Carbon Buildup In Throttle Body – How To Tackle This Problem?

Carbon Buildup In Throttle Body – How To Tackle This Problem?

September 8, 2021 0 By CarGuy

Are you experiencing some bad performance from your engine and your car just idles rough? You probably have a carbon buildup in throttle body problem. Although this is strange to imagine, carbon deposits can get inside of the throttle body. Accompanied with years of dirt and grime they can impair the proper work of the throttle body and deem your car to be inoperable.

Throttle body problems can become a big issue in your car. If the throttle body does not work properly you are going to get bad fuel mileage and poor idling. The engine will try to stall all the time and you will have the trouble of keeping it running.

This can also affect you in some situations. Because your car would not be able to start because of this problem. If you can’t start the car you will not be able to go to work and do your daily activities. You are basically stuck in one place and you don’t have a solution. But carbon buildup in throttle body is a thing and it needs to be taken care of and we are going to discuss how you can do this work.

In this article, we are going to cover what is a throttle body. Then we are going to learn what are the carbon buildup in throttle body symptoms. And then we will learn how you can tackle this problem easily at home with common tools. This is important because you don’t want to pay a lot of money to mechanics for something this simple. So, without further ado, let’s get into the article.

What Is A Throttle Body?

A throttle body as its name implies is a component on the engine that based on your gas pedal input decides how much air to release into the engine.

Modern cars have electronically regulated fuel injection and this component is critical in these cars. It basically controls how much air gets into the engine.

How the throttle body works is pretty simple. There is a sensor located on the throttle body that is called a throttle position sensor. This sensor is receiving information on where your foot is located.

This sensor is sending constant updates to the PCM of the vehicle and then the computer decides how much fuel to inject into the system. This system is genius and has a ton of advantages compared to the previous carbureted systems that were analog. They couldn’t measure the air and the fuel. Basically, the adjustment of the carburetor has decided how much fuel to add.

But in the modern systems that we are using now, everything is precise and accurate. So, no fuel is lost in the process and the vehicle is using all the energy correctly in order to deliver proper fuel efficiency.

But unfortunately, there are problems with these throttle bodies. And that is that they become dirty over time and carbon buildup in throttle body problem is starting to appear and ruin your mood.

Many owners don’t know what to do in this situation because they think the spark plugs or some other components are making the problem. But carbon buildup in throttle body is real and is plaguing many cars on a daily basis. But how this carbon gets inside of my car?

How Does Carbon Get Into My Throttle Body?

It is very simple to explain. This carbon is not essentially yours but as you drive your car on the highway there are plenty of vehicles around you that are driving along.

And as the vehicle travels it sucks some of the gasses that are released by these cars. And somehow these gasses get into your engine. These gasses contain a lot of carbon and this carbon sticks to the flaps of your throttle body. And if too much carbon gets stuck on the flap, your throttle body stops working properly.

If your throttle body stops working properly you will experience a lot of symptoms. And we are going to cover all these carbon buildup in throttle body symptoms in the next chapter. So, follow along.

Carbon Buildup In Throttle Body Symptoms

Like with every component in our cars, the throttle body as well is starting to develop symptoms when it goes bad. So, what are the carbon buildup in throttle body symptoms? Let’s find out.

Check Engine Light

The check engine light is probably the first symptom when you have carbon buildup in throttle body. It is unfortunate that when this light turns on you don’t have a clue why it is there and in order to find out you need to troubleshoot. But how you can troubleshoot a check engine light?

For this purpose, you will need to get an OBD2 code reader. This code reader is essential if you want to access your car’s computer. These code readers are fairly inexpensive these days and you can find them for cheap on Amazon or at some local car parts stores.

And they will tell you a lot about your car and your car’s health. When you connect the scanner to the OBD2 port the scanner will scan the car and you will get back the error codes.

On more advanced scanners they will tell you right away what is the issue but when it comes to cheaper scanners you will have to look for the errors online. And if you get an error that is connected to the throttle body. It is worth checking out the throttle body condition. You have to remove the intake tube and see the condition of the flap.

If there is carbon buildup in throttle body you have to clean it off. And how you can clean carbon buildup in throttle body we are going to explain later in the article after we cover all of the symptoms.

Low Or High Idle RPM

This symptom is a dead giveaway that there is something wrong with your throttle body. This symptom will tell you a lot because if your RPMs are below 800 when the car is idling then you know that this is a throttle body issue on your vehicle.

Also, if the RPM is above 800 when the engine is idling the throttle body flap doesn’t work well. It stays too open and allows too much air to get inside of the intake plenum.

If the flap is open then the PCM allows more fuel to be injected into the cylinders. This is also not good and is a clear indication that there is a carbon buildup in throttle body happening on your car.

The throttle body has to come out and you need to give it a good cleaning if you want to return the throttle body in factory condition. And how you can achieve this? We are going to cover that later in the article.

Slow Acceleration

Slow acceleration is also noted. Especially if the flap is stuck close. This closed flap basically impairs the air to enter the intake.

And if there is no air in the intake it means that there will be no input from the throttle positioning sensor to tell the PCM to release more fuel. In order to help the car to accelerate.

This problem can be frustrating because you don’t know what is happening. Some people would misdiagnose this issue with a bad clutch or frozen brake calipers. Because the symptoms are pretty much the same. The car moves very slow or it doesn’t move at all.

And in order to be sure you have to check all these components and make sure that none of them is causing the problem.

Then you should open the throttle body and see the condition of the flap. If it doesn’t want to get open then you have your culprit and now it’s up to you to clean the throttle body and make your car drivable again. But how can you clean carbon buildup in throttle body? Well, we are going to discuss that later in the article but first, see the other symptoms of carbon buildup in throttle body.

Bad Fuel Economy

Bad fuel economy is also another symptom of carbon buildup in throttle body. How this works is pretty simple. The flap stays too open for too long. Then the sensor for the throttle body sends the information to the PCM and the PCM releases more fuel into the combustion.

More fuel into the combustion results in bad fuel economy. This problem can be so bad that your fuel economy might worsen for 5 to 10 MPG less than your standard fuel consumption.

And if you notice how the RPM always stays high and you are visiting the gas station more frequently than usual. Then you know that you got to check your throttle body for possible carbon buildup in throttle body.

If the throttle body was never cleaned before this is probably the root of your problem. Fix the throttle body and you will be good to go. But how you can clean and fix the throttle body? Well, that is what we are going to cover next.

How to Clean Throttle Body DIY?

This is a small guide for all you DIY guys out there who don’t want to leave this work to mechanics who often know to misdiagnose problems on your car.

Knowing to troubleshoot and solve these problems by yourself is going to save you thousands of dollars in the long run and you will also improve your mechanical knowledge and you will learn new things each day.

And that’s in the case with the throttle body. After you read all of the symptoms of carbon buildup in throttle body. Now it’s time to compare the symptoms with your car and see if they match. If they do then you can start the cleaning process. But how you can do that? Let’s explain.

Step 1

Get a screwdriver and remove the boot that is attached to the throttle body. This boot is usually held by a clamp. Loosen up the clamp in order to allow it to come off. Remove the boot and move on to the next step.

Step 2

The next thing you need to do is to remove the throttle body positioning sensor. Just unplug the connector and you will be good to go and move to the next step.

Step 3

The throttle body is held by 4 screws. You need to unbolt the throttle body and remove it from the car. Removing the throttle body will give you a good space to work on the throttle body and to give it a good clean.

Step 4

Get a carb cleaner from your local parts store and clean off the throttle body with the cleaner. Spray it really well and wipe off all the carbon and dirt that has accumulated on the throttle body.

Make sure that you repeat the process until you remove everything from it. This will guarantee that your throttle body is in proper working order.

Step 5

The final step is mounting the throttle body and making sure that everything is nicely connected. If you don’t connect everything as it should the throttle body would not work properly.

Then you are good to go and you can enjoy driving your car once again without any worries of your car stalling or not accelerating.

Conclusion – Carbon Buildup In Throttle Body

In this article, we have learned a lot when it comes to the problem of carbon buildup in throttle body.

We learned the basics of what a throttle body is and how carbon can get inside of the throttle body. Then we have covered all the symptoms that are connected with a clogged throttle body.

And these symptoms were the check engine light, the increased or decreased RPM at idle. Increased fuel consumption as well can be one of the symptoms of carbon buildup in throttle body.

And lastly, we have made a good tutorial on how you can clean a throttle body using carb cleaner. Cleaning your throttle body will guarantee that your throttle body will continue working properly and you will no have any issues with the throttle response on your engine.

If you want to read more about engine problems you might want to take a look on our articles on rod knock symptoms, low oil pressure symptoms and spark plug fouling.