jdgamble

Hey all,

I just picked up a 2020 GLS450 over the weekend for the wife. She is very excited. So am I... such a beautiful ride.

BUT - When the AC is on a mid to high airflow setting, it sounds like there is a vacuum cleaner behind the dashboard. It's super loud and annoying. I have an appt for the dealer to fix it, but I'm curious... this cannot be normal, right? Is anyone else experiencing this?

Thanks, and looking forward to learning and contributing on this forum.

WI11C4S

I had the same concern and found that the sound was caused by the 3rd row AC inadvertently being on full blast while the front row AC was set to 3 or 4. It made the same vacuum cleaner sound you are describing. As soon as I turned off the 3rd row AC the sound went away, so I would try that before taking it into the dealer. This worked for my car with 5 zone climate which might be different from a car with 3 or 4 zone, however.

jdgamble

Yeah I don’t have the 5 zone climate control. Just the standard version. I’ve played with every vent, and no dice. It’s crazy loud. My wife noticed, and she doesn’t notice much about cars.

SteveE400

I find that sometimes if you have one or more of the vents throttled down to less than full flow output, the vent itself makes more "wind noise." Maybe you're hearing air flow noise, rather than actual blower noise?

jdgamble

So it’s a known issue. They have to take apart the dash board on my brand new car. Very excited about that. 😢

chassis

More than likely this is a Mercedes "feature". The joke is that Mercedes fan speed settings are

LO
LO
LO
LO
LO
LO
FULL BLAST

However, it's not a joke.

The duct/register whistling is also an MB feature, I have it on the center console rear duct/register of my W166. Never had it on a Ford, BMW, Toyota, Honda or Volkswagen. Only Mercedes.

R Al Shamsi

It happen to me in the agency they fixed it to me immediately, just press on AC from the touch screen, after that you will see the first row setting press on all setting once after that deselect that vacum fan from front screen after that it will be fine, also don't forget to synchronize so in the sec row if they change they just press synchronize and it will become normal again

Sadly there is no child lock for the sec and third row AC setting only for the notepad

Dave Stough

JD Gamble, did you ever get this resolved?

jdgamble

Yup. The dealer had to pull apart my dash and replace the fan. All good now. Nice and quiet.

Paxfobiscum

Is there some sort of Service Bulletin related to this?
I noticed this too. Even at the lowest fan setting, my aircon blower is loud. Its basically not because it blows a lot of air (because it does not), its just loud.
I even turned off both the 2nd and 3rd row vents, and the sound from the front vents is STILL LOUD.

jdgamble

They didn't mention a TSB. I showed it to them and they fixed it. It wasn't at low setting though... only high fan. Then it literally sounded like a vacuum cleaner.

AK-21GLS450

any noises from the dash after they took it apart? That makes me nervous but have the same issue.

jdgamble

No. It was fine after the fix. But I got rid of the car about a year ago cuz things just failed way too often.