10 Causes Why Your Car Jerks When Accelerating at Low Speeds

Author

Javaughn Barrow

When your car jerks at low speeds, it means there is an issue either within the moving components of the vehicle or the components that make the car move. When you’re about to go for a drive, and you sit in the car and start your engine, put the car in D (drive) or first gear, and off to your journey, plenty of things are happening in the vehicle’s background. Many mechanical parts work in unison to provide you with the experience of performance and efficiency in the form of movement. If one of these mechanical components becomes faulty or broken, it can impact the way your car moves. Your journey can become unpleasant or even risk your safety. Some issues hide themselves under speed. When things move fast enough it can seem normal until you slow down.

What you will learn:

Importance of addressing car jerking issues promptly.

Car jerking issues can cause accidents and unexpected expenses. It is very important to address issues of car jerking as soon as possible. Your car has to work up to its manufacturer’s performance and efficiency at a basic level. This is tied to your safety when driving. If you may not know, next are some common causes that can cause your car to jerk at low speeds.

Common Causes of Car Jerking

1. Ignition System (Faulty Spark Plugs & Ignition Coils): 

Your engine has a combustion cycle that uses an air-fuel mixture compressed and ignited by an electric spark. The combustion resulting from the ignition is what we call the power stroke part of the combustion cycle. This happens across all of your engine’s cylinders in a specific and constant sequence. Just like a heartbeat, your engine’s beat creates mechanical power. That electric spark is supplied to the cylinder using spark plugs and ignition coils. If these parts become faulty, you can imagine how that can throw off that heartbeat, causing engine misfires and a domino effect of issues for movement. This results in engine power hesitation thus having a rough idle and jerking motion  

Storytime: My first car was a VW CC and one day I was driving home, close to my destination all of a sudden the check engine light came on. The car at the same time also had a hesitation when accelerating. Me being cautious I put my hazards on and made my way slowly and safely home. The next day I took the car into VW, and after diagnostics, it turned out that I had worn spark plugs. I was extra cautious and had all spark plugs and ignition coils changed and the check engine light went away. After that experience, I’d never had an issue with my ignition system again. This is why it’s important to have routine tune-up services to avoid situations like this. 

2. Clogged Fuel Injectors: 

Fuel injectors play a key role in the engine’s combustion cycle much like the spark plugs. The fuel injector provides the right amount of fuel for the air-fuel mixture. There is a preferred ratio of fuel to air that is required for efficient combustion. That ratio is 14.7:1. That’s 14.7 parts air to 1 part fuel. If the fuel injectors don’t supply the right amount of fuel this can throw off an efficient combustion cycle causing the engine to idle rough or jerk the car at low speeds.

3. Dirty Air Filter:

Air is another part of the air-fuel mixture that is essential for engine combustion. The quality and quantity of that air more specifically will affect the way the engine breathes. Imagine if you try to breathe through a dirty cloth. You’d start to cough and I’d doubt you’ll be able to walk straight. The same principle applies to you’re engine. The inconsistency in the air brings an inconsistency in power, which causes engine misfire that presents itself as a jerking motion when trying to accelerate. 

4. Faulty Mass Airflow Sensor: 

Your mass airflow sensor is designed to calculate the amount of air flowing into your engine’s cylinder for combustion. Once the air is calculated the car’s computer (ECU) calculates the right amount of fuel to mix for combustion. If this component malfunctions or is faulty the wrong information can be sent to the ECU. As a result, the engine may run lean or rich, causing improper combustion. Symptoms can present themselves as rough idles or jerking motions. 

5. Low Transmission Fluid/Transmission Problems: 

Your car’s transmission uses centrifugal force in the torque converter to turn its gears. Low transmission fluid can impact the effectiveness of this technique. Gears may be hard to select or take a while to shift, jolting the car now and then. Your transmission takes the mechanical power that your engine provides and transfers it to the wheels. So issues with your transmission can directly impact how your car accelerates at different speeds. 

Less Common Causes

6. Damaged Cylinders: 

Your engine’s cylinders are the heart of the engine and are predicated on being millimetrically perfect. The pistons and piston rings all fit perfectly within each cylinder. Any damage to the cylinder will affect how the pistons move inside the engine which ultimately affects engine power. All pistons are connected via the crankshaft, so one damaged cylinder could potentially affect all other pistons. Issues like blow-by and cylinder misfires can happen as a result of not having the right compression for engine combustions. The power delivery won’t be smooth and as a result, you can experience jerking motions.

7. Blocked Catalytic Converters: 

Your Catalytic Converter is the most expensive part of your exhaust system. It plays a key role in turning harmful exhaust gases into less harmful gases. Because the exhaust gases exit the engine block into the exhaust system it passes through the catalytic converter as a result. This component being blocked or clogged can create a backflow of exhaust/back pressure. This back pressure goes into the exhaust manifold where the exhaust is supposed to exit. In the engine’s combustion cycle exhaust is essential for the cycle to repeat efficiently. If the exhaust process is hampered in any way this can cause an imbalance of engine combustion resulting in engine misfires.

8. Damaged Gas Lines: 

The proper amount of fuel for the air-fuel mixture is also key in engine combustion. If you have damaged or blocked fuel lines, fuel filters, or fuel injectors, it can hamper proper fuel delivery. Improper fuel delivery can result in your engine running lean, which can result in engine misfires.  

9. Damaged Accelerator Cables: 

Throttle cables are connected to the accelerator pedal and the throttle valve the more you press in the accelerator pedal the more the throttle valves open to let in more air. More air means more power therefore you accelerate more. Cars with throttle cables depend on it’s cables being in good condition for efficient acceleration. Any damaged cables can result in a hesitation on acceleration when driving. This hesitation presents itself as a jerking motion as the engine can’t accelerate efficiently. 

10. Faulty Engine Mounts:

Engine mounts are meant to keep the installed engine level and steady. If you have a faulty engine mount you are going to notice excessive vibrations and rattling that can be akin to jerking when in motion. 

Diagnosing the Issue

Initial Checks

If you start to notice your car jerking at low speeds here are some checks to go through to fix the issue: 

• Check the air filter –  If the air filter is visibly clogged you can consider cleaning or replacing it to fix any issues.

• Use a Diagnostics tool/ OBD-2 Scan tool – Most times when you experience jerking in your car’s acceleration, the check engine light is on. Using an OBD-2 scan too or getting a free scan at any Autozone can give you context as to what’s wrong. Depending on the engine code you may be able to fix the issue DIY and save on costs.

Here is a table of possible check engine light codes that can cause your car to jerk at low speeds: 

• Professional Help –  Depending on how complex the issue is, you may want to consult professional help. Some things may require professional tools and expertise and you may be better off seeking out a mechanic to fix any complicated issues. 

Preventive Measures

Routine Maintenance: 

Being on top of your routine maintenance is one way to prevent issues like car jerking in motion. Most problems with your car shaking at low speeds are tied to either worn or faulty components. Regular tune-up services check on these areas to ensure your car runs at optimum efficiency. This type of oversight opens up opportunities to spot or stop any issues before they pop up.

FAQ’s 

Why does my car jerk when accelerating at low speeds? 

It’s important to know that when your car is operating many mechanical components work in unison that contribute to the smoothness and efficiency of movement. Your car jerking at low speeds can point to any of these areas. One of the best ways to pinpoint the issue is with an OBD-2 scanner or Professional help. Free Scans are available at Autozone. 

Can a bad fuel injector cause my car to jerk? 

Fuel injectors play a crucial part in engine combustion. If you have a faulty fuel injector, the air-fuel mixture won’t be as desired either causing the mixture to be too rich or too lean. Both scenarios can lead to cylinder misfires and can cause a hesitation in acceleration. 

Is it safe to drive a car that jerks when accelerating?

If your car hesitates or jerks when accelerating you should put your hazard lights on and safely pull over. It is not recommended to drive when your car is jerking when accelerating as it could be dangerous. Continued operation can cause even more issues.  

What should I do if my car jerks when accelerating from a stop?

• Safely pull over and check to see if your check engine light is on.

• Use an engine scan tool to figure out any underlying issues. 

• Seek professional help. 

How can I prevent my car from jerking when accelerating?

Routine maintenance and engine tune-up services are the best preventative measures for your vehicle. These services allow you to fix any issues before they happen giving you potential savings for any expensive issues.

Javaughn Barrow

Hello! My name is Javaughn Barrow, a young car enthusiast who writes all the articles for Karcandy.com. I’ve written over 50 articles about automobiles. With each article, I deepen my understanding and expertise in writing and the automotive world. Ever since childhood, I’ve always had a strong passion for cars. All types shapes and sizes were interesting to me. I’d spend most of my time after school researching cars and the more I found out about them the more exciting it was. In my teens, I created a fan page about corvettes posting content at least ten times a day! Yes, I was crazy about it. The page ended up garnering over 40k followers! After a while, I wanted more than a fan page. I wanted to express my passion differently. I wanted to create more helpful content, higher-quality content. My first car was a 2013 VW CC Sport. Learned very quickly car ownership wasn’t as expected. I spent a lot of time replacing control arms, cam position sensors, brake rotors, brake pads, etc. Walking away with more information than I knew before. As I was growing in my automotive journey I was learning about writing. Starting by writing a detailed outline about 300 words long then I would pay a professional to write a full 1000-word article and learn from them getting familiar with the process of writing. The moment I realized I could use my writing skills to express my passion for cars and help people simultaneously, I started Karcandy.com. I realized with my unique perspective coupled with my hard work discipline and work ethic I can create a space online to help bridge the gap between the complicated and simple in the automotive world. I’m motivated by the challenges and work it will take to create such a space. My work ethic is something I choose to refine and make better each day. I think it’s important to push myself and stay committed to my evolution as a human and this website is only one of the results of that.

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