Need help diagnosing sound. (Driveshaft?)

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Apr 3, 2021 | 01:05 PM
  #1  
Hello all,

Was on the highway yesterday when I heard a loud metallic clucking and vibration underneath the center of the car for about 10-15 seconds. I immediately thought it was the transmission and began to get over to the breakdown lane. The noise ‘cleared up’ and then left a rhythmic sound which matches speed. I then thought it was tire related. I pulled over and inspected but did not see anything wrong with the tires.

Drove home fine with no other issues besides the noise. No loss of power, no check engine codes, no abnormal shifting, etc. I checked psi and tire tread, some camber wear, but I’ve driven with worse.

Put it on the jack stands today and have pinpointed it down to the driveshaft area. Can’t see anything but the sound definitely comes from the center of the car and increases with speed while driving down the road.
Here is a video idling on the stands;

Anyone have any ideas?
TIA


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Apr 3, 2021 | 01:27 PM
  #2  
Bad flex disc?

Quote: heard a loud metallic clucking

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Apr 3, 2021 | 04:16 PM
  #3  
Sound like the center bearing for ur driveshaft, remove the heat shield in the middle and look for wear on the outside of the driveshaft center bearing.
(No need to remove exhaust)

most of the time, rubber around the bearing qear out and bearing boucing around the cage
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Apr 3, 2021 | 04:18 PM
  #4  
[QUOTE=BLKROKT;8307218]Bad flex disc?




Bad flex disc will be more like an clunking noise when shifting or during acceleration
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Apr 4, 2021 | 01:40 AM
  #5  
Agree that it sounds like it has something to do with the driveshaft and/or components thereof. Had mine replaced at one point for a clunking noise under power. I assume your car was in gear on the jack stands?
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Apr 4, 2021 | 06:34 AM
  #6  
Sounds like an evil spirit knocking around in there with a hammer....

Did you do this video with the transmission in drive and engine idling? When the driveshaft support bearing in my W202 C43 was dying it made a whirring noise not a knock. Try grabbing the shaft with your hand (engine stopped of course) and see if it has excessive movement. You are talking of the noise from your 12' coupe. How many miles driven?
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Apr 4, 2021 | 10:45 AM
  #7  
Quote: Agree that it sounds like it has something to do with the driveshaft and/or components thereof. Had mine replaced at one point for a clunking noise under power. I assume your car was in gear on the jack stands?
Quote: Did you do this video with the transmission in drive and engine idling?... You are talking of the noise from your 12' coupe. How many miles driven?
Yes, it was in gear/drive while idling on the stands.
Yes, on my '12 coupe. It has ~105k miles.

Thank you all for the replies. Haven't had time to get back under there again due to family obligations with Easter today.
I will most likely bring it to my local indie shop tomorrow or Tuesday. (Car is still covered under 3rd party warranty)

Leaning more towards a bad flex disc then bearing. The clunking noise is consistent and increases with speed/load.
Wouldn't the bearing sound more irregular, like a random rattling or bouncing?
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