Can You Start the Engine If Water Enters the Exhaust Pipe While Parked?

[Hudson]

You cannot start the engine if water enters the exhaust pipe while parked. If the water ingress is not severe, you should check the electronic systems and remove the water from the engine to prevent impurities in the water from clogging the three-way catalytic converter or damaging the oxygen sensor, which could lead to engine water damage. The exhaust pipe is a device designed to reduce vibration and noise while extending the lifespan of the exhaust muffler system. Installed between the engine exhaust manifold and the muffler, the exhaust pipe provides flexible connectivity for the entire exhaust system. Its structure consists of a double-layer corrugated pipe covered with a steel wire mesh sleeve, with clamping rings at both ends. To enhance noise reduction, the corrugated pipe may include an expansion joint or mesh sleeve inside.

[VonRiley]

Bro, I had the same issue last year when my car was parked in a pothole during heavy rain, and the exhaust pipe got flooded. I almost instinctively turned the ignition, but luckily a friend stopped me, explaining that water could get sucked into the cylinders, blocking them and preventing the pistons from moving, which could total the engine. Later, it was towed to the repair shop, and the mechanic spent half a day draining the water to fix it. Since then, I’ve learned to always check if the exhaust pipe is dry after driving through water. If it’s flooded, never start the engine—wait patiently for the water to drain or call a professional. Safety first—don’t cut corners and damage your car. Prevention saves money and hassle. When parking in the rain, always choose higher ground.

[VanLily]

After thirty years of driving, the lesson I've learned is never start the engine if water enters the exhaust pipe while parked. Otherwise, water can rush into the engine, seize the pistons, and damage internal components, leading to costly repairs. I've handled similar situations multiple times and always remind beginners to wait for natural drainage or gently press the accelerator (but never start the engine). Before driving through water, plan your route carefully and inspect after rain. If water does get in, stop immediately and have it towed for repairs. Engine protection starts with attention to detail—patience is safer than impulsiveness, and prolonging your car's lifespan is the real way to save money.

[CollinMarie]

In principle, if water enters the exhaust pipe and the engine is started, water can be sucked into the cylinders during intake. Since water is incompressible, the piston may be blocked, leading to hydraulic lock, which can cause connecting rod bending or severe engine damage. Therefore, it is crucial not to risk starting the engine. After driving through water, always check the water situation before taking action. Prevention is always better than cure.