So ive always had some rattles. It used to be the downpipe hitting the frame. Fixed it. Used to also be the exhaust hitting a bolt on the underside of the car...fixed that one too. Now I still have this rattle at 3500rpm. The car wont rattle above that or below that. it sounded like its coming from under the car and i can produce it at speed or revving in neutral. it doesnt effect anything except my sanity. I know its hard to troubleshoot this stuff since we all have different kits. I currently only have 6 manifold to head studs on because one snapped off ( before i went to the arp hardware ). The manifold has a small leak for 5 seconds then it warms up and i dont think the rattle is from that as its been that way for weeks now. Any ideas?

 

what clutch are you running? most aftermarket clutches add a rattle to the drive train. from 2000-3000 if I'm engine braking I'll get an annoying vibration.

 

The rattle I found at that speed was actually coming from the plastic pieces in the clips that hook in the soft top. I pulled those out, and the only rattle left is the Aluminum from the doors and fenders vibrating.... not much you can do about that though.

 

turn the radio up louder. seriously though, rattles suck. it def could be the clutch buzz. most people hear it on decel, but some here it just free rev.

 

check to see if the exhaust bolts are all tightened on all parts of the system. Also, i found that when part of my testpipe cracked, it started making vibrational noises at different RPM's. Check underneath the car and see whats up.

 

Oh I was under there for an hour. Took off all the vbands, checked all the bolts on everything. Its also not clutch buzz because i get that too but thats tolerable. I went out and drove the piss outta the car and now it barely will rattle and only on decel at exactly 3500 then the sound is GONE. Whatever, ill just turn up the radio more. Part of having a turbo car, too many parts so close to one another.

 

i had a rattle once and it was my dumptube hitting against something, very similar to you where it did it under certain rpm;s. we cut it a bit and now no noise

 

see thats the thing....nothing i can see is hitting. Ive looked everywhere. It will make the noise if you rev in neutral right at 3500rpm, it will make it when decelerating and accelerating when cold and then when warm mostly just does it on decel. I dont get it, its something metal scraping something or grinding against something. it doesnt effect driveability but its annoying.

 

ya, i would maybe at very least mess with the dumptube maybe angle it a bit different or maybe just wrap it with something to see if it makes it a bit quieter.

 

Andy, go all over the manifold very closely to make sure there isnt a small crack in the weld or something. That could definitely cause a vibration at that rpm. 3300-3500 rpm is where this engine has its most vibrations if one is going to pop up.