Single 'clunk' noise in cabin.

[m981addicts]

Has anyone experienced a single clunk while driving that happens maybe once or twice a day, and seems to emanate from inside/outside of the cabin vicinity.

It started happening a few days ago and now seems to occur at least once or twice per day, at no particular speed--it has happened at various speeds from 30 to 80 mph, usually just cruising at a constant rate, in a straight line.

The first occurrence had me thinking that a small rock bounced from a moving dump truck unto my car except that there wasn't any vehicles in both directions. The next occurrence seemed to come from the dashboard passenger side. Following that, the sound seemed to be from the headliner area. Last, it seemed to come from the driver's side under the dash.

Last night, I noticed that the headlight switch was slightly pushed into its position in the dash, as described by others on the forum who accidentally kneed it. I'm not sure if this was purely coincidental to the clunking or related.

I probably won't be able to replicate the sound on demand as there's no common symptoms of vehicle dynamics.

Anyone else experience this?

[IEDEI]

Originally Posted by m981addicts

Has anyone experienced a single clunk while driving that happens maybe once or twice a day, and seems to emanate from inside/outside of the cabin vicinity.

It started happening a few days ago and now seems to occur at least once or twice per day, at no particular speed--it has happened at various speeds from 30 to 80 mph, usually just cruising at a constant rate, in a straight line.

The first occurrence had me thinking that a small rock bounced from a moving dump truck unto my car except that there wasn't any vehicles in both directions. The next occurrence seemed to come from the dashboard passenger side. Following that, the sound seemed to be from the headliner area. Last, it seemed to come from the driver's side under the dash.

Last night, I noticed that the headlight switch was slightly pushed into its position in the dash, as described by others on the forum who accidentally kneed it. I'm not sure if this was purely coincidental to the clunking or related.

I probably won't be abled to replicate the sound on demand as there's no common symptoms of vehicle dynamics.

Anyone else experience this?

haha...i had that in my 135is....and i have it now in my 1M.

[the1andonly]

If its more of a "POP" sound from the dash area its common. Its caused but hot temps outside combined with the materials/fitment in dash. You prob didn't hear them in cooler weather.

[cvandenhaute]

Typical in summer, mine (re) started to do that

[MZWIE]

It's the AC recycle valve slamming shut.

[Worra]

Yep, happens here as well in my 135is.

[m981addicts]

ok thanks...misery loves company!

[jclaib7]

Originally Posted by m981addicts

ok thanks...misery loves company!

I was just getting ready to start a thread on this. Loud POPPING noise from glove compartment area. Happens at random and not necessarily when it's hot. It happens even when not using the AC for awhile.

It's a pretty good pop with some force behind it.

I thought it had something to do with the M3 front sway bar and springs or something.

[chris82]

My cabin makes all sorts of noises too

[m981addicts]

Originally Posted by jclaib7

I was just getting ready to start a thread on this. Loud POPPING noise from glove compartment area. Happens at random and not necessarily when it's hot. It happens even when not using the AC for awhile.

It's a pretty good pop with some force behind it.

I thought it had something to do with the M3 front sway bar and springs or something.

Same here, temperature independent--hot or cold. Funny thing is, just started happening about a week ago after a 1200 mile trip. Never happens with my 09.

[cheshirecat79]

Originally Posted by e34m5

It's the AC recycle valve slamming shut.

This is correct- but I think the proper term is the recycle flap/actuator.

You can actually see the unit when you remove your cabin air filter. It's a very large flap on the passenger side of the car located near the firewall above the glovebox. It builds up pressure (not sure if it binds or not) and will "pop" open when the recirculation mode is set to Auto.

If you don't want to hear the noise, set the recirculation to open or closed and the flap will not move and freak your passenger out when it finally unbinds and gives you that nice "my suspension spring just snapped in half" noise.

[Worra]

Originally Posted by cheshirecat79

This is correct- but I think the proper term is the recycle flap/actuator.

You can actually see the unit when you remove your cabin air filter. It's a very large flap on the passenger side of the car located near the firewall above the glovebox. It builds up pressure (not sure if it binds or not) and will "pop" open when the recirculation mode is set to Auto.

If you don't want to hear the noise, set the recirculation to open or closed and the flap will not move and freak your passenger out when it finally unbinds and gives you that nice "my suspension spring just snapped in half" noise.

Freaked me the f out the first time for sure.

[TMR013]

Trust me, you will get used to it and tune it out. I don't hear it at all anymore, even though I know it still happens.

[fcman]

Still freaks me out sometimes

[CAVU]

Originally Posted by cheshirecat79

This is correct- but I think the proper term is the recycle flap/actuator.

You can actually see the unit when you remove your cabin air filter. It's a very large flap on the passenger side of the car located near the firewall above the glovebox. It builds up pressure (not sure if it binds or not) and will "pop" open when the recirculation mode is set to Auto.

If you don't want to hear the noise, set the recirculation to open or closed and the flap will not move and freak your passenger out when it finally unbinds and gives you that nice "my suspension spring just snapped in half" noise.

Really!?!?!? If this is correct, it would be a giant relief! About 500 miles ago I started occasionally getting a loud and startling "bonk" or "crack" sound from the right side A pillar area. Sounds loud and super solid... I can feel it in the steering wheel. I've checked the strut tower hardware and braces... that's how loud and connected to the car's suspension this sound "feels".

[fcman]

Try changing the recirculation mode between on and off (maybe give it a few seconds in between) and see if it is the same sound you are hearing.

[CRuben09]

About a year ago I got this issue solved under warranty. It haven't come back since (knocking on wood).

From my post a year ago:

Item #10 claimed under warranty during my visit to the dealership. Popping sound on passenger side dashboard (this happened whenever I left the car parked at sunlight for more than 1 hour and the interior get frikin hot, when returning back with the A/C on a Pop sound will come from the dashboard every time). It is pretty uncomfortable when having people riding with me, specially the haters.

Since I live in Puerto Rico, the tropical weather is all year long. They could duplicate the issue easily, and found that it was the airbag in the passenger side dashboard. Apparently it gets loose or something and with the expansion of the heat and contraction of the cool air it made a popping noise. They fixed it, and now the sound went away. This haunted me for at least a year.

Hope this helps.

[Downeaster1]

It also happens in my 135is all the time.

[TJ710]

Wow I'm so glad this thread was started. I get the same noise in my cabin and I wasn't sure what to do about it. It's a relief to know it's normal.

[m981addicts]

Originally Posted by CRuben09

About a year ago I got this issue solved under warranty. It haven't come back since (knocking on wood).

From my post a year ago:

Item #10 claimed under warranty during my visit to the dealership. Popping sound on passenger side dashboard (this happened whenever I left the car parked at sunlight for more than 1 hour and the interior get frikin hot, when returning back with the A/C on a Pop sound will come from the dashboard every time). It is pretty uncomfortable when having people riding with me, specially the haters.

Since I live in Puerto Rico, the tropical weather is all year long. They could duplicate the issue easily, and found that it was the airbag in the passenger side dashboard. Apparently it gets loose or something and with the expansion of the heat and contraction of the cool air it made a popping noise. They fixed it, and now the sound went away. This haunted me for at least a year.

Hope this helps.

What was the fix? Drove my 09 135 for three years in sea-level tropical weather, then now makes two years in dry hot/cold 4500 ft mountains without a 'Pop.'

[CRuben09]

Originally Posted by m981addicts

What was the fix? Drove my 09 135 for three years in sea-level tropical weather, then now makes two years in dry hot/cold 4500 ft mountains without a 'Pop.'

It was the passenger side airbag. Apparently it was loose or something. When they adjusted it, the pop sound went away.

[heeblet]

Great thread - I"m going to add that to the list of items on my next service appt. To me sounds like a rock nailing the windshield. Is that a good analogy to anyone else? Loud pop.