Bone stock 2002 Mini Cooper S ~ 70k Miles.

Ok folks, before you tell me it's the sunroof..... let me explain. It is sunroof-related, but as far as my ear can determine, the sound isn't coming from the roof. I have a nasty rattle that sounds (to me like) thick glass rattling against metal (like a windshield loose against the frame with no seal to cushion it), but as far as I can tell it appears to be coming from either
A) Passenger (US, Left-hand drive car) footwell
B) Behind the dash passenger side
or possibly
C) Passenger mid to lower door.

The thing is, this rattle, it only happens when I am driving with the sunroof or the windows open. And its quite pronounced. Neither of my windows or sunroof seem to have any play or movement in them so far as I can tell. And when I hold my hand against the sunroof, the rattle continues and I can't seem to feel the rattle through the sunroof glass.

Now both door speakers have been junk for a while. I just finished putting a new speaker in the driver door, and fully sound deadening the entire inside of the door (1 layer of Noico Red 315mil closed-cell over 1 layer of Siless black 80mil butyl on the outermost door skin facing in, and 1 layer of kilmat reflective 80mil butyl on the metal inner door skin facing towards the outside of the car (to help reflect the radiant heat away from the interior the summer and keep it cooler while I'm driving it). I will start doing the passenger side door tomorrow but its a time-consuming PITA to do the insides of the door, especially the backside of the inner panel while trying to cut all the pieces to fit the stamping and make all the holes for the panel fasteners, etc, so you'll understand why I didn't get it all done at once. By the way, this has turned out to be amazing. One drive and I feel like I have an earplug in the ear facing the driver door yet with the other ear, I can still hear the rest of the car's creaks and rattles clear as day. Unless I've gone deaf in that ear, I think the sound deadening is working quite well

That being said, part of me wonders if the glass-on-metal sound that (I think) I am hearing isn't possibly the changing air pressure in the cabin (when either the sunroof or windows are open) rattling the blown speaker in the passenger door. But I don't think that the air pressure should be changing dramatically over bumps like that. What I don't understand, and why the air pressure thing even enters my mind, is why this only happens when the windows or sunroof are open. I could crack the sunroof open just a little and there is the rattle. Same with either window or any combination of windows and sunroof. Open the cabin to the outside air and there is the rattle. Close the cabin uptight and that rattle doesn't exist.

Any thoughts? I am also having some issues with the HVAC, the air doesn't always seem to blow where it's supposed to based on the vent setting. Mostly it seems like its always blowing hot air at my feet no matter what vent setting I use. But heat and AC both work, it just seems to be a louver/valve/baffle/diverter that's not functioning correctly. This comes back to the air pressure thing, but I don't know. I'm not looking for a solution to the heat blowing on my feet right now (one issue at a time), I'm just throwing this out there as a data point for your brains to take into account.

Any insight would be greatly appreciated as it would be amazing to enjoy the spring and summer with the windows and sunroof open, without having to cringe every time I hear that rattle, thinking something is about to shatter.

 

Given the HVAC issue and your thought that it sometimes sounds as if the sound is in the dash, it could be a loose blower motor and/or air diverter. I'm pretty sure I have a loose blower motor, though I only hear it when going over bumps and I wouldn't describe the sound as glass on metal. Can't comment on how difficult it is to fix -- I hope to dig into that this summer.

 

Place I would start, try the glove box. Might be the door has a little bit of play, when the roof is open the car could possibly flex a little bit more?

might be worth opening it while driving and see if it changes, if it does glass companies usually have little roam pads sticky on one side, stick some of those inside so when the door is closed its tight on the latch had to do exactly the same on my parcel shelf!

 

I will take it for a drive this afternoon and see what I can find. I'll try opening the glove box as well try messing with the HVAC controls to see if any of that has a noticeable effect on the sound. I don't think it's the glovebox, the sound just isn't right. The same goes for the blower motor and flapper door, but still, all good things to check. The only reason the speaker occurred to me even though I believe it sounds like glass hitting something (and I am more than willing to admit that my perception may be wrong) is simply because speakers can make all sorts of sounds and it does all sound a little bit like the pop you get from dropping the needle on a record player (though maybe higher pitch), which obviously would be heard through a speaker. My hope is that it's not some electrical short causing the speaker to "pop" when I hit a bump. I sort of doubt that though as it wouldn't seem to correlate with window/sunroof position and most shorts don't energize things, and Id think pops in a speaker would come from a burst of energy, not the reverse. We shall see though.... Any additional insight is still very much welcomed as I am guessing I won't figure this out today, regardless of what I try.
Thanks for the insight guys!

 

Nothing. Tried everything, glove box open, closed, everything out of it, different HVAC settings, different blower settings, different vent selections, recirculation vs fresh air, none of it seems to have any effect.

Everything seems to remain the same. Crack a window, either window, open then both all the way, crack the sunroof, open it all the way, any combination there of. If the cabin is open to the exterior in any way, I get the rattle. Put the windows up and close the sunroof, no rattle.

If replacing the speaker in the passenger door has no effect (and I don't expect it to), I'm pretty much left with tearing into the dash as I don't believe any of the duct controls are accessible otherwise.

Any thoughts?

 

Does it happen when there’s a passenger in the car?

 

Can you leave the passenger door card off while driving. Trying to exhaust everything before going dash issues, however the car will loose structural rigidity when a window is open. I'm not sure if the glovebox will pull out so that you can get someone to drive while you poke and prod

 

I rarely have any passengers in the car as I just use it to run back and forth to work, but I can ask the wife to go for a ride with me, another pair of ears wouldn't be a bad idea. Though I think it'll be easier to convince her while the door is still on lol.

As far as pulling the passenger door off, I might try that but I will do the speaker and sound deadening first as it has to be done anyways. I just don't have a whole lot of faith that its the speaker which is why I am asking before I've had a chance to do it. Hoping I can come up with a solution I can implement while I am doing that work. As much as I don't want to pull the dash out, (and I will see if I can fix the rattle without pulling it out if it proves to be an HVAC blend door or something like that), I do plan on pulling out the entire interior to do the rest of the sound deadening. I'd prefer not to pull the dash out too, but then I guess if I do take that on, I can at least get to everything and mitigate any other potential current or future rattles with some closed-cell foam, padding, and the like.

Thanks again guys for your insight. I'll let you know what I find over the long weekend and as always I am open to any additional thoughts.

 

I meant just the plastic door trim unclip it so you can see the window mechanism and then go for a ride. Also if someone can drive the car for you, you will be able to look for exactly what you are hearing without trying to explain to someone else.

Good luck

 

With the sunroof partially open, does applying firm upward pressure to the sunroof glass make the sound stop?

Another thing to check - one of the cables inside of the passenger door. When the window is up, the glass is far away from the power window cables. If any work was done inside that door and a cable retainer broke, you could be hearing the cable rubbing on the window when the window is partially inside of the door. Something to check. I had my passenger window replaced back in 2013 or so, and the window guy managed to really mess up a bunch of stuff. Took me years to get is all resolved, including an intermittent noise from cable rub on the window glass when partially down.

 

I had a rattle at the front edge of the dash panel where it meets the lower part of the windshield. I solved by wedging a piece of foam in the slight gap. I think the front edge of the dash panel vibrates against some structure underneath.