Driving an electric vehicle is unlike driving a gas-powered car.
There are unique sounds to grow accustomed to as you drive and even when you park. A Tesla is known to make a humming sound when it is parked.
While it can be unnerving to start, there’s a perfectly reasonable explanation for the sound.
What is the Humming Sound Made by a Tesla?
The “humming” sound a Tesla will make when parked is the main coolant pump at work. This is designed to keep the battery in optimum health so that it doesn’t overheat. The pump restores the ambient temperature of the battery to prolong its life and ensure it works properly.
How Can I Make Sure It’s the Coolant Pump?
When your Tesla is in park, you will hear the cooling pump working to cool the battery. The sound is often described as a soft “hum.”
Unlike gas-powered cars, there is no engine. Instead, there’s a lithium-ion battery pack that powers the motor for the Tesla. Batteries need to regulate their temperatures similarly to an engine.
If the battery overheats, it can lead to performance problems. Over time, it can also lead to degradation. When this happens, you won’t be able to get the same range you once were with your battery.
The optimum temperature for the Tesla’s battery is around 72 degrees.
Depending on how long you were driving the Tesla and how hot it is outside, it can take quite a bit of time for the battery to reach the optimum ambient temperature. As such, you’ll hear the humming of the coolant pump.
The humming shouldn’t be constant, so pay attention to how long you hear the humming for. Think of it as what you hear when you turn off a gas-powered car. Fans turn on for a few minutes to cool the engine down. After a certain amount of time has passed, the engines power themselves off. The same is true of the coolant pump.
If the hum is louder than normal or goes on for longer, it may be something other than the coolant pump. It may even signal that there is a problem with the coolant pump.
Take advantage of the Tesla services that are under warranty. Make an appointment at a Tesla service center so that you can have the sound checked out.
This way, if there is a problem, you can get it fixed before it has the chance to create further damage.
As you drive your Tesla, you’ll begin to familiarize yourself with the various sounds and hums that are made at different times. If there’s ever a sound that is out of the ordinary, have it checked out.
How Much Noise is Normal “Tesla Behavior?”
There are quite a few sounds that are “normal” when you drive a Tesla. The sooner you understand what each noise is, the sooner you’ll feel relaxed about maintaining your Tesla.
Most of the sounds are focused on temperature regulation.
If you hear humming, whirring, or whooshing sounds while you’re parked, it is likely the cooling of the battery. Most of these sounds will be heard from the front of the vehicle, even if it isn’t being charged.
If you hear the same sounds, whether it is parked or in drive mode, it is likely the A/C compressor cooling off the cabin. Especially if it’s particularly hot outside, there may be a greater demand on the climate system. As the optimal temperature is reached, the sound should gradually decrease.
If you hear a click, clunk, or thump that sounds like it’s coming from the floor of the vehicle, many of the models will open the HV battery contactors as a way to conserve energy. Once the vehicle is started after being in park, the sounds tell you that the contactors are closed.
When you’re driving, there may be a vibration sound that tells you that you have unintentionally crossed a lane as part of the Lane Departure Warning. If there’s a whirring or whining when you’re traveling at a low speed, it is actually to alert nearby passengers that the vehicle is in motion.
Creaking sound from brake calipers
Finally, another noise you might hear that is perfectly normal is when you have been in park-mode for an extended period of time.
There will be a creak or a crank from the tires/brakes that is the brake calipers releasing the rotors. Especially if it’s cold or it has been raining, the sound can be quite loud.
When Should the Humming Sound Stop?
The humming may sound when you’re driving as well as when it’s stopped. In many instances, the humming will only continue for a few minutes. The moment that the optimum temperature is reached, the cooling pump has done its job and turns off. This is designed to provide maximum efficiency.
The humming will depend on extreme temperatures, whether it be hot or cold. The hotter or colder it is, the longer the humming will continue.
It’s important to remember that there is an entire process going on.
Especially in colder temperatures, there are heating and cooling circuits that transfer the excess heat that is generated inside of the motor and the copper rotor. Once this heat is transferred to the battery, the coolant pump will begin using the innovative liquid cooling process.
Tesla utilizes a liquid coolant system that is more efficient than many of the air cooling systems utilized by other electric vehicles. As such, a Tesla can create different/longer sounds than other EVs on the market.
Typically, the noise will stop in 5 to 10 minutes. In some instances, it can take up to 30 minutes for the noise to stop entirely.
What Sounds are Normal for a Parked Tesla?
A Tesla, when parked, will only make a few sounds. If you are in a crowded parking lot or garage, you may not even hear some of the sounds. What you do hear only seems loud because the Tesla is so quiet throughout its operation.
Once the car is in park, you’ll hear a hum that is the sound of the coolant system.
Some say that it sounds like an efficient lawn mower while others believe it is much quieter. What you hear will depend on the model year of your Tesla as well as how hard the system has to work to cool the battery.
You won’t hear the sounds of an engine or gears cranking like you would with a gas-powered car.
What you may hear beyond the sound of the cooling, when the Tesla is parked, are the brakes. Disc brakes are used to hold the wheels in place. You’ll hear the calipers clicking in place on the rotors.
The humming sound is perfectly normal for your Tesla regardless of whether it is in park or it is being driven. The sound is almost always the cooling system, but there may be other sounds that you haven’t become familiar with.
If a sound goes on for too long, is too loud, or seems to be coming from a different part of your Tesla, open an engineering concern with your local Tesla service center.