What are the effects of water entering the car cabin?

[AveryLynn]

If too much water enters, it can affect the heart of the car—the engine, transmission, belts, and other components. 1. Minor water ingress: If the amount of water entering the cabin is very small and the affected area is minimal, you can wipe the water stains clean yourself, lower the windows, and, if possible, open all the doors to dry the car in the sunlight. Additionally, placing some desiccants inside the car can help. 2. Removing musty odors: If the water ingress is severe or the car still has lingering musty odors after drying, it means water has seeped beneath the floor mats, including into materials like foam, causing dampness and mold. In such cases, it’s necessary to visit a professional auto repair shop to remove the seats and floor mats for thorough cleaning to eliminate the musty smell.

[Stewart]

I know all too well about water getting into the cabin. Last time after a heavy rain, there was 5cm of standing water in my car. I thought just drying it would be enough, but the problems were serious. The wiring under the seats short-circuited, frying the window regulators. When the mechanic pulled up the carpet, we found all the soundproofing foam had mold growing - that musty smell lingered for six months. Worse yet, the steering column under the wheel rusted, making awful creaking noises when turning, and ultimately cost over 2,000 yuan to replace. The most dangerous part was when the brake pedal sensor failed, nearly causing a rear-end collision. Now I'm hyper-vigilant about sunroof drain holes - I clear them myself every car wash. If water gets in, I immediately take it to a professional shop to remove seats for proper drying, because post-water damage repairs can end up costing more than a new car.

[DeLeila]

Last month, the door seals on my old car aged and started leaking. I didn’t take it seriously at first, but three days later, the interior turned into a mold breeding ground. My kid in the back seat kept coughing and had allergies—the doctor said it was due to mold spores causing respiratory issues. When we removed the seats, we found the foam soaked and blackened, with mildew all over the leather seat stitching. The car wash quoted over a thousand for a deep clean, with no guarantee of complete sterilization. What’s worse, every time I open the car door during the rainy season, there’s a musty smell, especially noticeable when the AC is on. Now, I have to keep the sunroof open all day for ventilation. My advice: if water gets in, dismantle and dry the interior immediately—health risks from mold are worse than car damage, especially for families with elderly or young children.

[DeJulian]

With over a decade of experience repairing hundreds of flood-damaged vehicles, I've seen numerous lingering issues from water intrusion into the cabin. Corroded wiring connectors often cause power window failures, while short circuits in door lock control modules are common occurrences. In severe cases, the entire instrument cluster may go black. Waterlogged ABS sensors on the chassis lose accuracy, potentially increasing braking distance by 2-3 meters. Mechanically, the most concerning issue is rust-induced stiffness in water-damaged steering gears - especially dangerous at highway speeds. When floor panels rust through, you'll hear alarming creaks over speed bumps. The real problem is that flood cars' electronic issues act like time bombs - faults may emerge six months later, and these vehicles depreciate 30% more than accident-damaged cars at resale.