96 Trooper - "Buzzing" at highway speed

Greetings,
I have a 1996 Trooper with 112k miles. When driving at highway speeds, say 40+ mph, there is a distinct buzz that comes from the dash where it meets
the windshield (at least to my ears while driving). Most of the time it will stop if I let off the throttle, but sometimes it will carry on even after I do this.
It is a very odd medium-frequency, plastic-metallic sound if that makes any sense. The frequency stays constant once it starts, that is, it doesn't get faster/louder as RPMs increase or decrease. It just carries on until I get down to street speeds or ease off the throttle.
Has anyone else experienced this? Could it be something loose at the firewall? Maybe the throttle cable isn't all the way secure and is banging against something? Overall driveability and performance don't seem to be affected and the truck runs like a top otherwise.
Thanks, -Mark
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Mark, you may have the same problem I have.... I had my windshield replaced on my 98 Trooper. The boneheads that put the new window in screwed up the plastic trim around the window, so it doesn't hold itself flat against the window as well as it did when it was over the original glass. As I went down the road at highway speeds, it would vibrate and drive me nuts. Finally, I figured it out by putting a strip of clear plastic packing tape over the trim, so there was no gap between the trim and the windshield glass. I found that mine was coming from the vertical trim strip on the passenger side. I ended up just leaving the tape there - I don't feel like messing with it any more and since I'm totally fed up with this truck due to lousy gas mileage and oil consumption at highway speed, I don't really worship it any more, or I'd have it fixed properly by a competent glass shop.
You might want to try this - it doesn't cost a dime and you just may find your problem is gone when you put the tape on it. Let me know how it works.... hope it helps. r/ Steve

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Would a bit of silicone sealant do the same job in a more permanent manner?
Wesley

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Wesley, it would... perhaps a bit messy - and in Washington it was too wet, and here in Florida its too hot and too many mosquitos to go out and do that outside (and I only have a carport) - so tape will work just fine until it gets cool. But, yes, it would do the trick.
Steve
--
Stephen P. Reimers
Naval Salvage Officer
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