1993 B190 with 460,strange noise!

[jhaun48]

I purchased a 1993 B190 from my brother who purchased it new.It has a 460 engine and is in great shape.The problem is a noise that happens once in a while which I can only describe as a whooooo that comes from the front passenger side of the engine when you let off the gas and the engine is idleing.If you rev the motor it will usually stop.He said it has done this since it was new but would never do it when he took it for service.Has anyone else ever had this problem?