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 a Jerking Car Feels Like
Your car can jerk in a number of situations be it while driving or at a standstill. 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
Imagine driving while maintaining speed on the highway and your car engine suddenly jerks.
It usually involves your car juddering abruptly before continuing like normal, or, in some cases even hesitating for a second and then lunging forward when you step on the accelerator.
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 Idling
Sometimes, your car could jerk, shake, or rattle even at idle. Slight vibrations are normal, especially in an older car but excessive vibrations could be a sign of structural issues like worn-out bushings or damaged engine mounts.
Though not as common, you could also have your engine jerking or stuttering while idling, and feeling like it’s out of breath. If your car jerks like this at a low RPM, you could have bad spark plugs or a worn throttle sensor.
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.
Your car might also have reduced stopping power which can lead to accidents especially if you’re in a situation where you can’t brake in time. If your car jerks when braking, you could have a warped brake rotor/disc or excessive debris on your brakes.
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.
#1. 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.
#2. 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.
#3. 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.
#4. 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.
#5. 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.
#6. 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.
#7. 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.
#8. 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.
#9. 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.
#10. 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.
#11. 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.
#12. 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.
Things You SHOULD NOT Do if your Car Jerk
If you’re experiencing a car jerk while accelerating, it’s important to rule out some potential causes. Here are 6 things you SHOULD NOT do if you’re having this problem.
1. Don’t ignore the problem: If your car is jerking while accelerating, it’s important to get it checked out as soon as possible. Ignoring the problem could lead to more serious issues down the road.
2. Don’t try to fix the problem yourself: Unless you’re a trained mechanic, it’s best to leave car repairs to the professionals. Trying to fix the problem yourself could make things worse.
3. Don’t keep driving if the car is jerking severely: If the jerk is severe, it’s best to pull over and turn off the engine until you can get the car towed or repaired.
4. Don’t get into a car with someone driving erratically: If you’re riding with someone who is jerking their car back and forth, refusing to stop, or driving dangerously, don’t get in the car with them.
If you must get in the car with someone driving erratically, try to get them to stop.
5. Don’t let your children ride in a car if a friend or relative is driving erratically: Getting your children out of the car may be hard if danger arises, but you can try. If the driver is jerking the car back and forth or driving in a way that seems dangerous, tell your child to jump out of the car and run away.
6. If your car is jerking, you should not race the engine: If you are driving and your car starts to jerk, don’t panic. Don’t race the engine because this won’t make it stop. Slow down, pull over and get out of the car as quickly as possible.
Step-by-Step Guide to Diagnosing the Problem
- Check for Error Codes
- Use an OBD-II scanner to read any error codes from your car’s computer. These codes can provide specific clues about which component is malfunctioning.
- Inspect the Fuel System
- Look for signs of clogged fuel injectors or a faulty fuel pump. Listen for unusual noises from the fuel pump and check fuel pressure if possible.
- Examine the Spark Plugs and Ignition System
- Remove and inspect spark plugs for wear and tear. Replace them if they appear dirty or worn. Also, check the ignition coils for any signs of damage.
- Evaluate the Air Intake System
- Check the air filter for dirt and debris. Replace it if it’s clogged. Inspect the mass air flow sensor and clean or replace it if necessary.
- Test the Transmission
- If you suspect transmission issues, check the fluid levels and look for signs of contamination. Consider whether the transmission fluid needs to be changed or if there are any mechanical issues.
- Inspect the Exhaust System
- Examine the catalytic converter for blockages. A clogged catalytic converter can cause jerking and should be cleaned or replaced if necessary.
- Check for Vacuum Leaks
- Listen for hissing sounds which can indicate a vacuum leak. Use a smoke machine or spray carb cleaner around suspected areas to find leaks.
Tools and Methods for Effective Diagnosis
- OBD-II Scanner: Essential for reading diagnostic trouble codes (DTCs).
- Fuel Pressure Gauge: Helps in checking the fuel system pressure.
- Spark Plug Socket and Gap Tool: Necessary for inspecting and replacing spark plugs.
- Multimeter: Useful for testing electrical components like ignition coils and sensors.
- Vacuum Gauge or Smoke Machine: Aids in identifying vacuum leaks.
- Manuals and Repair Guides: Reference materials for specific diagnostic procedures.
How do you fix your car if it jerks when accelerating?
In some cases, it’s not difficult to resolve the jerking problem. You need to read the trouble codes to find out what’s wrong and perform maintenance.
This may require changing the spark plugs, air filter and ignition coils. Otherwise, check the fuel pressure and MAF sensor or contact a professional.
#1. Read Trouble Codes.
Your first step is to connect a compatible code scanner to the OBDII port to read any DTCs. If the Check Engine Light is on, a trouble code (or multiple) has been set that can help you figure out what’s wrong.
In some cases, the code may lead you right to the issue, while other times, it can be generic. For example, if you get the P0172 – System Too Rich (Bank 1) code, you may not have any idea what could be causing it.
That’s why we’ve put together a free online trouble code library to help with your research. We take the guesswork out of deciphering these confusing codes.
#2. Check Spark Plugs And Ignition Coils.
If you haven’t performed maintenance in a while, it might be time to replace the spark plugs or ignition coils. Take a look at the plugs to see if the gap looks too wide or if there’s carbon buildup on the tips. If so, it’s best to replace them and most don’t cost that much.
You can also use a spark tester to check the ignition coils. If one is defective, you can replace it singly. There’s normally no reason to replace them all at the same time unless they are very old and you are worried about the others failing.
#3. Check Fuel Pressure.
Your next step is to check the fuel pressure and system. If the pressure is off, you must determine what’s causing it. In some cases, a simple fuel filter replacement is all that’s needed. Otherwise, you may need a new fuel pump.
There’s also the chance that the injectors are clogged or defective. It’s normally worth trying a fuel injector additive first to see if that resolves the situation.
#4. Clean the MAF Sensor And Check the Air Filter.
If maintenance has been neglected, your next step is to check the air filter. Maybe it’s just clogged and needs to be replaced.
Otherwise, you want to move on to the MAF sensor. Sometimes, the sensor simply becomes contaminated and needs to be cleaned. Here are some steps to consider.
- Let the engine cool.
- Unplug and remove the sensor. Find the location in your factory service manual.
- Put the sensor on a clean towel.
- Spray MAF sensor cleaner on the part.
- Carefully clean the housing, connectors, terminals and all sides of the sensor.
- Once the sensor is completely dry, reattach it.
If cleaning the sensor doesn’t change the performance of the vehicle, you may need to replace it.
#5. Contact A Professional.
There’s no shame in admitting that you aren’t sure what to do next. If you’ve exhausted all of the steps you feel comfortable performing, it’s time to reach out to a trusted mechanic in your area.
Do your research if you aren’t sure where to go. It’s helpful to listen to friends and family for recommendations, but you should also check online reviews too.
When to Seek Professional Help
You should seek professional help when your car’s persistent jerking and acceleration issues indicate deeper engine or transmission problems. Ignoring these signs not only compromises your driving safety but also risks severe damage to your vehicle.
Here are the key signs that it’s time to consult a professional:
- Frequent Car Jerks: If your car jerks more often, it’s a clear signal.
- Consistent Lack of Acceleration: Struggling to speed up is a serious concern.
- Unusual Noises During Operation: Any strange sounds from the engine or transmission.
- Error Messages on Dashboard: Pay attention to warning lights or messages.
Obtaining expert diagnosis for your car’s jerking and acceleration issues guarantees precise identification and successful resolution of underlying problems.
When you’re part of a community that values reliable, well-maintained vehicles, it’s essential to recognize when to step aside and let a professional mechanic take the wheel.
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.
Preventive Measures: Tips to Prevent Your Car From Jerking When Accelerating
While some causes of a jerking car during acceleration may be unavoidable, there are several preventive measures you can take to minimize the likelihood of encountering this issue:
Regular Maintenance
Adhering to the recommended maintenance schedule for your vehicle is crucial. Regular oil changes, filter replacements, and fluid level checks can help prevent many potential issues that could lead to jerking during acceleration.
Timely Repairs
If you notice any strange noises, vibrations, or performance problems, make sure to deal with them right away. Ignoring these warning signs can lead to more severe problems, including a jerking sensation during acceleration.
Careful Driving Habits
Avoid aggressive acceleration and sudden throttle inputs, as these can put excessive strain on the engine, transmission, and other components, potentially leading to premature wear and jerking issues.
Use Recommended Fluids and Parts
Always use the manufacturer-recommended fluids and genuine replacement parts for your vehicle. Using inferior or incompatible components can lead to various issues, including jerking during acceleration.
By following these preventive measures, you can keep your car running smoothly and reduce the chances of experiencing jerking during acceleration, ensuring a safer and more comfortable drive.
FAQs.
Q: Why is my car jerking when I press the gas?
The most frequent cause of a car jerking while accelerating is that one or more spark plugs may be failing. If the issue persists, performance will be reduced. Have a professional check them and replace them if necessary if you suspect this may be the case.
Q: What does car jerking mean?
When your automobile jerks, stumbles, or stutters while you’re driving, it usually signifies that something is obstructing the transmission’s ability to distribute and transfer power properly.
Another scenario is if you haven’t developed the feel of shifting for your specific car while using a manual transmission.
Q: Does a dirty air filter cause your car to jerk?
The purpose of the air filter is to keep airborne dirt and debris from entering the engine. If it’s unclean, it might prevent air from reaching the engine, which would reduce the amount of oxygen the engine receives.
Due to the imbalanced oxygen-to-fuel ratio caused by this, the engine misfires, and the vehicle jerks.
Q: Can low oil cause the car to jerk?
Your automobile may jerk or hesitate while you are driving if the oil is dirty or low. This is a result of the engine not receiving the lubricant it needs to function properly. It’s crucial to have your car evaluated by a mechanic if you detect any jerking or hesitation while driving.
Q: How do you know if spark plugs are bad?
Start-up issues, rough idling, sluggish acceleration, declining fuel economy, engine misfiring, and engine knocking are some of the most typical symptoms of faulty spark plugs.
Q: How do I stop my transmission from jerking?
- Check and top off if there is a low fluid level. If you drive a lot, you should check your transmission level every two weeks or once a month.
- Drain and refill any worn-out or burned-out liquid. It’s recommended to leave replacing the transmission fluid to a professional because it can be dirty.
Q: Can low fuel cause a jerk when accelerating?
When you accelerate, your car can also seem like it’s dragging something, and it might even jolt or jump when you let up on the gas. With all of them, the cause is frequently a lack of spark, air, or fuel during the combustion process.
Q: How do I know if my transmission is bad?
- Refusal to Switch Gears.
- Burning Smell.
- Noises When in Neutral.
- Slipping Gears.
- Dragging Clutch.
- Leaking Fluid.
- Check the Engine Light.
- Grinding or Shaking.
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.