What to Do When the Engine RPM Fails to Increase After Driving Through Water?
2 Answers
If the engine RPM fails to increase after driving through water, take the vehicle to a repair shop for inspection. When the engine warning light is on: First, perform a self-check. If it is safe, check the dashboard for any faults. If you cannot confirm whether the vehicle can continue to operate, ensure your safety and contact a technician from the 4S store or consult a mechanic at the repair shop. Reasons for the warning light: When there is an abnormality in related system components, the engine control unit (ECU) stores a fault code and directly sends a signal to illuminate the warning light on the dashboard.
I often deal with such water wading issues. Usually, when the RPM can't increase, it's because the engine has taken in water. Water entering the intake or cylinders prevents normal air intake, making the engine 'gasp for breath,' hence the RPM won't rise. The first thing to do is avoid forcing ignition or acceleration, as this could seize the engine. First, tow the car to a safe place and check if the air filter is soaked. If it is, replace it, and ideally let the car air dry for a few hours. Then inspect the spark plugs for water marks, cleaning them if necessary. After that, try idling a few times to see if the RPM returns to normal. If it still doesn't work, call a mechanic immediately. Wading through water can also damage sensors; for example, the throttle position sensor can malfunction if it gets wet. It's advisable to assess the depth before crossing deep water, avoid rushing through, and afterward, check the chassis and electrical wiring to prevent rust and short circuits. In short, safety first—don't push your luck.
