15 Confirmed Reasons Why Your Car Jerks When accelerating

15 Confirmed Reasons Why Your Car Jerks When accelerating

Over the years, cars have gone through numerous innovations, and several issues have been curbed forever due to these updates, but car jerking is one of those issues that are still prevalent in vehicles.

When accelerating, car jerks are a warning sign indicating that your vehicle has some underlying issues, and most of these issues worsen over time if you do not resolve them promptly. 

in this article i will highlight the most common reason why car jerks when accelerating and answer some of your most worrying questions.

Here are some of the reasons why your car jerks when accelerating and even when slowing down —

1. Spark Plugs

The work of the spark plugs is to ignite the fuel cylinders with sparks. Unfortunately, the cables in your car are sensitive, so if the spark plugs are dirty or worn, the engine won’t function properly. Also, jerking and other issues will start surfacing when you drive. 

If the spark plugs have worn out, you’ll have to change them immediately. If it is dirty, you can clean it, and your car will return to its optimal running levels. 

2. Injectors

The injector is one of those parts that people don’t pay lots of attention to. However, if your car is jerking, then the engine is misfiring as well, then you should know that the fuel injector is causing this. 

This part deals with the amount of fuel necessary to reach your engine, so if carbon deposit clogs its openings, then your machine will lose its efficiency. 

You’ll have to clean the fuel injector with a special kit used for such activity to solve this issue. Then, you can check online or visit an auto parts store to get it. After cleaning it, the injectors should start working well. 

If you don’t want this issue to repeat itself, you have to be cleaning the injectors regularly. 

3. Catalytic converter

The catalytic converter is one of the vital parts of a car’s exhaust system. This part is where harmful exhaust gasses are broken down, leaving the vehicle as a byproduct of combustion. 

If the fuel and air mix up in the engine, it will affect the exhaust by making your car jerk when accelerating. 

The second occurrence that could cause car jerks is a clogged catalytic converter. Once it gets blocked, the exhaust will not flow out, thereby reducing the engine performance. If your catalytic converter is clogged, you’ll notice it quickly because it will smell like rotten eggs, and then the fuel economy will decrease. 

4. Limited air Intake

When you’re driving at high speed, your engine will take in large quantities of air so it can power the combustion. Interruption of the airflow will lead to acceleration issues, which include jerking. 

What causes this interruption of airflow is usually because the air filter is heavily soiled. However, in some cases, it could be that the intake duct has spoilt. 

5. Airflow sensor malfunction

Nowadays, some cars measure and control moving components of vehicles with sensors. If the sensors have an issue, then the engine components will receive wrong information, which will make them unresponsive. Therefore, the check engine light should turn on if this is the issue.  

6. Wrong Alignment

If the engine and rotor are not the two leading causes of this issue in your case, then it is an alignment issue. You’ll feel like the car is jerking, but instead, it is its slow speed that makes you think that. 

The first place to check is the tires. You will study for low tire pressure to see if you need to inflate it. You can also change the tire to a new one if you notice it’s already wearing.

Suppose the other components of your car where the tire goes are messed up badly. Then you’ll have to align the parts so your vehicle will function properly.

7. Ignition system issues 

Different irregularities could occur when accelerating. You don’t always have to be going at high speed to notice this issue. 

The leading cause of this is the loss of spark at that moment, thereby leading to incomplete combustion, which causes a terrible engine lope. 

Some of the causes of this issue are spoilt plug wires, worn spark plugs, and problems with the coil/coil pack, and so on. 

8. Moisture Under Distributor Cap

The engine distributor is the component that delivers sparks to the spark plugs wires when it’s needed. The only time it won’t work is if its cap seal is faulty or it has cracked. If any of these happen, it will lead to water ingress. 

This issue is most likely to occur during winter if you leave your car outside. Once this happens, moisture will accumulate under the distributor cap, causing an imbalance in the engine, and when a motor isn’t balanced, a misfire will occur. 

To avoid this issue, do not park your car in an icy spot, and you shouldn’t allow heavy rain to fall on it consecutively. Instead, always try to park your vehicle in a warm place. 

9. Air in ABS System

An ABS module is used on modern vehicles nowadays. This module is used to vary the degree of brake pressure in times of emergency to prevent your car from skidding. For the ABS to function correctly, there must be no air. 

If The Mechanic worked on your brake and your car starts jerking when you accelerate, not all the air was taken out of the braking system. 

10. Warped rotors

To slow a car’s progression, friction is needed between the set of brake pads and their rotors. Unfortunately, as with all parts of your vehicle, they all wear and need to be replaced. 

If that is the case, your aging brake rotors will have to be changed because they will start overheating and cause thermal shock, which will lead to car jerks when you press the gas pedal.   

11. Low transmission fluid 

A good supply of this fluid is needed for an automatic transmission so that the torque converter will operate well. If you have low transmission fluid, or the liquid has gone wrong, it will lead to delayed shifts. If you do not attend to this issue for an extended period, it can cause lasting damage to your vehicle. 

12. Vacuum leaks

If any unmetered air makes its way into your engine intake, it will lead to issues with the idle. A vacuum leak is an issue most likely to occur. This issue usually occurs at the information ducting/gaskets and hoses. 

13. Faulty IAC Valve

A vehicle’s engine will receive a significant load if the A/C compressor is engaged. The issue that will present itself is jerking/stalling if the air idle control valve fails.

14. Worn Throttle Cable

Some vehicles are designed with a throttle plate that is cable-driven. If your car has such a design, then it could be that the cable has worn out, and it’s the cause of your car’s jerking issues. 

15 Damaged Clock Spring Wiring

If the cruise control is engaged, yet your car still jerks when accelerating, this means the clock spring has spoilt. 

To spot the clock spring, look for an electric pigtail that is wound and mounted to your car’s steering wheel. Accessories of the steering wheel that rotates will be able to function with the help of the pigtail. 

Why does my car jerk when shifting transmission?

When your car jerks when shifting transmission, this occurrence is known as jerking transmission or rough shifting. 

If your car is experiencing this, you’ll have a hard time changing gears, accelerating, and transitioning won’t be smooth. This issue occurs as a thud feeling when you try shifting from one gear to another. There are three leading causes of this —

• Faulty sensor – nowadays, many vehicles have lots of sensors installed in them so they can communicate with the vehicle’s internal computers. For the transmission to shift, a sensor will have to empower it. If any of the sensors aren’t functioning well, they will deliver incorrect data, leading to hard shifting. Your vehicle’s speed sensor might give the wrong signal of you driving at a lower or higher speed than you are. 

• Vacuum issues occur on older vehicles because there is a vacuum modulator valve that lets the transmission know when to shift. This valve also determines the load of the engine through a hose that is called the vacuum line. The intake is connected to this hose or vacuum line to measure the vacuum within the machine easily. If the vacuum line gets broken, detached, bent, or blocked, it will alter the pressure in the transmission, and it will make your car jack.  

• Low or contaminated transmission fluid – if your car is low on transmission fluid or if the liquid has gotten contaminated, it will lead to hard shifting, making your car jerk. What usually causes this issue is inadequate lubrication. Not lubricating the necessary parts frequently will lead to strenuous activity and several other problems in different parts of your car. To know if the fluid is clean, it has to look clear (free from debris/diet); it must be a bit transparent and light red.  

Car Jerks When accelerating FAQs

Question: After jerking, why is my check engine light on?

Answer: The check engine light only turns on when your vehicle engine has some faults. You could either accelerate or slow down your car, yet the check engine light will turn on. There are several reasons why this light comes on. You’ll have to carry out a diagnosis to know the exact reason why.  

In some cases, here are the usual issues — a bad/clogged catalytic converter or a faulty mass airflow sensor. If these two aren’t the reason why your car is jerking, then you’ll have to take it to an expert to solve the issue for you. Don’t delay with the repair because it can cause a lot more damages to your engine.  

Question: What causes car jerks when slowing down

Answer: The main reason this occurs is that a faulty mass airflow sensor is dirty. The mass air flow sensor’s job is to monitor the air intake that gets mixed with the fuel before it goes inside the motor. A failing MAF sensor will lead to the improper supply of air or power to the engine, which will either cause under-fueling or over-fueling. If your car jerks when slowing down, you now know the reason why. 

Another reason why this occurs is when moisture is underneath the distributor cap. This issue will appear in only specific makes and models of cars and the ignition type of the vehicle. 

Question: Can car jerk occur because of transmission?

Answer: When you’re driving your car, then its automatic transmission shifts, you’ll feel the car jerking, or it might be stuttering. This shows that you need to either refill the fluid because it is low or it needs to be changed. 

Not only automatic transmission leads to jerking, but a manual transmission can also make your car start jerking. The jerking will occur if the gear synchros is spoilt or if the clutches have worn. But, again, you’ll need to visit a professional mechanic to have this fixed for you the right way. 

Question: Can a bad battery cause a car jerk?

Answer: All cars have battery issues from time to time, and it is always the first place mechanics check too because if enough charge doesn’t get to the battery, the voltage necessary to make your car run smoothly won’t be reached, thereby making your car jerk when accelerating.  

Apart from the lousy battery making your car jerk, you will also notice issues like the hardness in shifting the transmission because of inadequate charge. If you see this, you should expect your car to start jerking because it’s a well-known symptom of a bad battery. 

Question: Can I solve car jerking issues myself?

Answer: Due to the numerous reasons that could make your car start jerking, it’s best to give it to a professional mechanic to help you diagnose the issue and fix it. The only reason that should make you resolve the issue yourself is if you’re a mechanic, or you know the main fault with your car and how to go about fixing it. 

Conclusion

Car jerks when accelerating are annoying and very uncomfortable. I covered all the necessary parts you need to know in spotting the cause of the Car jerks and specific ways to resolve them. To avoid this issue, a frequent inspection and good maintenance will help a great deal.