How to Detect Water in the Engine?
3 Answers
The following are signs of water entering the engine: Stalling while driving: If the engine air filter element is soaked in water, causing the spark plugs to fail to ignite, the car will stall while driving. Overheating of the breather tube: In summer, it can damage lubrication, and hot air will emerge from the breather tube of the crankcase, causing the breather tube to overheat. Brake failure: If water enters the brake fluid and is vaporized under high temperatures, it can cause brake failure or even complete loss of function. If a small amount of water enters the engine, the vehicle may feel less powerful than usual. From the driver's perspective, they may intentionally press the accelerator pedal deeper to achieve the desired power with higher RPMs. This can lead to the piston seizing in the cylinder, the connecting rod bending or breaking due to the immense pressure, and in more severe cases, the broken connecting rod can puncture the engine block, resulting in serious consequences.
I've been driving for over 20 years and have encountered engine water ingress issues multiple times. The first thing after wading through water is not to start the engine—open the hood and check the air filter first. If the filter paper gets wet, water can easily enter the engine. Then inspect the oil dipstick; if the oil looks milky white, it's a sure sign of water contamination. Sometimes, you can see water droplets when pulling out the spark plugs, which is definitive proof of water ingress. While running, if you hear knocking noises or increased vibrations, shut off the engine immediately to avoid cylinder scoring and total failure. Last time after a flood, I skipped the inspection and ended up paying over 5,000 yuan for repairs. So now, I've developed the habit of driving slower in the rain, performing regular maintenance, and changing the oil to prevent issues before they arise. These little tips have saved me a lot of trouble.
As someone who frequently repairs cars, I recommend checking step by step. First, see if the vehicle has driven through puddles, then open the air filter box to check if the filter element is damp. Next, pull out the dipstick—if the oil appears milky or emulsified, it's a typical sign of water ingress. Removing the spark plugs to inspect the threads for water marks is also effective; if the spark plugs are wet, water may have entered the combustion chamber. When turning the key to start, listen carefully within the first half-second—a metallic knocking sound indicates that the connecting rod has been bent by water. Never force-start the engine, or it will be ruined. It's best to have a professional use tools to measure cylinder pressure to avoid unnecessary damage.
