my 2004 chevy aveo making noise in timing belt area

A few days ago i was making a trip about 60 miles one way i got turned
around and at slow speed my aveo started making a load rattling  type
noise but this only happens at low speed when i get it up to 40 mph or
higher sounds stops it is coming from the timing belt area under the cover i
have been driving it no warning lights no loss of power or anything oil level
is good i have so many people telling me different things what could it be
like i said it runs fine when up to speed and after it warms up the noise
dims down no smoke or warning lights runs good when driving no loss of
power or anything..