I just bought a 240 a little while back and i'm noticing a weird sound when i start it up. It sounds like a big knock, like something is breaking looks right after if finished turning over.
here i'll try to describe it.

(key in) *start* chigga chigga chigga CRACK!...idle normal.............
and it does a big shake when it knocks. other than that the car drives nice except when i step on it about 3/4 of the way and further, the acceleration is still there but i feel the similar vibrations like as if i'm in a high gear (the rumbles).

let me know what you guys think?

 

i dunno wtf that is... my sr started doing that too, i think its because of the cold weather though.

try and make your sig a little smaller, shrink the text size or something

 

I like the sound to text translation lol. Might be your mounts. Mine did that when I would turn it off too and one mount was shot.

 

pop the hood, have someone start the car, watch the engine and see how much it moves left/right when the engine turns over. Or you can keep an eye on the engine mounts to see if they're done or not.