• Function
• Working
• Location
• Components
• Problems
• FAQs

Whether it’s about revving power or fuel economy, cars with combustion engines rely on many critical components to perform optimally. One of the tiny yet most significant engine parts is the throttle body. From controlling the circulation of air in the engine to optimising the amount of fuel burnt, it has many crucial functions.

Let’s delve into the basics of a car throttle body, its function, common problems, and maintenance.

Throttle Body Function

The throttle body is a butterfly valve that regulates the amount of air entering the engine. Its function is to maintain the air-to-fuel ratio for combustion with the help of a fuel injection system. An efficient air filter is essential for the proper functioning of a throttle body.

How Throttle Body Works

The throttle body works with the accelerator pedal. When you press the accelerator pedal, the throttle shaft rotates, which opens the butterfly valve. This allows more air to enter the engine. Similarly, when the accelerator pedal is released, the throttle shaft rotates back, which closes the butterfly valve. This restricts the amount of air that enters the engine.

The throttle body also plays a role in maintaining a stable idle speed otherwise the vehicle vibrates when idling. It can slightly open the throttle plate to allow a small amount of air into the engine, preventing stalling. Here are some of the key reasons why a car’s engine keeps stalling. 

Where is Throttle Body Located

The exact location of the throttle body may vary depending on the make and model of the car. That said, there is a consistent placement pattern. The best way to locate it is to follow the air intake system from the air filter housing. The throttle body is typically attached directly to the engine’s intake manifold.

Components of a Throttle Body

The throttle body in a car’s engine performs its crucial functions with the help of the following components. 

Throttle Plate

The throttle plate is a flat, circular or oval-shaped disc positioned inside the throttle body. Connected to the throttle shaft, its position can be controlled electronically or mechanically. The throttle plate opens and closes to control the amount of air entering the engine.

Throttle Shaft 

The throttle shaft is the rod or spindle that connects the throttle plate to the actuation mechanism. It can either be connected to the accelerator pedal cable or an electronic motor. A throttle shaft is responsible for precise control of the throttle plate’s position.

Housing

The throttle body housing is the outer casing that houses the throttle plate and other internal components. It is typically made of metal or plastic and is designed to withstand the heat and vibrations in the engine bay.

Idle Air Control Valve

In some cases, throttle bodies have an idle air control valve (IACV). This valve allows a small amount of air to bypass the closed throttle plate, maintaining a stable idle speed.

Throttle Position Sensor

The throttle position sensor or TPS is mounted on the throttle body and monitors the position of the throttle plate. It sends signals to the engine control unit (ECU) to provide information about throttle position, which is crucial for fuel injection and engine management.

Gaskets and Seals

These components are used to create a tight seal between the throttle body and other crucial intake system components. Gaskets and seals prevent air leaks that could disrupt engine performance. To learn more about the types of gaskets in a car engine, read here.

Mounting Bolts

Throttle bodies are typically secured to the intake manifold or engine with mounting bolts or screws.

Signs of a Bad Throttle Body

Since the car throttle body directly impacts the performance and fuel efficiency, the signs of it going bad are quite prominent. Here are a few common things to look out for.

Check Engine Light

One of the first few bad throttle body symptoms is check engine light. As soon as the problem occurs with throttle signals sent out by TPS, check engine light illuminates. Make sure you’re aware of all the reasons why the check engine light is on.

Rough or Uneven Idle

When the throttle body is malfunctioning, it is unable to maintain a consistent airflow when idling. This can be one of the reasons for rough or uneven idle, where the engine revs up and down erratically.

Poor Throttle Response

Carbon deposits in the engine cause the throttle plate to become stuck in the closed position, This results in delayed or erratic throttle response when the driver presses the accelerator pedal. In case of experiencing a poor throttle response, also check for these symptoms of bad throttle positioning sensors.

Strange Noises 

Sometimes, a faulty throttle body can produce unusual noises, such as hissing, whistling, or clicking sounds. Never ignore these types of car noises and sounds should never be ignored. They can indicate air leaks or mechanical issues, which should be promptly addressed. 

Difficulty Starting

Difficulty in engine starting is also among the common bad throttle body symptoms. It is due to the insufficiency of air in the combustion chamber, which hinders or delays the ignition.

FAQs

When to clean the throttle body?

A regularly maintained throttle body performs well and is less prone to the aforementioned symptoms. On average, it is recommended to clean the throttle body every 120,000 kilometres. However, it is preferable to refer to the car owner’s manual for necessary instructions.

Can I use carb cleaner to clean the throttle body?

For throttle body cleaning, it is recommended to only use a throttle body cleaner formulated specifically for the purpose. It is better not to experiment with different types of cleaners for temporary convenience. However, make sure to follow these steps for DIY throttle body cleaning.

Can throttle body cause rough idle?

Yes, rough idle is one of the prominent signs of a bad throttle body. However, if you can’t let the carbon deposits build up on it, the throttle body will keep performing optimally. Preventing rough idle is among the key benefits of throttle body cleaning.

This was everything you should know about the throttle body and its functioning. To know about your car, it is important to be aware of all the important engine parts and how they work. 

While buying a used car in the UAE, check all the crucial engine components among other inspections. Note that the mechanical components may also vary according to the engine layout type. 

To know your car better, stay connected with the dubizzle Cars blog.