If it sounds like metal rattling against each other or like you said metal scraping at that RPM, it is possible that you maybe spun a bearing. What does the oil pressure gauge read? In my LT1, at about the same RPM as you, it sounded like metal rattling against metal, like a loose header or something. I actually spun a bearing and the oil pressure dropped big time. My car is auto so it went into limp mode. I was told manuals don't go into limp mode so I'm not sure. Just talking for past experience.

 

When I start up the car it's at about 60-70psi. Then when it warms up, it drops to 20 unless I rev it up. When the RPMs rise, the oil pressure goes up to about 60 then when I let off of the throttle, the pressure drops back down to 20-30psi

 

your going to have to track the noise sourse. need to know if its coming from the trany or the motor, front of motor or back, top or bottom. you may have to drop the trany to make sure its not in the clutch system. try unhooking the alt belt to see if its got anything to do with alt, a/c pump, tensioner or ps pump. also make sure the starter bolts are tight.

 

It sounds like the noise is coming from around the passenger side floor board or over in that area. Maybe it's the starter or something loose in the interior. Or maybe the catalytic converter heat shield? I'll see if I can figure out exactly where it is tomorrow. It's hard to do when it's just me though. I need someone to hold my car at 2250rpms while I track it down lol.

 

Hmmmmm....a possible heat shield, now that's a thought!
To see if the cat shield came loose, which isn't uncommon, reach up, grab it, and try to move it up and down. Or rap on it with your hand to see if it makes a tinny rattle noise. If it does, it is. Oh yeah, make sure the exhaust has cooled off first, those cats get toasty.

 

Indeed, cats do get toasty, I have once touched the heatshield without thinking and it burnt me up.

 

It was the heat shield! Thanks Camaro69. You saved me a lot of grief.

 

Hey new guy, stop posting random usless crap all over the forum, k? Thanks! The issue was resolved almost a month ago. Your negative input was NOT needed!