it doesn't sound like an engine sound it sounds like a shield on the motor or something is loose but cant figure it out, does it at constant speed and accelerating at 2000-2600rpms, can anyone help me, before the rattle drives me insane

prollly your heat sheild bolted on your floorr, get someone to rev it up...and watch..im sure of it though

cool thanks i will check that

that or check the heat sheild on the cross over pipe. had the same problem and that shield was cracked.