Annoying popping plastic noise out of my dash driving me crazy!

[TMR013]

Originally Posted by bobbydm

I take your point entirely, it does sound more like plastic changing shape with temperature change but it would be great to rule out the issue with the strut! The only basic explanation of the popping whilst the car is sat still is that the strut is also changing shape with temperature. I wonder how close the AC vents are to the strut fitting?

Would be great to have a good diagram... I hope mine doesn't start popping soon! It would be interesting to see if it happens to cars with a certain milage or age? All I do know is, I hate random noises like this in cars

Mine started almost immediatly. The first time I used the AC.
Don't think it's the strut, if it is, why would it only happen when AC is running.
Really guys, you will get used to it and tune it out, I barely notice it anymore.

[N55_BBM]

Got my car in July of last year. Never noticed it til this May though. Why it didn't happen last summer? no idea...

I've had the noise for 2 months and it still annoys the hell out of me. If it were a ford focus I wouldn't give a rat's ass, but it's really embarrassing when I have friends riding in my BMW and they go "what the f is this terrible pop?"

[davefromfla]

Still have not had it in my 2011 135 delivered in November 2010. I was sort of expecting it from what I saw in the forum, especially being in central Florida (where it has been very hot).

[opvaulet]

Pop sound comes from the contact between the A pillar trim and the dash when the car structure twists, especially in hot weather. To confirm try and squeeze a large size cable tie (black in color) between the gap. Noise should disappear.

[RPM90]

Originally Posted by bobbydm

This actually makes sense to me! I had the exact same problem on a BMW Z4 about a year ago. Popped when pulling of my driver, braking over bumps, accelerating and sometimes randomly. After trying everything behind the dashboard I searched some forums. I was advise to tighten the strut bars pictured below. When trying the top (boxed in yellow) strut fitting, the bolts where a bit loose.

After tightening all fittings, the popping stopped.

I have just checked the 135 and the top ones are very hard to get to. If I get the popping noise it will be the first thing I try. Has anyone managed to do this to rule it out?

My theory is that they are right behind the dashboard and will loosen over time, this causes the bars to knock/pop when the cars flex. Worked on the Z4 which had the exact same design.

That is my suspicion too. There have been a few other threads about this issue, but it didn't seem likely that it was HVAC heat//AC related as the sound described is really loud. I doubt plastic would make that sound.
I recommended that someone have their dealer re-torque the strut top mounts and the strut tower bars.

I can see this sound happening more when the temps get hotter as it may be related to the different metals that are used for the strut, bar, and connection points. These metals may have different heat/cold expansion and contraction levels, so when the conditions are right some metal may expand quicker than the other and that results in a loud pop or bang.

It's possible that during assembly proper torque was not applied, and/or torque has loosened over time and with heat and cold cylces.
Just an idea, but it's worth a shot to get it to stop.

Your experience points to a potential fix.

[RPM90]

Originally Posted by opvaulet

Pop sound comes from the contact between the A pillar trim and the dash when the car structure twists, especially in hot weather. To confirm try and squeeze a large size cable tie (black in color) between the gap. Noise should disappear.

Interesting.

You're suggesting to insert a thick cable tie between the A pillar and dash, right?
I don't have this problem in my car, or at least not to the level that some describe. I have heard a slight "tap", which sounds like it's coming from my upper glove box area, but it's very slight and happens in warmer weather with AC on or off. But again, nothing like a loud bang, or a rock hitting my windshield.

For those who have this issue it seems like an easy thing to try.
Post up once you've tried it.

UPDATE:
I checked that area and I don't see how that can be causing a loud sound. The A pillar cover is covered by cloth like material and that piece has a lot of easy flex to it. If it needed to expand there is plenty of play in it that it could easily do it with no effect. Maybe I'm missing something?

[RPM90]

Originally Posted by jainism

My 2011 135i with 2800 miles on it just started doing the "pop". Its from the Air conditioner....The noise is right above the glove compartment. Its the vents popping open to change from circulate to non circulate air.. It only happens when i put my A/C on 'Auto Recirculate'. You guys are looking too deeply in to this. My Mercedes did the same thing.

If that's true then there is a lot of build quality variance cause a lot of us don't have this sound, and some don't have that loud of a sound.

But then some may be experiencing different issues.
Describing a loud "pop" or "bang" doesn't point to only one thing, as these sounds may be created by different issues.

In my case I've never heard the circ/recirc valve make any sound like a pop or a bang. I barely hear it closing and opening at all.

[Rawhide]

My '08 128 Convertible was plagued by all sorts of popping and clicking sounds in the cab, but only on really cold mornings as my car heated up.

My 135 with 17k miles has never made a sound.

Someone mentioned the sinking of the dash around the airbag. My 135 is starting to display this under the right lighting conditions - is this a warranty repair?

[ski747]

Dealer advised me that it was the AC vents contracting in the heat, etc. If you read my other posts, mine has the same characteristics, but it is so loud it sounds as if someone threw a rock or brick at the car. Very loud over the radio and AC. I can even be sitting and I hot the AC it comes from the right side of dash. They have torn everything out and no change in sound. Sometimes I think the dash is falling off it is so loud. May sound extreme but it is extremely loud. I am going to try putting the piece between the dash/pillar and then check the bolts. BMW rep even looked at it and said normal??? Blew my mind. Mine is not a sound I can get used to or tune it out. Sound is way too loud to ignore.

[ski747]

Originally Posted by RPM90

That is my suspicion too. There have been a few other threads about this issue, but it didn't seem likely that it was HVAC heat//AC related as the sound described is really loud. I doubt plastic would make that sound.
I recommended that someone have their dealer re-torque the strut top mounts and the strut tower bars.

I can see this sound happening more when the temps get hotter as it may be related to the different metals that are used for the strut, bar, and connection points. These metals may have different heat/cold expansion and contraction levels, so when the conditions are right some metal may expand quicker than the other and that results in a loud pop or bang.

It's possible that during assembly proper torque was not applied, and/or torque has loosened over time and with heat and cold cylces.
Just an idea, but it's worth a shot to get it to stop.

Your experience points to a potential fix.

I am going to try this. Makes perfect sense!! Excellent idea!! Thanks!

[RoundelM3]

2011 128i Cabrio here with 100+ degree weather, no popping thus far...

[Sylon]

Driving with the air on and the windows down gives me a better chance at hearing the pop then any other time. I prefer to drive with my windows down, and I usually dont hear it. Its when I have the air on and the windows down (to cool off the cabin faster), I usually hear it every time.

[N55_BBM]

UPDATE:

Car's at the dealership and with this lovely 95 degree weather the service technician has been able to duplicate the noise. He's taking the car apart little by little and retesting to see if it still pops because the source of the popping in the dash is "inconclusive".

I told him about the strut bar over the engine, he did tighten it up but it still pops so it wasn't the issue. Just thought I'd give you all an update as far as this goes....

[DriveHard]

Originally Posted by N55_BBM

UPDATE:

Car's at the dealership and with this lovely 95 degree weather the service technician has been able to duplicate the noise. He's taking the car apart little by little and retesting to see if it still pops because the source of the popping in the dash is "inconclusive".

I told him about the strut bar over the engine, he did tighten it up but it still pops so it wasn't the issue. Just thought I'd give you all an update as far as this goes....

Hey Bru... look at you.. Finally an answer to your issue.. Im glad they hear it ( doesnt mean they can fix it LOL ) but glad they hear it..

Did all the looking i could, and although there are those on the forum with same / similar noises there is nothing in regards to a TSB or anything as discussed earlier.

odly enough, sometimes just taking this apart and putting them back together "fixes" noises...

when you get your car back, take a peek at all the trim and dash panels for damage / fit and finish.. all that stuff pry's out to get off.. vents / wood trim / etc etc

keep us informed !!

[N55_BBM]

Just wanted to follow up (or provide some closure rather)

Mine got fixed . Dealership detected the noise, tore the whole dash apart, and then put it back piece by piece while testing. 90 degree weather helped out. They couldn't determine what was causing the noise but they put in a bunch of insulating felt strips (didn't quite understand what that is). Anyway, noise is gone and I'm happy now . Took a week for them to do this

[DriveHard]

Originally Posted by N55_BBM

Just wanted to follow up (or provide some closure rather)

Mine got fixed . Dealership detected the noise, tore the whole dash apart, and then put it back piece by piece while testing. 90 degree weather helped out. They couldn't determine what was causing the noise but they put in a bunch of insulating felt strips (didn't quite understand what that is). Anyway, noise is gone and I'm happy now . Took a week for them to do this

INSULATING FELT TAPE = soft selfadhesive fluffy tape, as in the soft part of velcor but just much thinner..

works wonders

[TMR013]

Originally Posted by N55_BBM

Just wanted to follow up (or provide some closure rather)

Mine got fixed . Dealership detected the noise, tore the whole dash apart, and then put it back piece by piece while testing. 90 degree weather helped out. They couldn't determine what was causing the noise but they put in a bunch of insulating felt strips (didn't quite understand what that is). Anyway, noise is gone and I'm happy now . Took a week for them to do this

Honestly tearing the dash apart would scare me to death with the thought of increased rattles and other noises. Hope the gamble works out for you.

[N55_BBM]

Originally Posted by TMR013

Honestly tearing the dash apart would scare me to death with the thought of increased rattles and other noises. Hope the gamble works out for you.

well it did fix it. and i wouldn't call it a gamble. think about it this way: the dash as was made a god awful popping sound, couldn't get any worse and i couldn't stand it. BMW gives me a sweet loaner every time I drop my car off (got a fully loaded 335d with m-sport last time). they keep my car until it's absolutely fixed. if they were to scratch something or damage the finish, they'd replace it. the more time it takes them, the more i save with wearing my own tires and mileage depreciation. i get the car with a full tank of gas and return it empty with no questions asked. and all of this costs me $0. hardly a gamble, really.

[Viper_iii]

2010 Vert 128i all sorts of noises in the dash...

however not worried as they can't seem to get the check engine lights problems solved...

July alone it has spent ~ 2 weeks in the shop...

Replaced VVT / VTT Revved while parked + AC in 100+ Degrees then shook as idle went down and threw error code.

3 days out of shop if that Starting acting like it wasn't getting fuel... soon there after "service engine soon" came on... Had just had all service done oil + brakes
Ended up replacing HPFuel Pump + Fuel Regulator in Gas tank...

3 days out of that repair...
Sitting in the car and again it Revvs idles hard... throws Check Engine Light

At this point... I'm done with the car... The rattles are without a doubt the dash positioning and rubbing with other plastic / components against the passenger pillar / area. can replicate by pushing the dash up... and it got worse after they dropped the dash on the 1st repair.

How about on the convertibles the twang sound that happens when hitting a bump / driveway at low speed 2-8 mph... that one is also great....

currently also noticed MPG's going downhill much worse.... ~160miles to a tank of 91 octane vs low 200s over the past 36 months.

All I can say is glad it was a lease, and my only expense thus far has been Cheap Non-RFs

[gnpower]

Have they cleaned the intake for over build up of carbon deposits? Mine was idling rough and lost some power until they cleaned it and it runs like new again.

Originally Posted by Viper_iii

2010 Vert 128i all sorts of noises in the dash...

however not worried as they can't seem to get the check engine lights problems solved...

July alone it has spent ~ 2 weeks in the shop...

Replaced VVT / VTT Revved while parked + AC in 100+ Degrees then shook as idle went down and threw error code.

3 days out of shop if that Starting acting like it wasn't getting fuel... soon there after "service engine soon" came on... Had just had all service done oil + brakes
Ended up replacing HPFuel Pump + Fuel Regulator in Gas tank...

3 days out of that repair...
Sitting in the car and again it Revvs idles hard... throws Check Engine Light

At this point... I'm done with the car... The rattles are without a doubt the dash positioning and rubbing with other plastic / components against the passenger pillar / area. can replicate by pushing the dash up... and it got worse after they dropped the dash on the 1st repair.

How about on the convertibles the twang sound that happens when hitting a bump / driveway at low speed 2-8 mph... that one is also great....

currently also noticed MPG's going downhill much worse.... ~160miles to a tank of 91 octane vs low 200s over the past 36 months.

All I can say is glad it was a lease, and my only expense thus far has been Cheap Non-RFs

[Chris_B]

Had a similar problem with my 08'.
Popping/imprint etc. It was a bit ago, but when I took it in they had a bulletin for replacing the dash with one with a fancy dash w/ a container in the middle. Like I said tho, that was a bit ago haha.

I would say non stop complaining to your service advisor!
I'll dig up old files see if I can find info on exactly what they did for mine. It was posted on the forums so I'll go treasure hunting!

[Lloyd]

I get this every once in awhile in my 2010 135i. Glad I found this thread, I thought I was alone for a second. If its due to heat, well I live in Florida and it gets hella hot in my car this time of year. Its not a big deal to me. If it gets more prevalent before my warranty is up, I'm definately going to have BMW fix it.