Your Car Jerks When Stopped at Light? Here is What To Do!

If you’ve ever been stopped at a red light in your car and felt it jerk, then you know how alarming the situation can be. Usually a faulty coil pack or dirty throttle body can cause a car jerks when stopped at light, but there could be other factors at play.

Fortunately, this issue is usually not serious, but that doesn’t mean it’s something you should ignore. Identifying the cause of the jerking is essential for keeping your car running smoothly and safely. Let’s take a look at these  potential causes in more detail.

2 Common Causes Make Your Car Jerks When Stopped at Light

2 Common Causes Make Your Car Jerks When Stopped at Light

Faulty Coil Pack 

If your car jerks or shakes at red lights, a faulty coil pack could be the cause. The coil pack delivers power to spark plugs, igniting fuel in each engine cylinder.

Over time, packs can wear out and lose efficiency, causing misfires and rough idling. This can lead to jerking when stopped at red lights. If your vehicle experiences this, replacing the coil pack should quickly resolve the issue.

Replacing a coil pack is a necessary expense to ensure your vehicle operates reliably. The cost can range from $130 to over $300, depending on the make and model.

It’s crucial to recognize that replacing the coil pack may require more complex repair work than expected. Seeking assistance from a qualified professional is advisable rather than attempting a DIY approach.

Dirty Throttle Body 

Another cause of jerking at red lights is a dirty throttle body. It’s typically positioned between the air filter housing and the intake manifold of an internal combustion engine. This component regulates air flow by adjusting itself based on accelerator pedal pressure.

The throttle body consists of a valve connected to the accelerator pedal. Pressing down on the pedal opens the valve, allowing more air into the engine. Over time, dirt and debris can build up, clogging the throttle body and affecting its movement. This can result in jerky movements when stopping and poor acceleration from a dead stop.

Cleaning or replacing your throttle body should fix this issue for good. The cost can vary depending on your car’s make and model, and whether you have a professional mechanic resolve it. Cleaning the throttle body can cost $200 to $300, while replacing it can range from $400 to $600.

Mechanics often dismantle the entire air intake section of your vehicle to prevent future issues. This can result in higher costs as it takes longer to remove, inspect, and reassemble other parts and components. Evaluate all costs before starting the service to avoid surprises.

Two common causes of a car jerking when stopped at a light are bad spark plugs, vacuum leaks, or dirty fuel injectors. If it jerks while accelerating or driving at a constant speed, it could be due to other factors.

If you can’t fix the problem yourself, it’s best to take your car to a qualified mechanic. They can diagnose the issue and recommend a solution. With this information, you can get your car back in top shape and enjoy a smooth ride. Take care of the issue promptly to stay safe on the roads!

How Often Should You Clean Throttle Body?

How Often Should You Clean Throttle Body

The frequency with which you should clean your throttle body will depend on several factors such as driving habits, road conditions, type of vehicle, etc.

Generally speaking, it’s recommended that you clean your throttle body every 15-20 thousand miles or once a year if you are not sure how many miles are on your vehicle’s odometer.

It’s also a good idea to inspect your throttle body regularly in between service intervals, make sure there are no cracks or other signs of damage that could affect its performance.

Additionally, if you notice any strange sounds coming from your engine or poor acceleration while driving, these could be signs that something isn’t right with your throttle body and should be checked out as soon as possible.  

How Can I Clean My Throttle Body at Home?

How Can I Clean My Throttle Body at Home

Luckily, cleaning the throttle body is a relatively simple process that can be done at home with minimal tools and time. Let’s take a look at what you need to do in order to get your engine running more efficiently. 

What You’ll Need 

Before we get into the nitty-gritty of how to actually clean your throttle body, let’s first go over the supplies you will need for the job.

To properly clean the throttle body, you will need an air compressor or air gun, a set of nut drivers or wrenches (depending on what type of bolts secure your intake manifold), three cans of throttle body cleaner, and some rags or paper towels.

You may also want some gloves for extra protection if you are sensitive to chemicals. All of these items should be easy enough to find at any local auto parts store or online retailer. 

How To Clean Your Throttle Body 

Now that you have all of the supplies necessary, it’s time to get started on cleaning your throttle body!

  1. First, make sure that the engine has cooled off completely before beginning any work as hot engines can be dangerous and cause injury.
  2. Once it has cooled off enough, locate the air intake tube on your vehicle and remove it from its bracket with either nut drivers or wrenches (depending on what type of bolts are used).
  3. Once this is done, use an air compressor or air gun to blow out any debris that may have collected inside the tube.
  4. Next, spray some throttle body cleaner directly onto the inside walls of the tube and wipe away any dirt and grime with either a rag or paper towel.
  5. Finally, reattach the air intake tube back onto its bracket and start up your vehicle—you should immediately notice increased performance!   

Cleaning your throttle body is an easy way for car owners to improve their engine performance without having to take their vehicles into shops for expensive repairs or replacements.

With just a few simple steps and minimal supplies from your local auto parts store, you can keep your engine running smoothly for years down the road!


Your car jerking when stopped at light can be caused by several different issues such as faulty coil packs or dirty throttle bodies. Identifying what’s causing this behavior in your vehicle is important for keeping it running smoothly and efficiently so that you don’t experience any further problems down the road.

If you’re having trouble determining what’s causing your car to jerk while stopped at red lights, it may be best to take it into an automotive service shop where they can identify and diagnose any underlying problems more accurately than you could do yourself.

Photo of author

James Todd

I'm James, I've been a car mechanic for as long as i can remember, It's always been my dream to work on cars and i love it more than anything. I love the challenge of figuring out what's wrong with them. I'm good at my work and people often come to me for advice. I'm happy to help out whenever i can and i always try to learn something new. I enjoy nothing more than helping people keep their vehicles running smoothly - It's what makes me happy.

Leave a Comment