oh wow it's making noise just sitting there? I'm going to vote for ps pump or pulley. they do have a history of going bad, but typically lead to a chirp at the pump. Check your LCA's before it's too late anyhow.
2009.5 G8GT Premium OnyxRed Interior
corsa catback, vararam intake, cortex tune
custom audio, sharksfin, HIDs, LED Fogs, 20" MRR GT1's, Kayhan headunit