What is a butterfly valve used for?

What is a butterfly valve?
 

In a traditional spark-ignition gasoline engine, a throttle valve is a very important component of the air intake system. In other words, it controls the amount of air flow that enters the combustion chamber of a car engine.

As a design, the butterfly valve is relatively simple. It consists mainly of a cylindrical body, in which there is a throttle ("butterfly"), rotating around an axis, and a sensor.

Where is this valve located and how does it work?
 

Since the main task of the throttle valve is to control and control the amount of air entering the combustion chamber, there can be only one location for it - between the air filter and the intake manifold.

When the accelerator pedal is depressed, the plate in the valve opens and passes air into the combustion chamber. When the pedal is released, the plate closes and “suffocates” the air flow in the combustion chamber. The amount of fresh air that the valve enters into the combustion chamber controls the engine speed, which means that it also controls the speed of the car.

Types and operation of the throttle
 

The type of valve is determined by its design, actuator and mode of operation. Based on these factors, we can say that the types of butterfly valves are mainly two: mechanically driven and electronic.

Mechanically Operated Butterfly Valves
 

Older cars are usually equipped with butterfly valves. A characteristic feature of this operating mode is that the accelerator pedal is connected directly to the valve through a special cable.

The operating mode of a throttle with a mechanical drive is as follows:

When the accelerator pedal is depressed, a system of levers and cables is activated that open the valve. As a result, air begins to flow into the system and form a fuel-air mixture.

The more air is supplied, the more fuel is supplied, and the vehicle's speed increases. When the accelerator pedal is released, the throttle valve closes, letting in fresh air, as a result of which the engine reduces the speed of the car.

Electronic butterfly valves
 

Valves of this type are not only more modern than mechanical ones, but also have a different operating principle. Unlike mechanical valves, electronic valves do not require a mechanical connection to the accelerator pedal. Instead, they use electronic control, which allows you to fully automatically control the air flow.

Problems that most commonly occur with butterfly valves
 

Like any car element or system, the throttle valve, whether mechanical or electronic, can wear out. Fortunately, this is relatively rare, as these components are very strong and durable, and it is possible that you do not have to change the valve while driving.

However, it’s useful to know about the main symptoms that indicate that the throttle is not working properly.

Engine malfunction
Deposits build up inside the throttle body (valve) over time, which can reduce or interrupt the flow of fresh air into the combustion chamber. If this happens, the fuel and air cannot mix properly, which in turn causes an imbalance in the fuel - the air mixture and the engine will not work properly.

Carbon deposits act just like accumulated dirt. They accumulate on the walls of the throttle and disrupt the atomization of the air-fuel mixture.

Sensor problem
If the sensor located in the throttle body is damaged, it sends incorrect information to the car computer, which leads to improper mixing of air and fuel in the combustion chamber.

Low revs and idle
When the throttle is clogged or worn out, one of the most common symptoms of a malfunction is the inability to increase the speed of the car. No matter how hard you try, the speed of the car will be between 500 and 1000, and the engine will vibrate much stronger and noisier than before.

Higher fuel consumption
If fuel consumption suddenly drops and the car does not accelerate properly, this is another sign that there is a problem with the throttle.

Can the throttle valve be repaired?
 

In fact, if the valve breaks or wears out, it cannot be repaired and must be replaced with a new one. Fortunately, most of his problems can only be solved by cleaning. Manufacturers recommend cleaning the valve every 30–40 km, even if you have not noticed any of the symptoms we listed.

Cleaning is not particularly difficult, and if you have the time, desire and a few basic tools at hand, you can do it yourself.

How to clean the butterfly valve?
 

To clean the valve, you only need a special detergent, a towel and a flat-head screwdriver. If they are at your fingertips, follow these steps:

Stop the engine and locate the intake manifold hose. Follow it until you reach the bracket that connects it to the throttle
Using a screwdriver, loosen the clamp and remove the hose.
If there are other hoses, remove them.
Before spraying the valve with detergent, find out where the sensor is and be careful not to spray it.
Spray with detergent and wait a few minutes.
Connect all hoses to the throttle.
Take a test drive. Start the engine and go around the surroundings. If the valve is well cleaned, the engine should run smoothly, and the smoke coming out of the muffler should be normal.
Throttle Cleaning

If nothing changes, then you probably need to replace the valve.

How to replace a butterfly valve?
 

Tools that you will need if you decide to replace the throttle yourself: screwdrivers, rattles, a set of wrenches and pliers.

Of course, you must purchase a new butterfly valve before starting shift work. You can find out what it is by looking at the manual for your car or by asking the auto parts store where you want to buy this part.

The last thing you need is protective clothing. Usually comfortable work clothes, goggles and gloves are enough to take care of your safety.

Throttle valve replacement steps
 

• Stop the engine, locate the throttle, and disconnect all cables and hoses connected to it.
• Be sure to turn off the power and air temperature sensors.
• Deactivate throttle position sensor
• Remove all bolts that hold the throttle body
• Usually there are four of them and they attach the throttle body to the intake manifold.
• When you unscrew the bolts, you will also notice a seal. Be careful with this because you will use it when you put in a new valve.
• Remove the old butterfly valve and clean the area thoroughly.
• Install a new valve body. Make sure the seal is in place, insert the valve, tightly attach it to the intake manifold and tighten the bolts.
• Reconnect all components in reverse boot order.
• Throttle Replacement

Important. Before attempting to replace the valve as we showed you, make sure that these instructions are appropriate for your vehicle model. If you find it difficult to replace the throttle by yourself, it is better to contact a specialized service where they will perform the replacement quickly and completely professionally.

Questions and answers:

What is a butterfly valve used for? The throttle valve is part of the intake system of the vehicle. It regulates the flow of incoming air. In the classic version, it is represented by a rotary damper, adjustable by a cable.

What is the other name for the throttle valve? The throttle, the throttle valve, the throttle valve - all these are the names of the same mechanism that changes the flow area of ​​the intake tract.

What is an electronic throttle valve? In contrast to the classic throttle, the electronic throttle is electrically driven. Its position is regulated by the control unit.