Hi, I'm new here and new to BMW. Just bought an "08" LT and notice that when going up thru the gears, i can hear a metallic sound, a bit like the timing may be advanced or retarded or the wrong fuel is in there. It goes when in top gear above about 60mph. Met a guy with one last night and he said his does it and it's because they are run very lean. It is under warranty, but just thought you'd probably have some ideas. Thanks in advance.