Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.

Vibration/bump and clunk noise every 18 seconds with AC running?

I was told by a service center technician that it is normal to feel a slight vibration (enough for me to look out my rear view mirror to see if a person bumped/nudged my car the first time I felt it) and a low clunk noise that goes with it every 18 seconds with the air conditioning setting on? It's less frequent on cooler days, and most noticeable when the car is not being driven. It immediately stops doing it as soon as I turn the AC off, but could it be something that powers the AC and not the AC system itself?

It feels/sounds like it might be coming from behind my seat, but I will try to narrow it down tomorrow by turning on the AC from outside my car.

Any insights or experience anyone could share would be much appreciated, thank you!


Well-Known Member
May 3, 2017
While I agree with it being the compressor cycling, it likely should not be cycling at 18 second intervals. An ICE car leaves the compressor on 100% when in use. A Tesla has a variable speed compressor which should ramp up and down.
If it is cutting in or out noticeably, the AC system make be low on refrigerant and triggering the low pressure limit cut off (same as an ICE). There could also be an issue with the compressor or its control electronics.

Big Earl

Supporting Member
Jul 12, 2017
La Conner, WA
My compressor started making a bump and a loud whirring noise when it cycled off. Tesla technician took a look (I demonstrated it by opening the hood and turning the climate control on and off from the app) and said it's definitely not normal. They replaced the compressor under warranty and the problem hasn't come back.

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.