What are the reasons for car shaking, engine warning light on, and failure to start?
3 Answers
Car shaking, engine warning light on, and failure to start can be caused by the following reasons: 1. The spark plugs fail to spark or spark poorly due to prolonged lack of replacement or installation issues. 2. Damage to the ignition coil of one cylinder, causing that cylinder to malfunction. 3. Internal short circuit in the fuel pump, preventing normal supply of low-pressure fuel, leading to engine shaking or stalling. 4. Air leakage in the engine intake system, causing engine shaking and triggering the engine fault light. 5. One of the engine cylinders lacks cylinder pressure due to poor sealing of the valve or piston rings stuck by carbon deposits, resulting in engine shaking.
The car shakes, the engine warning light is on, and it won't start. When I encountered a similar situation, I checked the ignition system. The most common issues are worn-out spark plugs or faulty ignition coils, causing some cylinders to misfire, which makes the engine shake violently. The warning light coming on indicates that the ECU has detected a misfire trouble code. Sometimes, a broken fuel pump can't supply fuel, or clogged fuel injectors can't spray fuel, preventing the engine from starting. Lack of fuel can worsen the shaking. Last time I repaired my car, I used an OBD scanner to read the error code and found it was a coil issue. Sensors like the crankshaft position sensor failing can also cause the same problem. Shaking indicates incomplete combustion, which is high-risk—don't repeatedly attempt to start the engine. Get it diagnosed at a repair shop immediately, and check the spark plugs and fuel system yourself first. Regularly replacing spark plugs is an effective preventive measure.
As a seasoned driver who has driven various cars, I believe this issue often stems from the fuel system or sensors. Shaking is usually caused by a cylinder lacking fuel or misfiring, and the warning light is the ECU's alert. For example, dirty fuel injectors can cause uneven fuel spraying, or a weak fuel pump can lead to difficulty starting the engine and severe shaking. When the crankshaft sensor fails, the computer doesn't know when to ignite, worsening the shaking. I remember once during a long trip, my car behaved like this, but it returned to normal after cleaning the throttle body. Misfiring can also be due to air intake leaks or a dirty air filter. If the shaking is severe, turn off the engine and check the fuses and fuel pump relay. Don't push it; tow it for repair immediately. Regularly check fuel quality and filters.
