Slight rattle when Quest starts running

Not sure how to decribe it, But my wife has been complaining of a slight rattle in the van. I allways thought she was full of it because i never heard it. but then I realized I was listening for more of a engine rattle.

But yesterday when I started it i heard the rattle . It was almost like something was hitting the fan by the radiator. i couldn't see anything but thats what it sounds like. and its not contact its sort of does it for a few seconds then nothing and then back..

any ideas

What year Quest? There are a couple things I know of that the rattle could be, but I need to know the year Quest. If it's 04 or newer, then it could be exhaust gussets or B1 catt converter shield. If your model Quest is an 04 and up, these could be your rattles, feel free to contact me if you have any questions. gl... Oh yea, let me know your millage also, it may be covered under warranty.

2002 quest w/ 70,000 miles on it.