You guys seem awefully fixated on farm animals...

Seriously though, when I start the car, within about 30 seconds there's this noise that comes from the engine, near the throttle body. It sounds like a low grinding sound, and from inside the car it sounds like a cow. Only lasts for a second or two. The previous owner says it's made that noise since almost day 1. She said a Honda tech told her it was the fuel injection system and it was normal. I've never heard of that.