11 Reasons Why Your Car Jerks When You Accelerate
Nothing ruins a ride more than a jerky car when accelerating. Not only is this embarrassing because it makes other drivers think you can’t drive, but it could also lead to costly repairs if you don’t fix the problem right away. Let’s take a look at the main reasons your car may shake or shudder and what you can do to fix it.
Why Does My Car Jerk or Wobble When I Accelerate
You’ll know something’s wrong if you feel like your car twitches, shakes, bounces, or sputters after you step on the accelerator.
You might also notice that your car grinds a bit when accelerating, or jerk or jump when you let go of the accelerator. All of these are usually caused by a lack of fuel, air, or spark during the combustion process. However, there are other causes, and you want to find and fix the problem as soon as possible before it gets worse and becomes expensive to repair.
1) Dirty Injectors
This is a common and annoying problem that can cause a variety of issues. Dirty injectors can cause your car to lose power and your engine to misfire frequently, making your car jerk at certain speeds or from a standstill. You may also hear a sputtering noise in your engine due to irregular fuel delivery.
To avoid this problem, you should clean your injectors regularly. Luckily, this process is easy with a fuel injector or fuel system cleaner. However, injectors can get so dirty with carbon deposits that even the best injector cleaners may not be enough. In these cases, you may need to remove the injectors and clean them manually or simply replace them.
2) Clogged catalytic converter
The catalytic converter is responsible for reducing the amount of pollutants emitted from your car’s exhaust. If the air/fuel mixture in your engine is too rich, over time the catalytic converter can become clogged and cut off the airflow through your exhaust system.
This can cause a stuttering, jerky feeling when you step on the accelerator, and an overall delayed response. Aside from the twitching, other symptoms may include a rotten egg (hydrogen sulfide) smell, reduced fuel economy in your car, and the check engine light coming on.
Using a good catalytic converter cleaner first may help clear up minor clogs. If that doesn’t fix the problem, you’ll need to take your car to an auto repair shop to have the problem fixed. This may require replacing the catalytic converter.
3) Faulty Mass Air Flow Sensor
If your car lurches or lurches forward while driving at high speeds, a faulty Mass Air Flow (MAF) sensor may be the culprit. Its job is to measure the amount of air entering the engine and communicate this information to your car’s computer. The computer then tells the injectors to deliver the right amount of fuel at the right time for the right mixture.
A faulty MAF sensor can cause your car to lurch or lurch forward unexpectedly when driving at high speeds, such as on the highway, which is most noticeable. A bad mass airflow sensor should turn on the check engine light, but this is easy to check with an OBD2 scanner.
4) Faulty fuel pump or filter
The cause of your car jerking when accelerating is often a fuel delivery problem. If the engine isn’t getting the right amount of fuel, it’s often best to restart the engine.
In this case, it would be your car’s fuel pump. If your fuel pump is faulty, it will have a hard time keeping up with the fuel demand, which can cause your car to jerk or lurch forward while driving. Alternatively, the fuel filter may be clogged and restricting fuel flow, which can cause problems due to irregular fuel delivery. Replacing a fuel filter is a relatively easy and inexpensive process.
5) Clogged Fuel Lines
Clogged fuel lines are often caused by a buildup of dirt, debris, or contaminants in the fuel itself, which restricts the flow of fuel to the engine and causes the car to shudder, especially when accelerating at a steady speed.
Often this is due to dirty fuel filters, clogged injectors, or using low-quality fuel. And in case you were wondering, if someone poured sugar (or another foreign object) into your gas tank, a clogged fuel line is just the beginning.
6) Dirty Air Filter
As you read this article, you’ll understand that the cause of your car jerking or sputtering when accelerating is often an improper air-fuel mixture. The other side of the fuel side is a proper air supply. Not enough air getting into the combustion chamber often causes the same problems as too little fuel.
Your car’s air filter is your first line of defense against dirt and other foreign objects. A dirty air filter can allow particles into your engine, affecting performance and causing jerks.
Check the condition of your air filter. If it’s dirty, replace it. Replacing it should only cost $10-20 and take just a few minutes. Alternatively, buy a reusable air filter like this one from K&N, so you can clean it later instead of replacing it. A clean filter will significantly extend the life of your car’s engine and, among other things, reduce or eliminate sudden changes in acceleration.
7) Faulty Spark Plugs
One of the most common causes is also one of the easiest to identify and fix. During the combustion process, a good spark is needed to properly ignite the fuel in each cylinder.
A bad or dirty spark plug can prevent this proper ignition and will cause the engine to misfire. While driving, it feels like your vehicle jerks or shutter when accelerating.
Fixing this problem is as easy as replacing the bad plug. If you don’t remember the last time you replaced your spark plugs, it may be a good idea to get them all changed out. This is a quick and inexpensive repair.
8) Low Transmission Fluid
Having low transmission fluid in your car can cause several issues, one of which includes jerking when accelerating. When your transmission fluid gets low, it can lead to issues such as gears slipping or a lack of lubrication in the transmission system, both of which can result in a jerking, jumping, or lurching sensation.
It’s crucial to regularly check and maintain the appropriate level of transmission fluid.
9) Distributor Cap Moisture Buildup
On colder days, condensation can form under the distributor cap. This mainly occurs when you have the car parked outside overnight. This moisture will cause the engine to misfire, thus your car will jerk when accelerating at low speeds.
Luckily, the problem will go away once the water is gone, but repeated moisture buildup can tax your engine over time.
You can avoid this issue altogether by ensuring your car’s parked in a garage or other protected location. A thermal cover can also help reduce the risk of condensation when shelter isn’t an option and you’re expecting colder weather.
10) Worn Accelerator Cable
While most cars on the road use drive-by-wire electronic throttle control to accelerate, a physical accelerator cable (or throttle cable) are still found in many vehicles. It acts as a mechanical link between the gas pedal and throttle plate.
Over time, this accelerator cable can wear out. This will cause the car to respond more slowly when you press on the gas and it lurches instead of providing smooth acceleration. You can usually see damage to the cable’s outer coating when examining it, making this problem easy to diagnose.
A damaged cable requires immediate attention, as the car can stop functioning when the cable breaks. Be sure to take it to a trusted mechanic to ensure the replacement is done right.
11) Bad Transmission Control Module
If you drive an automatic transmission car and notice your car jerking or bucking right around the time your transmission changes gears, you may have a faulty transmission control module (or solenoid).
This part is responsible for gear changes when you accelerate. Gear shifts may be delayed or unpredictable and are often harsh and may feel like the car jerks. While not a common point of failure, it’s worth considering while you troubleshoot.
