engine noise

[cmd]

2003 h2, i have noticed a rattle coming from the motor at low rpm, In Park position if i bring up the rpms and let go of the gas you can hear a rattle as the rpms fall between 2000 and 1000 rpm, the same noise under load. Not sure if it is from the top end or bottom end of the motor? .Any one have any experience with this ?. cant determine if it is the valves or what.

Thanks