Bluei3s
Posts: 18
Joined: Sun Aug 12, 2018 3:44 am

Weird AC Sound from 2018 i3s BEV

Fri Oct 08, 2021 8:39 pm

So before I start, my car is a 2018 i3s BEV with about 15k miles on it. Of course, I'm 2 months past the 3 year warranty, so there's that....now to get started.

I was driving around today on a normal 75ish degree day and had the AC on low (72ish) and I started to hear a weird sound that almost sounded like the a vent was rubbing against something. It wasn't particularly loud, but it was there. I've started/stopped the car a couple times since and the sound is still there (I just turned it on to check, but otherwise drove with the air off).

I just played with it a bit in the garage and took a few videos which are below. The video makes it sound way more aggressive than it actually is in real life, but it's definitely the right sound. The sound appears to be coming from the vents, and can be heard louder with the frunk open. It also changes volume drastically as the air is turned up and down (as you can see in the video).

Anyone know what this is? I'd prefer not to spend $20k replacing all the coolant lines....

https://vimeo.com/627018033
https://vimeo.com/627019965

alohart
Posts: 2450
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: Weird AC Sound from 2018 i3s BEV

Fri Oct 08, 2021 10:38 pm

Assuming that you reside in the U.S., is your warranty only 3 years? Our 2014 BEV had a 4-year warranty. Maybe BMW decreased the warranty length at some point.
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

Arm
Posts: 159
Joined: Tue Jan 07, 2020 5:53 pm

Re: Weird AC Sound from 2018 i3s BEV

Sat Oct 09, 2021 12:42 am

I've the same car. I don't hear anything out of the ordinary. Plus your car should have 4 year, 50k mile warranty.

Bluei3s
Posts: 18
Joined: Sun Aug 12, 2018 3:44 am

Re: Weird AC Sound from 2018 i3s BEV

Sat Oct 09, 2021 4:01 am

Ah I think you all are right, sorry about that. I must be thinking of the care plan or whatever that was only 3 years. I haven't been to a dealer since I bought it so I haven't really thought about it!

OLDBMWGUY
Posts: 21
Joined: Tue May 28, 2019 12:32 am
Location: Honolulu, Hawaii

Re: Weird AC Sound from 2018 i3s BEV

Sat Oct 09, 2021 11:34 am

Long shot: Have you checked your front inlet for the condenser? Before I installed a "grill" to protect it, I used to get leaves/debris in there and the leaves could be "sucked" up against the condenser when the A/C/Cooling system was pulling air in. Maybe that might make a noise as you describe.
Also, is it possible that one of the horizontal plastic "vanes" in there that flap up and down for temperature control might be bent/misaligned and responsible?
2019 i3 BEV, Capparis White, Tera World, Harmon Kardon Audio System, 19 inch 429 wheels

Bluei3s
Posts: 18
Joined: Sun Aug 12, 2018 3:44 am

Re: Weird AC Sound from 2018 i3s BEV

Sat Oct 09, 2021 12:58 pm

Good question, I basically looked everywhere I could see without taking any parts off. The front inlet looked clear, but I was incredibly surprised by how open it is. I replaced my cabin air filters about 6 months ago and they were pretty clean, so I'm not sure how debris stays out of there.

Did you take the screen off and just stick your arm down the intake pipe? I looked at taking the grate off, but those bolt covers looked like something that would easily snap so I just took it to the dealer for a warranty look instead.

Arm
Posts: 159
Joined: Tue Jan 07, 2020 5:53 pm

Re: Weird AC Sound from 2018 i3s BEV

Sat Oct 09, 2021 5:29 pm

Bluei3s wrote:
Sat Oct 09, 2021 12:58 pm
Good question, I basically looked everywhere I could see without taking any parts off. The front inlet looked clear, but I was incredibly surprised by how open it is. I replaced my cabin air filters about 6 months ago and they were pretty clean, so I'm not sure how debris stays out of there.

Did you take the screen off and just stick your arm down the intake pipe? I looked at taking the grate off, but those bolt covers looked like something that would easily snap so I just took it to the dealer for a warranty look instead.
What sound are you describing? From your videos, I honestly don't hear anything out of the ordinary. Are you talking about a squeaking type sound? Does it do it while the system is running? When you turn it off? When you turn it on? Etc?

I had my heater core and vent assembly replaced on a previous i3s (2019) because at start-up, I would hear a squeaking sound that coincided with the vent flaps internally moving to a different position or the fan spooling up. My 2018 i3s has a very subtle squeak coming on as well so it may need the same work done..hopefully prior to warranty end. But I didn't hear anything like that in your videos.

Bluei3s
Posts: 18
Joined: Sun Aug 12, 2018 3:44 am

Re: Weird AC Sound from 2018 i3s BEV

Sat Oct 09, 2021 5:42 pm

It honestly sounds like one of those little foam fans when you stick your finger in it. That's why I almost think it's a leaf or something stuck in the system somewhere.

The volume/severity is directly correlated to the speed of the fan, so if I turn it off, it goes away, but if I turn it up to Max it gets a lot louder (especially in the frunk area).

I'm definitely used to all the songs of the car (I bought it new), but this is absolutely a new one that both me and my wife got nervous about. The service tech also noticed it pretty quickly.

Arm
Posts: 159
Joined: Tue Jan 07, 2020 5:53 pm

Re: Weird AC Sound from 2018 i3s BEV

Sat Oct 09, 2021 6:18 pm

Bluei3s wrote:
Sat Oct 09, 2021 5:42 pm
It honestly sounds like one of those little foam fans when you stick your finger in it. That's why I almost think it's a leaf or something stuck in the system somewhere.

The volume/severity is directly correlated to the speed of the fan, so if I turn it off, it goes away, but if I turn it up to Max it gets a lot louder (especially in the frunk area).

I'm definitely used to all the songs of the car (I bought it new), but this is absolutely a new one that both me and my wife got nervous about. The service tech also noticed it pretty quickly.
Interesting...I didn't hear anything like that in your videos.

Bluei3s
Posts: 18
Joined: Sun Aug 12, 2018 3:44 am

Re: Weird AC Sound from 2018 i3s BEV

Sat Oct 09, 2021 7:33 pm

Yeah the sound of the airflow almost drowns it out using a phone mic. Someone just sent me the below link which is the exact same sound. Given how similar it sounds, I'd guess that it's a bad fan bearing. I'll wait for the dealer (obviously), but now I feel better thinking it's not a leaf!

https://m.youtube.com/watch?v=X1L2b2CDkCc

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