rattle noise really loud

i have a 1993 ford tempo. when i start the car it sounds fine once in awhile. now when i put it into reverse that's when the rattle starts. sometimes even while on idle or should i say in park it rattles. it sounds to me like it is comin from the passenger side around the front. also while driving low speeds and when i come to a stop it rattles like crazy. it is really loud and if it is in park for a long time it sounds like a diesel engine runnin. it is nerve reckin and i have no idea what it could be. also no mechanic seems to know and i don't want them to look until i know for sure what it is and how much it would be. any help would be greatly appreciated.

it is the harmonic balencer, all you got to do is get a mechanic to order a new one for your car and have him put it on. Problem fixed!!!!!!!



p.s. the same thing happened to my car and that is how i got it fixed.

thanks.