Why is there water on the floor of the Jetta cabin?
2 Answers
If it hasn't rained or the car hasn't been washed, but there is water in the cabin, first check if there is any leakage in the air conditioning pipes. Also, when the engine is cold, check if the coolant in the radiator has decreased. Water ingress in vehicles can be divided into two situations: Water ingress while driving: For ordinary sedans, when the water level reaches 20 cm (for SUVs with higher ground clearance, this threshold increases to 30 cm), there is a risk of water entering the engine. Because the intake pipe of the engine is positioned low, water can be sucked into the engine during wading. Similarly, the exhaust pipe outlet, being below the waterline, can also draw water into the engine during wading. Water ingress while parked: If the vehicle is parked in a low-lying area with poor drainage, it may get submerged during heavy rain. When this happens, external water can enter the cabin through door gaps, the air conditioning external circulation channels, and other crevices. Typically, this results in the carpet below the seats getting soaked. If the external water level is high, even the battery and some electrical components may be at risk of water damage. Solutions: When wading is unavoidable, shift to a low gear and proceed slowly. During rainy days, park your vehicle in a higher location. If water ingress occurs, have the car towed to a repair shop for inspection.
I remember encountering this issue when I drove my Jetta. It was probably caused by a clogged sunroof drain hole or a leaking air conditioning condensate pipe. After the rainy season, there was a pool of water on the car floor. I thought it was a minor issue, but the water had seeped under the floor padding, making the interior damp and moldy. Later, I found leaves blocking the sunroof drain. A simple check method: use a soft hose to flush the sunroof drain channel or locate the A/C drain pipe under the car to see if it’s clogged. If it’s serious, get it fixed immediately to prevent floor rust and frame corrosion. I used dry towels to soak up the water and sprayed some disinfectant, but long-term, regular cleaning of the drains is necessary. Safety first—water damage to electrical circuits could cause a short circuit, which is even worse.
