Ok so when I shift from 1st to 2nd or 2nd to 3rd there is this hell of a loud rattleing noise thats pretty much driving me insane and is quite embarrasing when im driving slowly past people and other cars. lol...well anyways, does anyone know what this could be? it does not doing from 3rd to 4th or 4th to 5th and it does it when I accelerate only, if I do not accelerate then its fine....thanks for the help!

 

might be a bearing, but it could also be ur timing belt tensioner.
1st check to see that ur timing belt is tight and the tensioner checks out, cuz the tensioner could be failing making the timing belt slip off and hitting the plastic cover. if it does it check out, i think its going to be a bearing. not sure which one tho.... hope this helps

 

could be your belt. Mine did that and I just got a call from my girl that it snapped off. So I guess my swap is coming sooner than expected.

 

Might be a heatshield on your exhaust somewhere. My car (Subaru) does this only in 1st and 2nd gears, no noise or ratteling noticable in any other gears.