Does the BMW 730 have protection against stalling due to water ingress?

[VanAniyah]

BMW 730 does not have an automatic protection function after stalling due to water ingress. Hazards of water ingress in cars: After water ingress, the exhaust pipe may become blocked, preventing the car from functioning properly. The inability to expel exhaust can affect the cylinder compression ratio, increasing fuel consumption. Additionally, water mixing with engine oil can dilute the oil, leading to insufficient lubrication and an excessively high oil pan fluid level. How to handle stalling due to water ingress: After the car stalls due to water ingress, do not attempt to start the engine. Water in the engine cylinders can contain impurities, and restarting the engine may cause cylinder scoring. If you discover water in the engine, do not drive the car to the repair shop yourself. Instead, contact a towing service to transport the vehicle.

[Ricardo]

That day I was driving in heavy rain and encountered waterlogged roads, and my 730 just stalled. Fortunately, the automatic protection system kicked in. BMW's high-end models will actively cut off fuel supply and ignition when encountering water ingress to prevent the engine from continuing to operate and causing cylinder scoring. But this doesn't mean you can let your guard down—water has already entered the engine interior, the piston connecting rods may be deformed, and the valves will also suffer. So the protection is just the first step to minimize losses; you must call a tow truck immediately and never attempt a second ignition. Last time I had it towed to the dealership, disassembling the engine for cleaning and replacing parts cost me tens of thousands—it really hurt. During the rainy season, it's better to avoid puddles when driving; luxury cars cost much more to repair than ordinary cars.

[ColinAnn]

Last week at the auto repair shop, I encountered a BMW 7 Series owner whose car stalled after plowing through a flooded area during heavy rain. He said the vehicle shook violently before stopping—that's BMW's engine protection system kicking in. The system detects water ingress into cylinders and cuts off fuel and power supply within 0.5 seconds to prevent catastrophic hydro-lock damage. Don't expect this to keep the engine unscathed though, as connecting rods and pistons can still bend. This electronic protection acts like an 'emergency brake', but a complete teardown overhaul is still required afterward. When towing, always remember to shift to Neutral and engage the parking brake. If you foolishly attempt to restart the engine, expect repair bills to triple at minimum.

[LeElla]

During the rainy season, we often encounter cases of BMWs stalling after wading through water. Models like the 7 Series indeed have automatic protection. The moment the system detects water entering the cylinders, the onboard computer will forcibly cut off the engine and fuel supply—much faster than human reaction. But honestly, this protection is like an airbag: it can save your life in a crash, but the vehicle damage remains severe. Water would have already entered the crankcase, damaging bearings and piston rings. Once towed to the repair shop, diagnostics will likely reveal the need to replace internal engine components. BMW dealerships charge exorbitant fees for such water-damaged vehicles—replacing a set of connecting rods alone costs tens of thousands. The key is not to restart the engine, or the protection mechanism would be in vain.