heres the deal, when i start the car cold it runs and sounds good but after ten seconds it makes this whirring kinda grinding sound but it stops and goes away. then with the car warm, when i rev it to 3k rpms it makes that sound again, but only at 3k rpms. any rev below or over then it is fine.like when i rev all the way to 5k rpms, when it passes 3k thats when it makes noise but when it goes over the sound goes away. same thing from 5k rpms, when it goes down and hits 3k it makes noise.

what could it be? the sound is not like that of a typewriter

 

something loose. check belts etc. If you have a spun bearing you'll see a bunch of metal bits in the oil and in the oil filter.

 

i will check if something is loose. i changed oil yesterday to 10w40 synthetic and it got quieter but the sound is still there.

any other reason/solution? i will post a sound file later...