Despite the convenience of owning a car, they require periodic maintenance to ensure it performs effectively and preserves its lifespan. However, professional servicing can be expensive, so most car owners prefer doing the less complex tasks themselves. One essential component in fuel-injected vehicles is the throttle body, which requires periodic cleaning.
Fortunately, cleaning the throttle body is easy, and you won’t have to remove it for the procedure. To do this, turn the car on and press the gas pedal to open the valve manually. Then spray some throttle body cleaner inside the component and wipe the dirt with a clean cloth or toothbrush.
Our article explains the common symptoms of a bad throttle body and the cleaning procedure without removing it from your vehicle.
What is throttle body cleaning?
The throttle body is a component of the air intake system in a traditional spark ignition gasoline engine that regulates the amount of air entering the engine’s combustion chamber.
It is typically between the air filter and intake manifold, consisting of a housing unit with a throttle plate/butterfly valve that rotates on a shaft. On older carbureted engines, the throttle body is inside the carburetor.
Over time, dirt, grime, and carbon deposits accumulate inside the throttle body, causing stalling, rough idle and vehicle performance issues. Therefore, the throttle body needs periodic cleaning to ensure the smooth running of the engine.
What are the symptoms of a dirty throttle body?
When the throttle body is in working condition, the engine receives the ideal air-fuel ratio for optimum performance. Therefore, a dirty and clogged throttle body impacts the engine’s performance.
Thankfully, there are symptoms you can watch out for to indicate dirt in the throttle body, allowing you to fix the issue before it causes irreparable damage.
Here’s how to tell you to have a dirty throttle body:
Check engine light
Any problem with the throttle body will always trigger the check engine light. The throttle body contains sensors that constantly monitor throttle body performance. If the ECU detects an issue, it will cause the check engine light to illuminate.
There are also several other reasons why the check engine light illuminates, so you’ll need an expert to check on any relevant error codes.
Poor or rough idle
Usually, when your throttle body is underperforming, you’ll notice rough or low idle and strange sounds. If the clogging on the throttle body is severe, the vehicle may even begin to stall when coming to a stop, stalling when you apply the accelerator pedal quickly or low idle while starting.
In addition, the dirt reduces airflow into the system, leading to a fluctuating idle speed.
Uneven or slow acceleration
When you press down the accelerator pedal, there is increased airflow and fuel into the engine. But a throttle body clogged with dirt will reduce air and fuel intake, which causes accelerating issues. As a result, your vehicle will either have uneven acceleration or won’t accelerate at all.
Misfires
Misfires usually occur due to incomplete combustion; either the air-to-fuel mixture is wrong, or there is a weak spark from the spark plug. And since a bad throttle body affects the air-to-fuel mixture ratio, it will cause your engine to misfire.
Poor fuel mileage
A bad throttle body messes with the fuel economy of your vehicle. If you notice you’re refueling more frequently or rarely, then you probably have a choked throttle body.
To measure the mileage of your vehicle;
- Put a full fuel tank, note the odometer readings and then drive for a few hundred miles.
- Fill the tank again and take note of the amount of fuel consumed.
- Then divide the distance traveled by the fuel consumed; that’s your car’s mileage.
If there is more than a 10%-15% variation, it’s most likely a clogged throttle body.
Electrical problems
Modern cars are becoming more reliant on electronic connections and sensors. So if the throttle body sensor is covered in dirt and grime, it will send delayed or false information to the ECU, thus resulting in an incorrect air-fuel mixture. This forces the vehicle into a secondary power-reduced mode, affecting some electrical functions in your vehicle.
Poor engine performance
The engine requires both sufficient air and fuel supply to work effectively. So if a clogged throttle body prevents adequate air supply, the engine’s performance will drop considerably. As a result, you’ll notice the car feels like it’s losing power.
Can you clean your throttle body without removing it?
Removing the throttle body for cleaning is a complex task and requires mechanic skills. Therefore, the best way for anyone without expert skills to clean the throttle body is by leaving it inside your vehicle to avoid damaging it.
If your car shows signs of a dirty throttle body, follow the guide below to clean it without removing it from your vehicle.
Things you’ll need
- Clean microfibre cloth or a soft toothbrush
- Throttle body cleaner
- Screwdriver set
- Work light
- Pliers
- Safety goggles
- Rubber gloves
- Paper towel
Procedure
Find the throttle body.
- Before cleaning, you must disconnect the battery’s negative terminal to avoid short circuits.
- Then locate the throttle body under the hood in your engine compartment.
- The throttle body is an aluminum round valve between the air filter and intake manifold.
Access the throttle body
- Then detach the air intake duct and hoses held in place with a clamp to access the interior of the throttle body.
- Disconnect the clamp holding the rubber in place by using a screwdriver to unscrew the screws and remove the air duct and hoses gently.
- Check if an electrical wire is connected to the air duct and disconnect it.
- Once you remove the air ducts, you can see the rotating plate inside the throttle body. Be careful not to damage any gaskets inside it.
- If removing the air ducts and hoses is impossible, then do not continue. Instead, take your vehicle to a mechanic to clean the throttle body.
Move the throttle to the open position.
- To access the inside of the throttle body, you’ll need to place the throttle place in an open position.
- To do this, have someone press down the gas pedal. Do not try to open the throttle plate by hand, as it could confuse the car’s computer and cause the need for a reset.
Clean the throttle body
- Wear your safety gloves and goggles to prevent eye and skin irritation from the cleaning product. Spray some throttle cleaner inside the body, then use a brush to loosen the grime. Do not overspray the throttle body cleaner to avoid overflooding the engine.
- We recommend spraying about 3-4 times on the plate and the interior of the throttle body.
- Allow the cleaner to sit for about five minutes to loosen the dirt and grime, or follow the manufacturer’s instructions.
- You can also use a carburetor cleaner as a throttle body cleaner alternative. Unfortunately, carb cleaner is less abrasive than throttle body cleaner. So you may have to use more of it and allow it to soak longer if you have a particularly dirty throttle body.
Clean the throttle body with a towel
- Take a clean towel and clean the interior of the throttle body. Ensure you clean the plate and sensors too.
- Wipe the throttle body cleaner with paper towels to leave it dry and ensure no moisture is on the throttle body.
- Use towel paper to wipe dirt residue and cleaner spillage around the throttle body and engine.
Reinstall the air intake duct
- Once the throttle body is clean, reinstall the air intake ducts by tightening the screws on the clamp.
- Reconnect any electrical wires and the battery negative terminal.
- Finally, start your engine to see if it’s running smoothly. You should notice a difference in engine performance, sound, and fuel economy.
- If your car doesn’t start immediately, depress the gas pedal to the floor and start it again.
- You can use the same procedure when cleaning an electronic throttle body in place.
You need to repeat this cleaning process every 60,000-75,000 miles to reduce the accumulation of dirt, grime, and carbon deposits and keep your engine running effectively. However, some mechanics advise against cleaning the throttle body too regularly as you avoid accidentally damaging it during the procedure, using the wrong cleaning products, or failing to reinstall the air intake system.
Can you damage a throttle body by cleaning it?
Properly cleaning the throttle body should not damage it. But if you mishandled any parts, used the cleaning product incorrectly, or didn’t adequately clean the throttle body, it could damage the body.
The throttle body is an essential component in the combustion process. So without it, the engine will not run at all. If not cleaned properly, the remaining dirt will continue causing engine issues. On the other hand, improper cleaning can also cause vacuum leaks, electrical problems, and high idle.
What to do if you spray too much throttle body cleaner?
If you overflood the engine with throttle body cleaner after cleaning the throttle body, the engine will continue stalling. Therefore, you should keep cranking the engine to clear the product until it finally starts.
Common problems after cleaning a throttle body and their fixes
Some of the problems you could experience after cleaning the throttle body include:
High idle
If you do not thoroughly clean the throttle body, the leftover dirt inside the throttle body will cause a high idle. You will notice stalling when accelerating rapidly or stopping at a traffic light when you drive your car after a throttle body clean.
This, in turn, reduces the effectiveness of the engine. If the component is extremely dirty, you may have to go to a professional mechanic for a deep clean.
Torn intake hoses
You can also damage the intake houses when cleaning the throttle body. If the air intake hoses tear, you will experience high idle. Again, the best solution is to replace or repair the hose.
Vacuum leaks
If you roughly handle the throttle body cleaning, the throttle body will allow more air into the engine, resulting in a vacuum leak. This vacuum leak will cause a too-lean situation. To fix this, check the vacuum hose for leaks and replace it if necessary.
Electrical problems
When cleaning the throttle body, it’s best to ensure the interior sensors are clear of all dirt and carbon deposits. If you don’t clean them properly, the sensors will continue to interpret signals incorrectly and, in turn, relay inaccurate information.
You must go back and clean the sensors to fix this issue. If the electrical issues persist, you will need an OBDII scan tool to diagnose and repair the issue.
Conclusion
If your vehicle experiences the symptoms explained, and you notice excess dirt and grime on the throttle body housing’s inner walls, then it’s time to clean your throttle body. Fortunately, our guide will teach you how to clean a throttle body easily without removing it from your car. However, if you worry about cleaning it yourself, it’s best to get a professional mechanic.