At what water level can a car be determined to have water ingress?

[ElenaMarie]

Here is an introduction to the water ingress levels for cars: 1. Exhaust pipe height: Safe wading depth. The pressure generated by the engine exhaust is sufficient to expel water that may backflow into the exhaust pipe. Therefore, as long as the engine is not manually turned off and the vehicle maintains a sufficiently stable power output, it can prevent water from backflowing into the exhaust pipe, allowing safe passage through water at this level. 2. Half-wheel height: May cause water ingress into the car. Modern cars have good waterproofing, and as long as they are not submerged for an extended period, water leakage is generally unlikely. 3. Air intake height: Maximum wading depth. The air intake height is the most critical indicator for a vehicle's wading capability, because once water enters the air intake, it can cause the engine to stall, and in severe cases, water can be sucked into the engine, causing permanent damage.

[LaReid]

I've been driving for many years and have encountered several rainy days or floods, which are really annoying. At what water level can you tell if the car is flooded? Basically, when the water reaches the middle of the wheels or the bottom edge of the doors, you should be cautious. For example, if the water reaches the sill plate—that metal bar below the door—it's easy for water to seep into the carpet. Once, I forgot to close the window, and the water only reached the wheels, but the carpet got soaked. This can lead to electrical shorts or moldy smells, so you need to check and dry the carpet immediately. More seriously, water can affect the braking system, so it's best to stop and check rather than forcing your way through. Regularly inspecting door seams and the chassis after rain can help prevent issues.

[SanEzra]

As someone who frequently repairs cars, I remind you to simply judge the water level: if it exceeds the wheel axle or the bottom of the chassis, water may enter the exhaust or electrical circuits. Specifically, when water submerges the exhaust pipe, the engine can suck in water, damaging its internals. The threshold area is a critical point; if water reaches there, the carpet will get wet. I remember one time while repairing a car, I found that small accumulations of water caused sensor failures. For prevention, measure water depth before wading through, don’t take risks—if the water is deeper than half the height of the wheel hub, don’t proceed. Afterwards, clean the drainage holes to avoid long-term rust. Checking for water traces in the engine oil or transmission fluid is a standard method.

[SanLaura]

I believe that when the water level reaches the height of the carpet or beneath the seats, it's a clear sign of water intrusion. I've assisted with insurance claims before, and at this water level, insurers often classify the vehicle as flood-damaged. The risks are significant—electrical systems may fail, such as the air conditioning not working. Over time, rust can develop, and there's always a lingering odor in the car. New drivers should avoid driving through standing water. If the water exceeds the door sill, stop immediately and call for assistance or perform basic self-rescue measures. Regular maintenance, including checking door seals and body drainage, can help minimize issues.