Tesla Humming Sound: Is It Normal?

You’ve always been an environmentally conscious person and have long been concerned about the emissions released by motor vehicles, and after doing the math and seeing that you will also save hundreds of dollars a year on your fuel bill as well, you finally take the plunge and invest in a Tesla. However, your shiny new electric car seems to be making funny noises.

Is the Tesla humming sound normal? The Tesla humming sound is completely normal. The humming sound comes from the main coolant pump, the fans, and the external pedestrian warning sound.

Some of the internal regulatory processes of the Tesla will cause humming, and the fact that you can hear this humming sound is more than likely a good thing as opposed to a reason to request a recall.

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Why Do Teslas Hum?

There may be a couple of reasons why your Tesla is humming, but it most likely has something to do with the main coolant pump performing its regulatory process. This regulatory process may differ depending on whether your Tesla is parked or in motion, but it mostly works to ensure that your Tesla is at the ideal temperature for functionality and longevity.

Tesla Humming While Parked

You park your Tesla and get your groceries out of the back, but just as you close the trunk and walk toward your house, you notice a noise near where the battery is located that sounds like a humming refrigerator and become concerned that something is wrong.

Fear not: What you are hearing is the main coolant pump regulating the battery temperature of the Tesla and the fans working to cool down the battery, motors, and cabin.

While lithium-ion batteries, especially those used in Teslas, are remarkably durable products capable of performing well in a variety of conditions, it is best to ensure battery shelf life, that these batteries are stored as close to room temperature as possible.

As high temperatures can lead to battery degradation over time, the coolant pump will work to keep the battery of the parked Tesla as close to 72°F (~22°C) as possible, thus creating the humming sound you hear coming from your parked car.

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Tesla Humming While Driving

If you notice your Tesla humming while in motion it is likely the external pedestrian warning sound. This pedestrian warning sound is a light humming sound in Drive, and a slightly louder humming sound in Reverse gear. When in Reverse, the humming sound gets louder as you increase speed.

Alternatively, it is once again most likely the coolant pump, which regulates the heating and cooling circuit that ensures optimal temperature of the battery and drivetrain. The drivetrain consists of the electric motor and copper rotor, which converts the direct current stored in the battery to the alternating current needed for motor function.

In particularly cold temperatures, the circuit will transfer excess heat generated from the motor to the battery. In hotter temperatures, the circuit will work to ensure that the battery stays around 110°F (~43°C), the temperature most likely to ensure the maximum battery range of the moving Tesla, roughly 373 miles (600 km) in the latest Tesla Model S.

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Why Is My Tesla Humming?

It may be concerning that your Tesla is humming, especially since Teslas have been marketed as noise-free cars. However, there are several factors to consider when you hear the humming of a Tesla:

The Tesla is doing its job. As mentioned extensively in the preceding sections, the coolant pump generates the faint humming sound to ensure the battery and drivetrain are functioning at optimal temperatures. Think of a ceiling fan gently whirring or a laptop waking up from sleep mode. All work will create at least a little noise.
The noise is exacerbated by how quiet the Tesla is. If the Tesla weren’t so extraordinarily quiet, you would never know that it made any noise at all. It’s due to the amazing efficiency of this electric car’s functionality that the humming of the coolant pump is audible to anybody.
We are used to internal combustion engines (ICE). Despite the increasing popularity of the Tesla, society is still overwhelmingly accustomed to ICE. The “roar of the engine” drowns out all other sounds of the traditional gas guzzler, and you would never notice the humming of the Tesla’s coolant pump if it were under the hood with an ICE.
We are trained to believe that “noise” equals “danger.” As a result of our familiarity with ICE, in which any noise heard above the sound of the engine would likely signal a significant issue, most people believe that “strange” noise coming from a car is a reason to be concerned and discount its role in the functionality of the designed mechanism.

Your Tesla is humming as a result of the coolant pump working to maintain optimal internal temperatures. This is a good thing and should not be met with concern.

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What if There Is Something Wrong With My Tesla?

Isn’t it so frustrating to go to the doctor, the mechanic, or the vet, describe all the symptoms surrounding an issue, and then have him or her say that it is probably this or probably that? They seem to know the answer, but don’t want to give you 100% peace of mind.

If you’re one of the people who aren’t completely satisfied that the humming sound coming from your Tesla is a simple result of the coolant pump performing its intended function, then there are several steps you can follow to help identify any underlying issues before spending significant money to have your electric car looked at by a technician:

Make a detailed note of the functionality of the Tesla. If your Tesla is and has been functioning as intended, then there is no reason at all to be concerned about the humming sound. However, if you can note or have noted anything awry, then there could be a reason for concern, and you will want to consider further investigating the humming sound
Listen to your Tesla. If you’re reading this article, you already know that it is completely normal for your Tesla to hum. Therefore, it would behoove you to familiarize yourself with this sound. The humming should be faint, so any sound that is obnoxiously loud may be a symptom of a more significant problem, perhaps an issue with the coolant pump itself
Watch videos of humming Teslas. Compare the sounds you hear against the sounds your Tesla makes when parked, plugged in, and moving, making a note of any significant changes and/or differences
Take advantage of technology – the Tesla is one of the most technologically advanced vehicles on the market. It offers an unprecedented array of gauges, monitors, and screens to keep the driver alerted to vehicle function. It is even smartphone compatible, so owners can track charge level and temperature, among other features, when they are away
Collaborate with other Tesla owners – if you are in a progressive metropolitan city, there is probably no shortage of fellow Tesla owners with whom you can share and compare your experience regarding the humming sound. If you live in a more isolated location, check out some message boards for consumers who have experienced similar concerns.

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