Hybrid cars (powered by electricity and gasoline) that perform too well are considered “dangerous” by many people. There is an opinion that these hybrids need to be a bit “noisier.” To address this issue, many countries have requirements regarding hybrid car noise. Specifically, both hybrid and plug-in hybrid vehicles must make noise when driving at low speeds (<30 km/h) to ensure pedestrian safety.
Equipped with a sound emission system, we sometimes still hear the strange noise of hybrid cars and wonder if it’s just a normal hybrid sound or if something has happened to your car? To better understand the issue, let’s read the article below.
The reason why hybrid car noise is so strange.
The hybrid brake is damaged.
Like any other conventional car, the working principle of the brake is that when the driver wants to stop or slow down, the driver must apply sufficient braking force to make the wheels turn slowly or stop completely. But in the process, the car’s brake has shown signs of failure. One of the most obvious signs is noise during braking. What causes this phenomenon? The reasons can be:
- Worn brake pads: If the brake pads are used for a long time, the rear metal surface will slowly wear out. This causes the metals to collide with each other and create noise.
- Torn pads: A torn pad will create conditions for parts of the braking system to be exposed to each other, such as rotors.
- Bad brake discs: Worn brake discs are the cause of the annoying noise from the braking system. Brake discs that are no longer flat will produce a strange noise.
Automated gearbox failure
Electric vehicles and hybrid vehicles often use direct or automatic transmissions. When the hybrid gearbox is damaged, you can hear obvious sounds like clunking noises, vibrations, and metal clanking.
Some causes that can be mentioned are improper use of the automatic transmission such as carrying heavy loads, often driving on rough roads, shifting gears when the car is at high speed, or before coming to a complete stop… All these mistakes cause the engine to overheat, making it difficult to shift gears.
Additionally, other reasons can be listed: worn gearbox, damaged wheel bearings, or continuously driving a car under difficult conditions. If the pump shaft or the machine is faulty, you may hear a humming sound.
A hybrid engine has a problem
As you know, unlike diesel and gasoline engines, hybrid engines produce much less noise. The HEV engine is composed of energy and gasoline from the battery. Although it is much quieter, drivers will sometimes hear strange noises: squealing, tapping, clicking, knocking… from the car’s engine and it may worry you. The causes are a dirty air filter, a damaged spark plug or spark plug wire, a clogged fuel filter, or a catalytic converter.
Type of hybrid car sounds
Does any noise emitted by a hybrid car mean your car has a problem? The answer is “No.” There are many types of hybrid car noises, which can easily confuse you about the condition of your car “Is one of the car parts damaged?” Below, we will cover some types of good noises, you don’t have to worry when you hear them:
- When the hybrid engine stops, the cooling system pumps hot coolant into the thermos tank, you can actually hear the pump buzzing for a few seconds while it fills the thermos tank.
- If you are driving at low speed, you hear a strange noise and wonder: what happened to my hybrid car? In this situation, your car is completely normal. Specifically, the Acoustic Vehicle Alerting System (AVAS) of electric and hybrid vehicles must emit a clear and continuous sound when the car is traveling at a speed below 19 km/h so that pedestrians know the car is moving. The volume of this system is allowed to vary from 56 to 75 decibels (similar to an indoor conversation or an electric toothbrush). The noise of the emitted sound will increase when the car accelerates.
- The only noise that electric vehicles tend to make is the noise made by the tires or created by wind resistance, and this only occurs at higher speeds.
FQA
Why does the Toyota Prius make a loud engine noise?
The Toyota Prius is the world’s first mass-produced hybrid (gasoline-electric) vehicle. At the same time, it is also a popular car model due to its fuel economy advantages and environmental friendliness. But there are some complaints about the noise of this car. The problems can range from a simple dirty spark plug to a more serious damaged muffler or catalytic converter.
Do hybrid cars need to be charged?
With a full hybrid or a mild hybrid, the car does not need to be charged because the internal combustion engine will take on both the driving role and provide energy to the hybrid battery. As for plug-in hybrid cars, the battery must be charged by an external power source.
How to maintain a hybrid battery?
Basically, the battery does not require periodic maintenance; the part that needs periodic maintenance is the air filter of the cooling system. This air filter should be cleaned every 10,000 km and replaced every 30,000 km.