The AC idler pulley can fail causing a growling noise from the engine. A new idler pulley will be needed.Google+
Car Problem Reports
Honda Civic Replace AC Idler Pulley to Stop Growling Noise
Honda Civic Problem
Average Mileage: 159,500 mi (136,000 mi - 192,000 mi)
Visitor, 1998 Honda Civic, 180,000 mi
One day I was driving to work and started my car. Well my ac is always on because I always use it. I turned my car on and heard the rattling before it actually started so I tried starting it and it started fine and ran fine all the way to work didn't act funny on the highway and whatnot. Except for that rattling. Couldn't figure it out until I got to work shut the car off and kept the keys in 2nd tier to keep the AC on. Since I still heard the rattling I checked under the hood. Sure as hell it was coming from the front only when the AC was on
Visitor, 1996 Honda Civic, 192,000 mi
idler is growling.
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.