sup guys

i think i hit a raised manhole cover, and now theres a rattling/buzzing sound when i get on the gas
its not constant, just at certain rpms and at certain throttle positions
itmakes the sound when starting up as well, until its warmed up
it goes away when i put in the clutch, but i'm not sure about that

also, when i shift hard at redline, it makes a whooshing sound, similar to a blowoff valve almost

performance doesn't seem to be affected .. and tranny still seems fine ?
i dunno if its relevant, but i drive a em1 w/ i/h/e and suspension

i looked under the car, no noticable holes, although i only gave it a cursory glance
any ideas?

 

Did you check your exhaust over? Sounds like a leak.

 

that's what i thought too, but i didnt find any holes or anything
but then again, i only looked for like a minute while i was gettin my oil changed

i'll check again though
any other ideas ?