my gsr integra has a little over 100,000 miles and the engine makes a rattling noise only from 3000-3500 rpm, it never makes the noise at any other time throughout the rpm range. I'm wondering what is causing this noise, any help would be greatly appreciated. Thank you.

 

It might be either one of your heat shields on your exhaust being a little loose and vibrating or a small exhaust leak. I had a couple pinhole exhaust leaks and my exhaust would become very annoying at around 3000rpm and continue until around 4000rpm. Hope that helps.