How to Clean a Dirty Throttle Body? | Symptoms Of a Dirty Throttle Body

The fuel injector system is one of the most important parts of your vehicle. The throttle body is a major part of the fuel injection system. The two most common car maintenance jobs are fuel injector cleaning and dirty throttle body cleaning. A dirty or bad throttle body may badly damage your engine or reduce the engine performance. This article mainly explains the symptoms of a bad throttle body, its cleaning cost, and how to clean it.

Symptoms Of a Dirty Throttle Body

The throttle body is a vital component of the fuel injection system that controls the amount of air entering the engine cylinder.

Symptoms Of a Dirty Throttle Body

When the throttle body is in good condition, the engine will achieve the ideal air/fuel ratio and run at its best. But as the throttle body is clogged or damaged, you will notice a clear reduction in the engine power, and your engine will start to consume more fuel than usual.

A dirty throttle body generates one of the below-given symptoms:

  1. Illuminated check engine light
  2. Grime build-up
  3. Rough idling
  4. A reduction in engine power
  5. Poor acceleration
  6. Stalling idle
  7. Poor fuel economy
  8. Engine misfires

1) Illuminated Check Engine Light

The illuminated check engine light is one of the first symptoms of a bad or dirty throttle body. Multiple sensors (such as the throttle position sensor) are mounted in the throttle body. The Check Engine Light illuminates when the vehicle’s powertrain control module (PCM) monitors an issue with the throttle body signal.

check engine light

Your check engine light may also come on for other reasons as well. Because of this, it’s a good idea to go to an auto professional and have your vehicle scanned for trouble codes when you put it on the dash.

Read More: Causes of Check Engine Light 

2) Grime Build Up

As you can imagine, a major reason why the throttle body needs cleaning is due to the buildup of contamination inside the part (i.e., coking). The contamination buildup inside the throttle body produces a rough surface that disrupts the flow of air and fuel and reduces engine efficiency. The carbon buildup may produce similar problems due to uneven surfaces within the parts.

3) Rough Idling

Rough idling is one of the common symptoms of a dirty throttle body. The rough idling indicates that your throttle body is damaged or clogged and needs cleaning or replacement. However, your engine may rough idle due to many other reasons. Therefore, when your car starts rough idling, drive your car to a professional for proper inspection.

Rough Idling

4) A reduction in Engine Power

One of the clear symptoms of a dirty throttle body is that the car engine loses power. As mentioned above, the throttle body has the responsibility to direct a precise amount of air into the combustion chamber for the best performance.

Reduced engine power due to dirty throttle body

A defective or clogged throttle body will allow too much or too little air into the engine cylinder. This further reduces performance, and your vehicle can’t run as fast as expected.

The main function of the throttle body is to permit a specific amount of air into the engine cylinder when you step on the gas pedal. Additional fuel and air enter the engine combustion chamber, creating more power and increasing the vehicle’s speed. When the throttle body fails, there will be no increase in power because there will not be sufficient air.

5) Poor Acceleration

A faulty throttle body either permits more air into the air/fuel ratio or reduces the amount of air needed for optimal combustion.

acceleration problems

When any part of the throttle body goes bad, your vehicle faces acceleration issues. In such conditions, you may experience jerky acceleration, or the car stops accelerating at a certain point. Both of these issues badly affect your car’s performance and significantly reduce your car’s mileage. Engine life is also a big issue.

6) Stalling Idle

The dirty throttle body affects RPM in other ways as well. It may reduce the idle speed due to that your engine may stall. This usually happens when there is a lot of soot and contamination on the throttle body’s tail. As a result, less air gets into the engine, and the idle speed drops.

engine Stalling due to dirty throttle body

Cleaning the throttle body and calibrating the throttle body with a diagnostic tool can often fix this problem.

7) Poor Fuel Economy

A clogged throttle body can significantly impact your vehicle’s fuel economy. The poor fuel economy indicates that your throttle body needs cleaning. A vehicle’s mileage is best measured from full tank to full tank.

You must fill up your gas tank and register your odometer or reset one of your trip meters to zero before you can use your vehicle. If the tank is empty, refill it and repeat all the steps again.

Divide the distance traveled by the amount of fuel used. This will provide the mileage of your car. If the difference between two full tanks of fuel is more than 15 percent, your vehicle may have a throttle problem.

8) Engine Misfires

A misfire is a telltale sign of a dirty throttle body. Misfires typically occur when there is an air/fuel ratio problem.

This typically happens when the air/fuel ratio is very bad, or the spark plugs generate a weak spark. Simply put, the engine starts misfiring when the air-fuel mixture doesn’t properly combust in the combustion chamber. A misfire can mean that the condition of the car’s engine is not optimal.

engine Misfiring

A dirty throttle body can change the air/fuel ratio and be the major reason for engine misfires. The misfiring is generally thought of as small knocking noises that occur when the engine is revved up.

How to Clean a Throttle Body?

The throttle body cleaning may save you more money than replacing it.

You must have the following tools and materials while cleaning a dirty throttle body:

  • Screwdrivers set- Torx screwdrivers.
  • Rubber gloves
  • Safety goggles
  • Cotton swabs
  • Soft toothbrush
  • Paper towels
  • Work light
  • Household oil
  • Pliers
  • Throttle-body cleaner: You must have this cleaner at your auto parts supply store. Don’t try to use carburetor cleaner.

Follow the below-given steps to clean the throttle body:

  1. Disconnect the battery
  2. Locate the throttle body
  3. Remove the big intake hose
  4. Remove the throttle body
  5. Open the throttle body flap
  6. Spray throttle body cleaner
  7. Clean the throttle body
  8. Reinstall the throttle body
  9. Reinstall the intake hose
  10. Throttle body calibration
  11. Clear trouble codes and test drive

These steps are explained below:

Step 1: Disconnect the Battery

To be on the safe side, remove the negative terminal of the vehicle battery to prevent a short circuit.

Step 2: Locate Throttle Body

After removing the negative terminal of the battery, find the throttle body. The throttle body is usually mounted in the intake manifold. You can also check the vehicle manufacturer’s manual to find your throttle body.

Throttle Body location

Step 3: Remove the Big Intake Hose

Once you locate the throttle body, remove the large hose clamp and eliminate the hose so you can approach and view the throttle body.

Big Intake Hose

Step 4: Remove the throttle body

This is an optional step. You can either detach the throttle body and clean it properly, or you can sit down and properly clean it without removing it from the intake manifold.

throttle body

Step 5: Open the throttle body flap

For proper cleaning of your throttle body, use a screwdriver or your finger to open the throttle body flap. If you want to clean your vehicle’s throttle body without removing it, this process may be more complicated than removing it.

throttle body flap

Step 6: Spray Throttle body cleaner

Take the throttle body cleaner like brake cleaner. Properly spray both sides of the throttle body flap and leave for 5 minutes or follow the directions written on your throttle body cleaner.

Spray Throttle body cleaner

Step 7: Clean the throttle body

After waiting for a while, grab a paper or cloth and start cleaning your dirty throttle body. Properly clean the sides of the throttle body and flap valve. Make sure that the flap valve edges are cleaned properly.

throttle body cleaning

Step 8: Reinstall the throttle body

After proper cleaning, reinstall the throttle body. All hoses and other parts must be properly installed and torqued the bolts according to the service manual specifications. If a large amount of coolant spills out when removing, add more coolant.

throttle body installation

Read More: Symptoms of Low Coolant

Step 9: Reinstall Intake Hose

Reinstall the suction hose and re-tighten the clamps. If your vehicle has a turbocharged engine, you need to make sure the throttle body surface and hoses are free of grease and other contamination. Otherwise, the pressure of the turbo can cause the hose to burst.

Intake Hose reinstallation

Step 10: Throttle body calibration

Modern vehicles require a throttle body calibration after the completion of cleaning. Some vehicles perform this step automatically when you turn the ignition on and off. So, you can try turning the ignition key on and off a few times to see if it fits. But if your vehicle doesn’t run efficiently after cleaning, you may need to calibrate it using an OBD-II scanner.

Throttle body calibration

Step 11: Clear trouble codes and test drive

After adjusting the throttle body, you must clear all trouble codes if you use a diagnostic scanner. After this, perform a test drive of your car and look for signs of trouble or warning lights on the car dashboard. You have successfully cleaned the throttle body and saved money if all goes well!

How to Clean a Throttle Body Without Removing it?

If you want to clean the throttle body without removing it, the process is similar but with a little more care. However, throttle body cleaning without removing it is a little bit complex.

Follow the below-given steps to clean a throttle body without removing it:

  • Use a screwdriver to open the throttle valve
  • Properly spray the throttle body cleaner
  • Use a paper or cloth to wipe off the dirt from the throttle body. Don’t try to drop the cloth in the intake manifold.

The throttle body cleaning without removing it is to not spray too much cleaner and be very careful not to drop something inside the intake manifold.

Spray Throttle body cleaning without removing it

Unfortunately, if you have dropped anything into the intake and cannot remove it, you must detach the intake manifold and remove the object before starting the engine.

Throttle Body Cleaning Cost

The cleaning of the throttle body depends on your living area, labor cost, and the make and model of your vehicle.

The average cleaning cost of the throttle body is from $190 to $320. In this cost, the cost of the parts will likely be $5 to $20. However, a can of CRC Throttle Body Cleaner will most likely cost less than $9 at your average auto parts store.

FAQ Section

How often should the throttle body be cleaned?

There is no hard and fast rule to clean a throttle body after a specific distance. However, it is recommended to clean the throttle body every 19,000 to 30,000 miles, but this number may change according to the engine condition and driving habits.

Can I Clean Throttle Body While Engine Is Running?

Yes, you can clean the throttle body while the engine is running. However, in this process, there are high chances for the throttle body cleaner to enter the engine cylinder. This cleaner is very dangerous for oil seals and gaskets. Therefore, excessive exposure of these parts to this substance can damage the oil seals and gaskets. Therefore, it is recommended to clean the throttle body with the engine off.

What Is the best Throttle Body Cleaner?

A professional certified throttle body cleaner is perfect for your throttle body. Usually, certified cleaners are made from environmentally friendly materials. The cleaner doesn’t damage the internal parts of the engine. One magic cleaner is CRC 05078 Throttle Body and Intake Cleaner.

Can I use Carburetor Cleaner on Throttle Body?

Yes. You can use a carburetor cleaner, but the carburetor cleaner will not pick up heavy dirt. Therefore, more must be used to remove all of the carbon accumulation.

How long does it take to clean a throttle body?

The throttle body uses to control and regulate the amount of air entering the combustion chamber. If it gets dirty, your engine will not idle smoothly. So, before driving your vehicle to a mechanic, clean the throttle body for about 12 minutes using a spray can of throttle body cleaner and paper towels.

Does the fuel injector cleaner clean the throttle body?

Fuel does not flow through the throttle body. Therefore, adding fuel to the fuel tank doesn’t help to clean the throttle body.

Can I clean my throttle body myself?

Yes. The cleaning fuel injector isn’t typically a DIY job, but you can use common tools and a specific spray cleaner to clean your vehicle’s throttle body. Regular cleaning of the throttle body cleaning is a great factor for your vehicle maintenance, but it also helps with the drivability of your engine.

How do I reset my throttle body after cleaning?

Make sure that the accelerator pedal is fully released. Turn the ignition switch “ON” and wait at least 2 seconds. Turn the ignition switch “OFF” and wait at least 10 seconds. Turn the ignition switch “ON” and wait at least 2 seconds.

What are the signs of a clogged throttle body?

  1. Illuminated check engine light
  2. Grime build-up
  3. Rough idling
  4. A reduction in engine power
  5. Poor acceleration
  6. Stalling idle
  7. Poor fuel economy
  8. Engine misfires
Read More
  1. Engine Cooling System Working and Function
  2. Symptoms and Causes of bad Throttle Position Sensor
  3. Why does your Car Shut Down While Driving?
  4. Pros and Cons of Head Gasket Sealer

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