i scanned my car. no faults were reported.. i planning to change the transmission oil. is this advisable?

 

hi i faced the problem some time ago and posted the exact scenario in the forum.
changed coil pack, changed valves, changed MAF. nothing helped, and recently its diagnosed with transmission problem when whining/humming sound started. so the fluctuating rpm might be a sign of transmission starting to fail. get it fixed once u hear the whining/humming sound.