Rattling/Ticking from the AC Vent?

[xsilvor]

Hey y'all. I picked up my 2015 M5 last week after years of owning M3s/M4s.

Before I bought the car, I noticed an odd rattle/ticking that sounded like it was coming from around the middle AC vent when under hard (50%+ throttle). I pointed it out to the my SA, who after confirming he heard it too, told me that it's a problem with the 5s and he would have them replace the vent enclosure.

The car was in the shop for an hour or so, and afterwards I didn't hear any rattling. But, its back.

It really sounds like its coming from the AC vent area, and only under hard throttle and 4k+ rpms. It's faint enough that I don't hear it with the radio on, but I've been enjoying the sound of the V8 and don't have my radio on that much right now. I'm going to take it back to the dealership, but wanted to check to see whether anyone had a similar experience.

Thanks!

Edit: Realize I could have posted this in the general forum, but since it seems to be related to throttle/acceleration, thought this might be more appropriate.

[Spinny02]

Do you have the b&o sound system?

[xsilvor]

Nope, its the HK.

I'll add that I can't seem to make it stop by pushing on any parts of the dash, the AC vent, etc to keep it from rattling.

[xsilvor]

Another month of driving and another month of rattles and I think I finally narrowed it down to the center dash speaker cover on the HK sound system. Popped it off and took the car for a spin with no apparent rattle.

Small victory - now I need to figure out how to make sure it doesn't rattle with the cover reinstalled

[core22]

The center speaker rattling is a known issue with B&O due to the mechanical parts involved in its movement, but I've never heard about it with the HK system.

Interested to see what comes of this. Going back to the SA to show your findings?

[xsilvor]

Originally Posted by core22

The center speaker rattling is a known issue with B&O due to the mechanical parts involved in its movement, but I've never heard about it with the HK system.

Interested to see what comes of this. Going back to the SA to show your findings?

There appears to be a thin foam surround along the outer edge of the speaker compartment. I'm going to see about adding another layer of padding to see if that tightens things up. The shroud/cover itself felt like it was firmly attached... I was worried I would mar the leather trying to pry it off. If I cant fix it myself I'll take it to my SA.... Houston traffic makes me want to DIY before I give up and take it to the dealer