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Discussion Starter #1
I have a crazy rattle at 65mph and up. I have taken the entire dash apart . Fender liners . Everything . And from my research this doesn’t seem
Like a common one but it is almost undrivable on the highway . Attached a video. Andy help/ ideas would be awesome
 

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Nein Kinder
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@LFMWaffles - If it is speed related, then it could be caused by aerodynamic forces or by an out of balance wheel and tire. My first guess would be to look at the underbody panels (forward and middle undertrays and the rear diffuser). Ensure these panels are secure with all fasteners in place and tightened.

Two large bolts secure the leading edge of the diffuser and are covered by the middle undertray. I once installed these two bolts loose, then installed all the other fasteners. I forgot to tighten the two bolts and installed the middle undertray. While underway, the bolts backed out and rattled against the undertray . . . a heck of racket.

Glen
 

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Discussion Starter #4
I guess to add more clarification . The sound comes from RF . In front of passenger . And sounds like a small flag pole hitting the aluminum or something. It’s speed related but seemingly only because of the amount of air hitting whatever is rattling . It’s more random than something rotational . And yea checked every panel underneath
 

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Did someone drop a coin or something down defroster?

(Happened to me....)
 

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To me, I am going with the suspension related or aero related. Think of the frequency of sound a 67 pickup with a broken shock makes, even on smoothish pavement, that kinda rat a tat rat a tat. The speed variation due to either the normal wheel imbalance that is no longer restrained properly or the windforce getting high enough to start moving a panel in and out of the air flow.

If it really sounds like it is coming from the passenger footwell, perhaps it is telegraphing in that right rack mount.

Maybe take that passenger sill panel off and the foam underneath out, have a passenger reach in and grab the hoses etc to see if the vibration can be felt.
 

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Sold my Exige S
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It almost sounds like debris flapping around behind the passenger footwell vent leading to the blower fan. That might explain why you hear this more at speed from the increased cabin air flow. Does the rattling change at all if you turn the HVAC fan on?
 

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Nein Kinder
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@LFMWaffles - Another thing to check is the anti-rollbar mounts. They are on the other side of the forward bulkhead.

How did you check, and what panels did you check? . . .
It’s a pain, but thoroughly investigating each suspect is the fastest way to find the culprit. The forward undertray has lots of little fasteners near the lower trailing edge of the clam - I don’t remember any empty holes, so if you see any, they would bear investigation.

Glen
 

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I think that is the water drip from the A/C? No one will believe me now but I was about to suggest that.

Before I knew what that was for on my car, I added a plastic zip tie to mine since it looked loose.
 

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Discussion Starter #17
Haha! Crazy. Glad it was simple. Sad I spent so much time for a tiny stupid hose . Oh well. Hope it helps someone else someday
 

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I'm glad I had been reminded of the A/C hose recently in this thread.

My car started to make a rattling sound that sounded like a loose plastic fitting. It sounded like it was something near the passenger seat, possibly a loose fitting in the door.

Anyways it turned out to be the A/C hose. I had put a plastic tie there a few years ago but it seems to have come loose. I put another tie on there for now.

As I was posting this picture I noticed that there is a hole in the aluminum frame nearby. I might redo the plastic tie so it goes through that hole. In fact, that's what I had done originally.
 

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I should mention too that the noise was very annoying. It made the car sound like a cheap plastic toy.

I'm really happy that this noise only appeared now. I had just returned from an 11 day road trip to the US and had the car being making this noise I would not have enjoyed that trip at all.
 
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