This is a tough one for me. Noise is about a week old. '86 2.8 with 4 speed stick. Noise is tinny and metallic. Sounds like when we used to put cards on our bicycle spokes only this card sounds like tin. Noise only happens when accelerating through 3400 to 3600 rpm. Louder and longer in first and quieter in second. Gentle or hard acceleration doesn't matter. Warm or cold doesn't matter. 99.9% sure noise is external. sounds like a flywheel rubbing the dust cover but it's not. I can't seem to find where the exhaust would be making the noise. Wheel bearing seems fine and dust covers over hubs aren't scraped. Noise doesn't happen in neutral so I have ruled out an exhaust note. Heat shields are tight. What an odd deal. Noise lasts only for about a second and a half starting at 3400 rpm in both gears. I can't hear it in 3rd and 4th but I think it's there and just too quiet to hear. If I hover it around 3400 while driving I only get it once and can't make it stay. Then the next time through that rpm I get it again.
Noise sounds like it's coming from low on the car drivers rear.
Thanks.

I think I might have the same sound on my 85GT 4sp. Happens mostly in 2nd but at times in 3d. To me it's a sound like a piece of thin metal vibrating from air or vacuum moving it. Also sounds like it's under the car. Only latst for a second or so.

Have not found mine either. Have been thinking of disconnecting the vac line to the brake booster to see if that would make any difference.
I've think I've eliminated clutch or TO.

[This message has been edited by Dodgerunner (edited 11-01-2007).]

Yep it reminds of me of a tin fan blade hitting its shroud for just a second. What puzzles me is I can't make it happen sitting in neutral.
It definately sounds outside the motor.
Mine is not intermittent though. It's guaranteed to happen at 3400 rpm.

mine did that too, right at 3000 to 3500 rpms is would make a metalic rattle, externaly, i found it was the big heat shield that runs between the cat and firewall, it was rattling, i tightened up the screws and bent it all to hell to put tention on it.. noise gone

dont know if that helps... but it did mine, and also i had another noise awhle back, sounded the same., turned out to be cat shield.

Mine still does it with the heat shield out so know it's not that.

I'll go check that heat shield. It's the only one I didn't check.
However while coasting today I was able to make the noise in neutral. Repeatedly and at the same 3500 rpm. So now I am definitely thinking an exhaust rattle.

Ahh to make a short story long, when I replaced the clutch a month back I forgot to put the flywheel dust cover on before stabbing the tranny. So I took my tin snips out and trimmed it so I could put on afterwards (I didn't want to remove the starter-- it was late and I was tired of motors). Well I thought that I had straightened it up nice but after three weeks of driving (maybe some heat?) it warped and was barely hitting on the flywheel rivets. Nice to know how out of balance things are at 3400 rpm. So thats one of the 25 or so noises tackled. Thanks for the input.

if you want you can stop by myplace and ill take a look at the other noises and you can see how things are going on mine. and you can see our newest family member! im off all this weekend...