When a car is found to be shaking while driving, it is typically due to tire-related faults. Common causes include tire misalignment, ineffective tire balancing, or loss of balancing weights from the tire. Moreover, if the vehicle has previously had its rims deformed from an external force or had chassis collisions, shaking might also occur while driving.
Engine carbon deposits are among the most common reasons for car vibrations. Among all components that might develop carbon deposits, the throttle body and fuel injectors are the most susceptible. When the vehicle starts to shake, one should first check the throttle body and fuel injectors. If the throttle body is found to be excessively dirty or the fuel injectors have significant carbon buildup, it is advisable to clean them promptly using injector and throttle body cleaners.
The engine mount, also referred to as the engine foot, is the engine's shock absorption system. It's responsible for absorbing the minute vibrations when the engine is running. If there's an issue with the engine mount, these vibrations can be transferred to the steering wheel and into the cabin, resulting in a shake during idling. Activating the vehicle's electrical system can easily induce shaking. The engine will take on added load when electrical systems are activated, leading to a drop in idle speed.
To compensate for the shaking caused by the drop in idle speed, the engine will automatically raise its RPM. Hence, when activating car electrical systems, especially turning on air conditioning during summer, engine shaking might frequently occur. If the shake during idling doesn't decrease when the car's air conditioning compressor is operating, it's likely due to the aging of the engine mount, necessitating its replacement.
If the engine carbon deposits have been cleaned, the throttle body has been washed, oil pads and spark plugs have been replaced, and the vehicle still shakes at idle, it's recommended to visit a 4S shop or a repair shop. They will check if the fuel supply pressure and intake pressure sensors are working properly. An abnormal fuel pump supply pressure or inaccurate and poor-performing intake pressure sensors can also cause the vehicle to shake.
