I have a '01 BMW X5 3.0. I was driving on the freeway and as soon as I came out, it started losing power. The RPM's would hit red and I'd move a few feet. Now it barely moves. It has the original ATF. I opened the fill plug and drained a couple quarts and put in 4 thinking that it may have leaked a bit but I am still having the same problem. Any ideas?