A vacuum leak produces a hissing sound when the car is running. This funky flutter sound increases as you rev the engine. The hissing sound may not be audible when the car is at idle. This is especially when the vacuum leak is small.

However, when you open the hood, you might be able to hear the sound. When driving the car, you might notice a sharp hissing sound especially given that the car is drawing more air into the engine. This is enough to cause the sound however small the leak is.

What Is A Vacuum Leak?

A vacuum leak is a situation where extra air is flowing into a combustion engine. Unfortunately, since this air gets in past the mass airflow sensor, it is not detected by the computer that measures the ideal air-fuel mixture that gets into the engine. This leads to a lean mixture that will either cause the engine to run poorly or stall. The effects of a vacuum leak are mostly felt when the engine is at idle.

Areas where a vacuum leak develop

If you want to find a vacuum leak, it is advisable to learn where a vacuum leak can occur. A vacuum leak can occur in many parts of the engine. This includes:

• Intake manifold 

This is the part that delivers air-fuel mixture into the engine. If there is a leak in this part, the injected mixture will become lean – a condition in which there are too much air and little fuel getting into the engine.

• Intake manifold gasket​

The intake manifold gasket is the tight seal between the engine and the intake manifold. If this gasket is broken, outside air will find its way into the engine.

• The throttle body​

This is the part of the intake manifold that houses the butterfly plate. This part opens and closes to regulate the amount of air getting into the engine. As a result, the car is able to accelerate and decelerate.

• Throttle body gasket​

This is a tight seal that closes up the space between the throttle body and the intake manifold. If this gasket becomes old and brittle, outside air will enter the combustion chamber.

• Vacuum hoses​

The hot environment under the bonnet may cause vacuum tubes to crack. These hoses connect to different parts of the car that depend on engine vacuum to function. Such parts include fuel pressure regulators, exhaust recirculation, and vacuum-operated actuators.

It is also important to note that

Some Engine Parts Can Fail And Cause A Vacuum Leak These Parts

Include the following:

• Exhaust Gas Recirculation Valve​

EGR valve recirculates exhaust gas back into the intake manifold in order to reduce car emissions.

• Fuel pressure regulators​

This regulator controls the pressure of fuel that is sent to the engine through fuel injectors. The regulators ensure that fuel is injected and distributed at a certain rate.

• Vacuum-operated actuators

Vacuum operated actuators use the engine vacuum to operate cruise control systems, headlights, and air conditioning. If the actuators are damaged, they may cause a vacuum leak that brings outside air into the engine.

• Brake booster​

The brake booster reduces the amount of force that the driver needs to put on the brake pedal in order to stop the vehicle. The brake booster uses vacuum from the engine to amplify the braking force that the pedal puts on the master cylinder. If this system fails, the engine may develop a vacuum leak and cannot run properly.

Symptoms Of A Vacuum Leak

When your car develops a vacuum leak, it may show some symptoms depending on the model and make of your vehicle. They include:

• Check engine light on the dashboard

• The car will have more emissions

• Decreased fuel economy. Since the car will sense more air, it will compensate by adding more fuel to the injectors thereby causing a drop in fuel economy.

• The engine idles faster and rough

• A car produces a hissing sound when running

• You get a poor acceleration

Can You Drive A Car With A Vacuum Leak?

Although it is possible to drive a car with a vacuum leak, you will have problems with an overheating engine. The heat will in turn cause hoses, plastics, and tubes to deteriorate. You should have a vacuum leak fixed as soon as possible to avoid these problems.

If the vacuum leak is in the brake booster, you should have the problem fixed immediately. This is because ineffective brakes can be very risky.

How To Prevent A Vacuum Leak

Since a vacuum leak can cause a lot of problems in your car, it is important to learn how to prevent it. Inspect your hoses and pipes regularly and if you find that they have become brittle, simply replace them.

Conclusion

A vacuum system is very important for the optimum operation of your vehicle. Understanding how it works is important for it not only determines how well your car will run but also affects other parts of the car. Vacuum leaks are a common problem. Therefore, learning how to identify a vacuum leak, how a vacuum leak sound likes, and how to prevent one is very important.