairs. In short, don’t panic right away—normal drainage is common, but unusual colors mean you should get it fixed quickly.
