rough sound when accelerate

Hi all,
When I accelerate quickly from a stop, I sometimes hear a rough/grinding noise which goes away after a second or two. Has anyone else had this problem? It seems to be coming from the engine area, but I realize it could be coming from almost anywhere. Two years ago I had a similar problem with my starter. I guess I'll start there first! Thanks.
Matt

I had a bad tranny mount and left engine mount. Changed those and no more noise. Mine is a 4.0l , auto tranny.

On mine, the fan hits the shroud when you really goose it. The wear on the shroud is visible.

Thanks for your help guys. Matthew, which of your two fans is hitting the shroud? Was it because your shroud is bent, or because your fan is misaligned? Thanks!
Matt