timing belt question it looks lose and makes loud noise

i have a 92 talon esi and timing belt looks lose and makes a loud buzzing sound from idle speed to about 2500-3000rpm then the sound stops and it sounds normal from 3000rpm and up.my friend sold me the car and he says he put a newer timing belt on and the sound quit for a couple days then it started again he thinks the belt streched and its vibrateing bearings in the cam gears? any suggestions on why it would make that sound? please help i dont know much about engines.

Check the timing belt tensioner to see if it is putting the right amount of pressure on the timing belt.be careful driving with this problem if the timing belt slips or comes off you'll have big problems