H sante fe - ocasional buzz from the engine when

hyundai sante fe manual 2003- ocasional buzz from the engine when no or little pressure on the gas pedal- could it be timing belt - it also seems to be high revs when just started and a couple of gas pedal depressions and it settles. low range of tolerance between the lowerower gears ie betwwen 1,2 ans 3.

No sure if these are symptoms of the same problem or all different.Any help appreciated - regards Bob