The AC idler pulley can fail causing a growling noise from the engine. A new idler pulley will be needed.
Car Problem Reports
Honda Civic Replace AC Idler Pulley to Stop Growling Noise
Honda Civic Problem
Visitor, 1997 Honda Civic, 152,000 mi
Loud bearing noise especially noticed at high idle. I initially greased (white) bearing, but eventually will replace idler pulley.