My 2002 Buick LeSabre has been "herky jerky" as of late. My car will turn on (turn over), the RPM's are correct but when I put my car in drive and once it tries to shift, it feels as if something's off and it won't allow me to have any forward momentum. Actually, once it tries to shift gears, I must turn off my car or keep my car in drive and have it move backwards. My brother has said it may be a motor mount bolt not being tight which makes sense because of the way the engine seems to throw itself at times. My car used to be a smooth ride but now all I'm worried about is making it home safe. Please HELP!! :)