It can be frustrating and disconcerting if your car jerks when rushing to work or a business meeting. This can happen for several reasons, and it is crucial to diagnose the vehicle and fix the leading cause as soon as possible.
Auto manufacturers have advanced their technologies, making cars more complex. So, one symptom can have different possible causes. For example, car jerks when driving on a highway can be caused by several system malfunctions. In this article, I’ll explain why car jerks when accelerating, the best solutions, and the cost of fixing the problem.
What are the possible causes of Car jerks when accelerating
There are several reasons why your car jerks when accelerating. But the most common reasons for car jerks when accelerating are faulty mass airflow sensors, clogged catalytic converter, broken spark plugs, damaged fuel pumps, dirty fuel injectors, dirty fuel filters, or accumulation of moisture in the system.
Let’s look at these probable causes one after the other for a better understanding.
Dirty fuel injector
A dirty fuel injector is the most common reason a car jerks when accelerating. It can also pose several system issues, like engine misfires and rough idling. The vehicle can also stutter due to inconsistent fuel injection into the engine.
It’s normal for fuel injectors to get dirty over time. That’s why it is crucial to add fuel injector cleaner every time you visit the gas station. The injector cleaner will clean up any dirt in the fuel delivery system.
Dirty air filters
The air filter is responsible for filtering the air that goes into the engine. Over time, the pollutants the filter prevents from entering the engine will clog it. If the air filter becomes dirty, it won’t allow adequate airflow into the engine, especially when accelerating. As a result, the engine will jerk when accelerating.
Clogged catalytic converter
The primary function of the catalytic converter is to convert harmful exhaust gas into less toxic gases before releasing them into the atmosphere. If there’s a rich air-fuel mixture in the engine, the unburnt fuel in the exhaust gas can damage the catalytic converter. If the catalytic converter is damaged, it’ll cause the car to stutter as you depress the gas pedal.
So, if you are asking, why is my car stuttering when I accelerate? It could be you have a clogged catalytic converter. Other signs of a damaged catalytic converter include jerking, bad gas mileage, a rotten egg smell, and a check engine light on the dashboard.
Clogged mass airflow sensor
If a car jerks when accelerating at low speeds on automatic or manual transmission, you likely have a clogged mass airflow sensor. The mass airflow sensor is responsible for measuring the amount of air that enters the engine and relates this information to the powertrain control module.
The powertrain control module then uses the information to instruct the fuel injectors on the amount of fuel to send into the system. This helps for proper air-fuel mixture into the engine. If the mass airflow is faulty, it will cause jerking, surging, rough idling, and engine misfiring.
Worn-out spark plugs
One of the most common causes of engine misfires and jerking is worn-out spark plugs. It is also the easiest to diagnose and resolve. Spark plugs are designed to ignite the air-fuel mixture in the combustion chamber. Worn-out spark plugs will not properly burn the air-fuel mixture, causing jerking, rough idling, and engine misfiring.
Moisture buildup
If you have one of these old cars with a distributor, there could be a moisture buildup in the distributor cap. In cold weather conditions, condensation forms in the distributor cap, especially when you park your car outside overnight. This will cause the vehicle to jerk when accelerating from a stopping point.
Fortunately, the jerking will clear once the condensation clears off. However, repeated moisture buildup in the distributor cap can stress the engine.
Lousy fuel filter or pump
Fuel delivery issues are common causes of engine misfiring, stuttering, loss of power, and jerking. If the fuel delivery is compromised, it’ll affect the air-fuel ratio in the combustion chamber. It could be either a bad fuel pump or a clogged fuel filter.
If your car jerks when accelerating and no check engine light, you have a bad fuel pump or filter. If the pump is the root cause, the problem will only occur when the car is hot. The car will run smoothly once the engine cools down. But if the vehicle jerks every time you accelerate, whether the engine is hot or not, it is the fuel filter.
Clogged fuel lines
If your car jerks when releasing accelerator or pressing the gas pedal, it could mean you have blockages in the fuel lines preventing adequate fuel delivery into the engine. The fuel pump transports fuel to the engine through the gas lines.
If the line is clogged or damaged, it’ll affect the fuel pressure sent to the engine. And if the engine doesn’t receive the required fuel, it’ll cause it to jerk. A leaking fuel line can even lead to a fire outbreak while driving.
Low transmission fluid
Low transmission fluid can cause system issues like transmission slippage, overheating, and jerking when accelerating. Lurching, jumping, and jerking on acceleration are other common effects of low transmission fluids. You have to ensure you regularly check the transmission fluid and keep it at the appropriate level.
Worn-out throttle cable
While modern vehicles on the road today use electronically controlled throttle bodies, some still have throttle cables. The throttle cable, also known as the accelerator cable, is the link that connects the gas pedal to the throttle plate.
If the cable wears out over time, it’ll cause the vehicle to jerk or lurch instead of providing a smooth driving experience as you depress the accelerator. Thankfully, this problem is easy to identify. If the cable is worn-out, you’ll see the damage on it.
Clogged air filter
Air and fuel work hand in hand for optimal combustion. If you noticed, I have repeatedly said the air-fuel should be at the proper ratio. The air filter filters the air that goes into the engine. Over time, these filtrations will clog the filter, making it unable to deliver the required amount of air into the engine.
If there is restricted airflow to the engine, it’ll cause the car to stall, stutter, or jerk when accelerating. Aside from getting clogged, a dirty air filter can allow dirt into the engine, causing the engine to jerk or misfire.
Malfunctioning transmission control module (TCM)
If you notice your automatic transmission vehicle stalls, stutters, or jerks only when changing gears, you have a malfunctioning TCM. The transmission control module (TCM) is responsible for changing gears as you accelerate your car. If it fails, gear changes will be unpredictable or delayed.
How do you fix your car if it jerks when accelerating?
Here are the best possible solutions if you are wondering how do you fix a car jerking when accelerating.
Tune-ups
The best solution to prevent car jerking when accelerating is to run routine tune-ups. This way, the vehicle will not jerk when accelerating. And if the car eventually starts jerking, your next regular tune-up will rectify the issues.
Car tune-ups include:
- Checking and replacing defective ignition coils.
- Replacing lousy spark plugs.
- Cleaning air and fuel filters.
- Inspecting other essential system components like the car sensors.
Routine maintenance will help you identify and address issues at the earlier stage.
Using fuel injector cleaners
Don’t be penny wise, pound foolish. Get a bottle of fuel injector cleaners every time you visit the gas station or, at most, after covering a few thousand miles. This helps prevent any deposits on the fuel delivery systems and ensures the engine receives the right amount of air-fuel mixture for a seamless operation.
Catalytic converter
As I explained earlier, clogged catalytic converters are one of the primary reasons a car jerks when accelerating. Luckily, you can unclog the catalytic converters without removing them. You just need the right fuel system or catalytic converter cleaner to unclog the catalytic converter.
Contact a mechanic
If you’re not a DIYer or you are unable to diagnose and address the underlying problem, contact your mechanic. Trained mechanics have the tools and expertise needed to resolve the issue.
How much does it cost to car jerking when accelerating?
The repair approach, your car make and model, and the mechanic fixing the problem greatly influences the cost of fixing a car that jerks when accelerating. However, you can pay as low as $30 to $150 if you have a dirty air filter or as high as $300 to $1700 if you need to replace the catalytic converter.
Final words
You have seen why car jerks when accelerating. It can be an unnerving situation you don’t want to experience, especially when overtaking a vehicle on the highway. And the repair cost can be expensive. But here’s the good news, a routine tune-up could be all you need to prevent or fix the problem. During regular tune-ups, the mechanic services most of the parts that could be the cause of the jerking.
