Rattle/Resonance help needed!
 

This is technically not an audio question, but I think it needs an audio expert to solve (read on, you'll understand why).

A lot of people have been getting either a rattle or resonance in their dashboard. It seems to come from around the center area near the instrument cluster. The rattle/resonance occurs around 2.5-3k rpm and seems to be much worse under load. It also gets worse with aftermarket exhausts (makes sense, as they are much louder).

I've tried every normal route including the dealership; they said it was a faulty instrument cluster, but the new (supposedly non-faulty) cluster didn't change anything. The only thing I can think of is to ask you audio experts what you do when your hi-decibel audio systems cause similar problems. I'm sure Dynomat would probably help, but how do you normally go about determining which part is causing the problem?

For the record, I'm guessing this is a resonance issue, as it seems rattling would be more spread out across various rpm levels.

I have had a weird resonance issue from somewhere around the middle of the dash, sounds like it's behind the cubby area, that occurs ONLY on strange road surfaces .......... like the extremely grated ones that are designed to make you drive very slowly, like miniture speed bumps one after the other. This will make that resonance go crazy and very loud. Other than that type of surface, I can't duplicate it.

Now that you mention it, I have it too. I thought it was my radar detector vibrating- and never bothered to check it. I took it down and went for a drive and sure enough, still there.

I need to pull the dash apart this weekend (finally going to install the PAC-SWI for my stereo). I'll see what I can find.

Definitely let me know if you find anything out... this has been driving me nuts.

i just found this yesterday, it is the defrost vents. at least for me it is, and only when the a/c is on. you can shove a piece of foam or something in there to help. i just kinda "hit" my vents and the problem went away, but it'll probably show up again without the foam.

I'll check that out and see if it works. Thanks!

hope it works!

Well, turning off the climate control doesn't stop it, but I think you might be on to something regarding it being the vent that rattles? Do you know how to get to whatever tightens the vent to the dash? I see a disc-looking object on the vent; I'm assuming that you pop that off with a screwdriver to access a screw or bolt or something, but I don't want to pop it off until I'm sure that isn't breaking something.

I have no idea. you can download the service manual from somewhere here on the forums and that should show you the exact details involved.