What Causes the Engine Fault Light to Illuminate and the Car to Shake?
2 Answers
The reasons for the engine fault light illuminating and the car shaking are: 1. Internal short circuit in the fuel pump, preventing normal supply of low-pressure fuel; 2. Air leakage in the engine intake system; 3. Excessively dirty throttle or excessive carbon buildup in the fuel injectors; 4. Aging of engine components; 5. Poor combustion of the air-fuel mixture in the engine; 6. Poor quality or substandard fuel; 7. Malfunction in the working condition of spark plugs, high-voltage wires, or ignition coils. The solutions for the engine fault light illuminating and the car shaking are: 1. Check the working condition of spark plugs, high-voltage wires, and ignition coils; 2. Clean engine carbon deposits, throttle, replace oil pads and spark plugs; 3. Visit a 4S shop to check the fuel supply pressure and whether the intake pressure sensor is functioning normally.
Last month, my old Passat also had the engine light on and was shaking like a sieve, which scared me so much that I immediately pulled over. The mechanic checked it and said one of the ignition coils had failed, causing the fourth cylinder to stop working completely. He said this situation is particularly common—either the ignition coil is bad or the spark plugs have reached the end of their lifespan. Another time, my friend’s car had the same issue last month after refueling, shaking so badly that the steering wheel was hard to hold. The inspection revealed that it was due to clogged fuel injectors from using low-quality gasoline. Also, if the mass airflow sensor fails or there’s a vacuum leak, the light can come on and the car may shake. The mechanic specifically reminded me about this when cleaning the throttle body last time. If you encounter this situation, it’s best not to force the car to keep running. Pull over safely and call for assistance to avoid damaging the catalytic converter.
