A jerking engine or car could be caused by a number of issues from a dirty air filter to a clogged catalytic converter. And if left unchecked for too long, the issue could cause major, more costly problems later on.
When your car jerks, it often feels like it’s struggling to move forward even when you press down on the accelerator pedal. Here are some common instances when a car can be jerking:-

(Car Jerking While Driving at a Constant Speed)

This can definitely be scary especially if there are other cars around you going at high speeds too. Common issues related to this include faulty fuel injectors or mass airflow sensors, or dirty filters.

(Car Jerking When Accelerating)

The most common instance of a car jerking is when accelerating from a standstill. When this happens, a car usually hesitates to move when you step on the accelerator, accompanied by either a sudden lurch forward or juddering as though your car is struggling to move. Common problems contributing to engine jerking when accelerating include a faulty throttle cable, worn spark plugs, or faulty fuel injectors.

(Car Jerking While Braking)

This is an uncommon problem, though it could still be dangerous. A car that jerks while braking can abruptly jerk to a stop or shake rapidly before stopping. If your car jerks when braking, you could have a warped brake rotor/disc or excessive debris on your brakes.

Generally, car jerking and shuddering occurs as a result of any of the listed factors below:-
(a.) worn-out or damaged spark plugs
(b.) dirty air and/or fuel filters
(c.) clogged fuel injectors
(d.) malfunctioning mass air flow sensor
(e.) blocked or damaged fuel line
(f.) clogged catalytic converters
(g.) transmission issues

While you can still drive a jerking car if the occurrences are minor or few and far between, the more frequent and stronger jerking when driving at constant speed could mean there are serious issues with your car. Jerking in your car may develop from a minor issue into a more major, costly issue. Call your Car service centre/Motor Mechanic for advice.