What to Do When the Engine Delays Shutting Off After Turning Off the Key?
2 Answers
If the engine delays shutting off after turning off the key, it is recommended to check the following: 1. Carbon deposits on various components: Especially inside the cylinder, such as whether the spark plugs have excessive carbon buildup or if the combustion chamber has too much carbon. Since the engine operates at high temperatures, the carbon deposits inside the cylinder can remain hot and ignite the air-fuel mixture even after the spark plugs are deactivated (when the ignition is turned off). 2. Throttle: Check if it is not closing properly. 3. Fuel injector: Inspect whether the fuel injector is leaking. Precautions for using a car engine are as follows: 1. Avoid driving in neutral: The engine itself has a fuel-cut function during deceleration, and driving in neutral can actually reduce fuel efficiency. 2. Pay attention to observations: If oil is found on the ground, determine whether it is due to engine oil leakage and promptly communicate with the car dealership to eliminate potential safety hazards. 3. When brake fluid is contaminated with or absorbs water: Or if impurities or sediments are found in the brake fluid, it should be replaced or carefully filtered immediately. Otherwise, it may lead to insufficient braking pressure, affecting braking performance.
When my car's engine delayed shutting off, I immediately thought of common causes. Modern vehicles, especially turbocharged models, are designed with delayed fan operation for cooling purposes, which is a normal design feature. However, if this isn't the case, it could be an electrical issue such as a stuck relay or a faulty sensor preventing the engine from stopping immediately. I suggest first observing the symptoms: Is the fan running after shutdown? If there's no fan noise, check if the dashboard lights are on to rule out the engine not shutting off completely. For a quick check: After turning off the ignition, wait for 5 minutes. If it still doesn't stop, avoid forcibly opening the hood to prevent danger. Simply inspect whether the headlight fuse in the fuse box is blown, as this can sometimes cause a false running state. Promptly visit a repair shop to diagnose the ECU wiring harness or replace a failed relay. Regular maintenance can prevent this issue, especially not overlooking battery aging which may cause abnormal operation.
