look here, I had the same problem except on my SVT, which is now sitting at HMS waiting about $2,000 worth of rebuild. Not to scare you or anything, but my car showed a lot of the same syptoms as yours. A Rod bearing is bad, so I'm looking at new crank, rods, bearings, seals blah blah blah.. about $1,000 in parts and about $1,200 in labor (which I have a feeling is a really damn good deal).. Anyways, like I said, don't wanna scare you but, this is my situation. Oh and the SVT is a 2000 with 51,000 miles on it.
paul