So, I've got my 99 Buik LeSabre, and I love it, except for a single problem with it. At ~1400 RPMs as ou start off in each gear, it makes a noise that I'm about sure is grinding. I can't peg it down to a specific location, and it only does it when the car is in gear - if I rev to 1400 in park or neutral its fine. Also, it doesn't really happen when the car is cold, but once its been running, it gets pretty noticable. I'm thinking tranny, but I know next to nothing about automatic trannys....ideas?