What Causes Engine Shaking and Lack of Power After Driving Through Water?

[RonanRose]

After driving through standing water, the car shakes and lacks power because a small amount of water enters the high-voltage wires during wading, causing poor ignition and the spark plugs' high voltage to supply the engine block. If possible, it is recommended to use an air compressor to remove and dry the high-voltage wires, or to use the engine's heat to evaporate the moisture. Additionally, it is advisable to dry all electrical wire connections and blow out the air filter. Common causes and solutions for car shaking: 1. Dirty Air Filter: The air filter is designed to protect the engine and reduce wear, typically requiring replacement every 10,000 kilometers. If not replaced in time, insufficient air intake can cause low idle speed, leading to engine shaking. Simply replacing the filter can resolve this issue. 2. Broken High-Voltage Wire: A broken high-voltage wire refers to a break in the wire core, which can affect ignition and cause engine shaking. Use a multimeter to measure resistance and replace the wire with significantly higher resistance. 3. Spark Plug Lifespan: After 30,000-40,000 kilometers, the ignition efficiency noticeably decreases, affecting ignition. This is the most common issue, and replacing all spark plugs can solve it. 4. Low Idle Speed: The engine's idle speed is preset in the computer. When the RPM drops below a certain range, the car's computer automatically adjusts. If the idle speed is too low and causes shaking, it indicates it's beyond the computer's control. Some cars have an adjustment screw on the throttle body to regulate idle speed, while others do not. For the latter, check the idle valve, throttle body, air flow meter, vacuum sensor, and adjust ignition timing (for cars with distributors) to increase idle speed. Low coolant temperature can also cause low idle speed, so check and replace the thermostat if necessary. 5. Abnormal Coolant Temperature: The engine operates within a normal temperature range. High coolant temperature can cause early ignition timing, altered air-fuel mixture, thinning of oil viscosity, and reduced lubrication. Common causes include low coolant level, faulty thermostat, non-functioning fan, or inaccurate temperature switch. Resolving these issues can eliminate the shaking. 6. Clogged Fuel Injectors: Fuel injectors in electronic fuel injection cars are critical components with a long lifespan, often reaching hundreds of thousands of kilometers. However, deposits in gasoline can clog the injector nozzles, causing uneven fuel delivery and inconsistent cylinder operation, leading to engine shaking. The solution is to remove and clean the injectors. 7. Carbon and Oil Deposits: Over time, carbon and oil deposits can clog the throttle body, idle valve, and intake ports, restricting airflow and causing unstable idle speed and shaking. Inspect and clean these areas with a cleaning agent without disassembly to resolve the issue.