Metallic Sounding Rattle Near Passeneger Seat
05-22-2017, 06:22 PM
#16
Instructor
Thread Starter
Hi Alan,
I just did an experiment this weekend to go after a continued rattle I have in my roof..... while not your rattle, how I found it could help you find yours.
I played sine wave sound loudly through the stereo and that shook everything and exposed the rattle! Porsche actually makes a CD with sine wave on it (thanx Wayne for triggering this idea).... I am audiophile and had test CDs with these tracks. Anyhow, you can easily download tone bands onto a USB stick or burn a CD and do the same... there are apps for you phone "tone generators" if you can interface your phone to your car.
For me, a 50HZ sine wave at decent sound level shook the **** out of the interior and exposed the vibrating panel and where it was most prevalent. Best to use a sample of 1/3 octave under say 440 HZ.... that should do it. That rattle you have has a resonance frequency that will expose it so you will have to try a few different frequencies. (BTW, I found that our Bose systems will play a decent signal down to pretty close to 20 hz!)
I made two very raw vids that am planning on turning into a descent short one...... see link below ...... what you don't hear in the vids is the booming 50hz sine wave filling the cabin as I suspect the microphone in my Motorola Force Z simply doesn't pick up frequencies that low.... but you can hear the roof buzzing away!
If the vid doesn't play, click the menu up in the top right and download them.... they should come down fast... then click on the vid from your download folder. For some reason, they don't play for me when I click on the cloud version.
Peace
Bruce in Philly
Let me know if this link works or helps:
https://goo.gl/photos/zG3KY99vDUNefhBc8
I just did an experiment this weekend to go after a continued rattle I have in my roof..... while not your rattle, how I found it could help you find yours.
I played sine wave sound loudly through the stereo and that shook everything and exposed the rattle! Porsche actually makes a CD with sine wave on it (thanx Wayne for triggering this idea).... I am audiophile and had test CDs with these tracks. Anyhow, you can easily download tone bands onto a USB stick or burn a CD and do the same... there are apps for you phone "tone generators" if you can interface your phone to your car.
For me, a 50HZ sine wave at decent sound level shook the **** out of the interior and exposed the vibrating panel and where it was most prevalent. Best to use a sample of 1/3 octave under say 440 HZ.... that should do it. That rattle you have has a resonance frequency that will expose it so you will have to try a few different frequencies. (BTW, I found that our Bose systems will play a decent signal down to pretty close to 20 hz!)
I made two very raw vids that am planning on turning into a descent short one...... see link below ...... what you don't hear in the vids is the booming 50hz sine wave filling the cabin as I suspect the microphone in my Motorola Force Z simply doesn't pick up frequencies that low.... but you can hear the roof buzzing away!
If the vid doesn't play, click the menu up in the top right and download them.... they should come down fast... then click on the vid from your download folder. For some reason, they don't play for me when I click on the cloud version.
Peace
Bruce in Philly
Let me know if this link works or helps:
https://goo.gl/photos/zG3KY99vDUNefhBc8
05-22-2017, 07:26 PM
#17
RL Community Team
Rennlist Member
Rennlist Member
Be careful what you wish for.... A 31.5hz wave discovered a buzz in each of my doors I didn't know were there.
Tips:
- Sine wave only (no square or sawtooth shape)
- Try different frequencies ..... since 50 hz worked for me, start there, random spot... say three points between octaves (440 and 220 is an octave show choose two points between...... 50 and 100 is an octave so choose two points between)..... that should do it.
- Start with low volume and then bring up... you could blow out a speaker or your ears.... but louder is better for more shaking.
- Don't go above 10,000 hz, you could hurt your hearing if the volume is too high - just keep the volume low as I know you are going to do it just because
- If you play the tones on your phone first, you may not hear anything if the frequency you are playing is above or below your phones ability to generate sound. My phone is silent at 50hz.... the speaker just can't move the air... there is a reason woofers tend to be large in size.
- Seal up the car... close the doors, windows and roof... turn off the fan.
- Make sure the car is level as not to torque the chassis.... or maybe this is required for you (?)... For me, I could not get the roof panel to buzz much when on uneven ground showing the roof is flexing.
Peace
Bruce in Philly
Tips:
- Sine wave only (no square or sawtooth shape)
- Try different frequencies ..... since 50 hz worked for me, start there, random spot... say three points between octaves (440 and 220 is an octave show choose two points between...... 50 and 100 is an octave so choose two points between)..... that should do it.
- Start with low volume and then bring up... you could blow out a speaker or your ears.... but louder is better for more shaking.
- Don't go above 10,000 hz, you could hurt your hearing if the volume is too high - just keep the volume low as I know you are going to do it just because
- If you play the tones on your phone first, you may not hear anything if the frequency you are playing is above or below your phones ability to generate sound. My phone is silent at 50hz.... the speaker just can't move the air... there is a reason woofers tend to be large in size.
- Seal up the car... close the doors, windows and roof... turn off the fan.
- Make sure the car is level as not to torque the chassis.... or maybe this is required for you (?)... For me, I could not get the roof panel to buzz much when on uneven ground showing the roof is flexing.
Peace
Bruce in Philly
Last edited by Bruce In Philly; 05-22-2017 at 07:57 PM.
05-22-2017, 11:10 PM
#18
Instructor
Thread Starter
05-25-2017, 12:08 PM
#19
Thanks Bruce for posting that info. I had been pulling my hair out trying to track down a rattle and found it using the Tone Generator (by TMSoft) iphone app. My radar detector mount was buzzing, but the main culprit was the sport chrono wart.
05-25-2017, 08:29 PM
#20
RL Community Team
Rennlist Member
Rennlist Member
Do you remember which vibration frequency got your car off? Or was it frequencies? This data may help others.
Peace
Bruce in Philly
05-26-2017, 06:30 PM
#21
Unfortunately I do not remember exactly, but the 3 rattles I found were between 50 and 70 I think. A 3rd rattle that I did not previously mention, was in the passenger side door above the arm rest, but it is so minor that road noise cancels it out, and taking the door apart is a PITA.
05-27-2017, 11:14 PM
#22
Three Wheelin'
Made me think of years ago. Walked into technicians shop at work. Two guys had t-shirt with symbol on it. I said oh, you all are the sine waves. One guy said to other see- he got it. They were trying to come up with name for softball team. Other guy ended up winning argument. Figured too esoteric for most to figure out. Told them so be the cosine's.
05-27-2017, 11:57 PM
#23
Do you have a PDK or manual. How much of the center console do you have to remove to get at the clips?
06-21-2017, 11:16 AM
#24
Instructor
Thread Starter
Just thought I would update everyone. The sound was driving me nuts.
I went through countless posts trying to nail this down and was convinced it was the same as Edgy01 had posted here --> https://rennlist.com/forums/997-foru...heel-well.html
It was not. I then took apart the whole passenger side AC vent/duct and side panel that meets the door. The duct was loose but it was all plastic and did not look like it would be making the same noise as I have been hearing.
Picked up my cousin and asked him to drive while I try to listen for the rattle. Even with all of the AC pieces off, I couldn't pinpoint it as it now started to sound like it was coming from under the dash (maybe between the glovebox and dash?). I started just banging around in that area. I gave the A-pillar and good tap and the rattle stopped. I haven't taken the A-pillar apart yet, but will get to it soon and will add some foam in there. I still don't know what the rattle is but at least it looks like I am moving the right direction.
I went through countless posts trying to nail this down and was convinced it was the same as Edgy01 had posted here --> https://rennlist.com/forums/997-foru...heel-well.html
It was not. I then took apart the whole passenger side AC vent/duct and side panel that meets the door. The duct was loose but it was all plastic and did not look like it would be making the same noise as I have been hearing.
Picked up my cousin and asked him to drive while I try to listen for the rattle. Even with all of the AC pieces off, I couldn't pinpoint it as it now started to sound like it was coming from under the dash (maybe between the glovebox and dash?). I started just banging around in that area. I gave the A-pillar and good tap and the rattle stopped. I haven't taken the A-pillar apart yet, but will get to it soon and will add some foam in there. I still don't know what the rattle is but at least it looks like I am moving the right direction.
OK I can confidentially say that this rattle is coming from the A-Pillar towards the bottom (about 3 inches from where it meets with the AC vent). If the car sits for 3 hours or more, the rattle returns. A good tap fixes the rattle which means something is loose behind the A-Pillar.
Anybody have a DIY or can provide some tips for removing the A-Pillar?
06-21-2017, 12:09 PM
#25
Poseur
Rennlist Member
Rennlist Member
Have you ever had the front right wheel well liner out? If you take it out you will discover a couple of brake lines that may be your problem. They may not have been secured sufficiently. They will put out that noise.
06-21-2017, 12:59 PM
#26
Instructor
Thread Starter
06-21-2017, 01:06 PM
#27
RL Community Team
Rennlist Member
Rennlist Member
I did it twice, it is super easy. There are instructions out there... Start with the clothes hanger ... It pops upwards (opposite weight of clothes).. I think you have to then remove a screw and pull out but not remove the b-pillar trim,. Then just start yanking the trim piece from it's snaps starting at the B-ball forward. The tip of the trim has tabs that slide down into the dash so don't try and unsnap the forward end, just pull the loosened piece towards the rear and jiggle the end out.
IIRC....
Peace
Bruce in Philly
IIRC....
Peace
Bruce in Philly
06-21-2017, 05:07 PM
#28
Instructor
Thread Starter
I did it twice, it is super easy. There are instructions out there... Start with the clothes hanger ... It pops upwards (opposite weight of clothes).. I think you have to then remove a screw and pull out but not remove the b-pillar trim,. Then just start yanking the trim piece from it's snaps starting at the B-ball forward. The tip of the trim has tabs that slide down into the dash so don't try and unsnap the forward end, just pull the loosened piece towards the rear and jiggle the end out.
IIRC....
Peace
Bruce in Philly
IIRC....
Peace
Bruce in Philly
06-21-2017, 07:00 PM
#29
RL Community Team
Rennlist Member
Rennlist Member